Clockwise from top right are:
90 degree full flow swiveling -6
180 degree full flow swiveling -6
Non-anodized -6 end, used for welded fittings, made by Earl's
Brass barbed fitting, never to be used in aircraft
-6 swivel fitting with 1/8" pipe outlet - good for pressure or temperature sending
Same thing made by different company
AN833-6D bulkhead elbow - a fitting like this is far more restrictive than a full flow 90
| Thank you.
| | William
| | Subj: Front Starter Kit Specs
| | Date: 8/31/03
Friends,
| | A number of people have asked questions about how the Front Starter components are assembled.
I've added several photographs, a description and instructions to the Online Catalog of Products from TCA at a
special Front Starter Kit Link. Also, all components of the Front Starter System are now
listed with links to descriptions and pictures at the Online Catalog at www.FlyCorvair.com.
| | Thank you.
| | William
| | Subj: Low Profile Front Starter and Ring Gear
| | Date: 8/30/03
William, what is the smallest diameter ring gear and starter combination that can be had for the lowest view over a
close fitting cowling?
How much more complicated is it to go to a rear ring gear set to get the lowest view over the nose?
Sorry to have missed your outing last Saturday.
| | Sam Sayer, Zephyrhills, Fla., Karibird37@msn.com
| 
| | Reply from WW:
| | The Corvair can use a 10.5" ring gear in the front. Putting the starter on the back of the motor requires
modifying the oil system and changing the location of the filter and cooler. This presents a significant amount of
complexity which many people do not wish to introduce to the motor. The above photo is a view of my current low
profile front starter. You can see more photos at the eBay auction of the
100hp Corvair Conversion I built - but the site is only up until the auction ends Sept. 4. I'm working on a
starter nose which will further reduce the current height by 3/4". But I have the setup in the
photos available right now, and it requires no oil system modifications.
| | Subj: PIET - Road Trip
| | Date: 8/29/03
Had a fun weekend, especially at your place. Can't wait to build up these 6 engines.
I am sending you a UPS package, but can't send to a PO Box. Do you have a shipping address?
| | Did you look at the three engines you got a call about? If you are not going to buy them, are they avaialble?
We still need three more.
More Later,
| | Barry Davis, Pietenpol, Georgia, bed@mindspring.com
| Each of the six guys from Georgia in the photo above is building a Corvair powered Pietenpol. Look for their story in
the next issue of The Corvair Flyer newsletter. We'll be mailing these in early Fall, so be sure to subscribe or renew now.
| Reply from WW:
| | We had a great time also. Our hangar address is 210-11 Cessna Blvd., Port Orange, FL 32128.
| | There were actually four motors there, and I bought them all. They had been outside for a long time and were really only
good for miscellaneous parts. At $60 for all four, the price was right. Keep looking up in Georgia; you're bound to find
more with a little work. If anybody in the Atlanta area knows of a source, please e-mail Barry directly.
| | Subj: My Corvair engine runs for the first time
| | Date: 8/28/03
Add me to your list of having a running Corvair engine.
Attached is a picture of my corvair engine running for the first time on my Pietenpol fuselage. Hope to have the plane
finished later this fall.
Thanks,
| | P.F. Beck, Pietenpol, Barnwell, S.C., pfbeck@barnwellsc.com
| 
| | Reply from WW:
| |
Congratulations! I'm sure it's a proud moment for you. The pictures you've shown us all along have always displayed good
craftsmanship and work. I'm sure the engine will reward you with many happy hours of flying.
Keep us posted.
| | Subj: Which Engine
| | Date: 8/27/03
I received your Conversion Manual today and I can't wait to get started. I will get the one page Registration and
Liability Statement sent out here in the next day or two. A little busy here with the forest fires going on here and I
have 2 flight crews in my guard unit out fighting them.
| | I might have jumped the gun, but before receiving your Manual, I purchased 2 Corvair engines. Granted I might have
paid more than I should, but I have 2 engines!
I just want to get a clarification on the engines I do have.
The last 2 digits on the serial numbers I have are YM and YN. These are the 110 hp and are 1964, correct? Are these the
engines with the cylinder heads I should be concerned with and will these engines work for my application?
| | I am currently starting my KR-2S (modified) project, after being away for close to a year being deployed to
Afghanistan, so coming across these engines has sparked my interest in building again, plus after selling one of our
vehicles and the wife giving me 75% of the money for the sale to go towards my KR project.
Any advice will be greatly appreciated, since I have never taken apart a piston engine before.
Thanks in advance.
| | John E., KR-2S, Independence, Ore., jesch@earthlink.net
| | Reply from WW:
| | You may have jumped the gun. Both YM and YN engines could be either 164cid or 145cid. The only way to tell for sure is to
remove the top cover, rotate the crank and look for the 1/2" tall numbers that read 8409. If the crank says 5607, you have
145cid engines. If you send me the number on your cylinder heads, I'll be able to give you more specific information about
them. If it turns out that these are 145cids, a good source for you for a 164cid core would be The Corvair Underground. My
Oregon geography isn't good enough to say how far apart the two of you are, but he certainly would be able to provide you
with the correct core.
| | In either case, keep building. We're glad to have you back from Afghanistan, and it's good to hear that you have a very
understanding spouse. Your enthusiasm and her support is the proven combination behind many a successful airplane project.
| | Subj: Where to Buy Motor Mount Bushings
| | Date: 8/26/03
Gettting ready to mount the Corvair to a copy of Your Pietenpol mounts. Can You give me an idea of where to get those
neoprene bushings for the mount isolation? My local car parts guys say there are many different types.
Thanks,
| | Steve, Elma, Wash., srs1@techline.com
| 
| | Reply from WW:
| | Above is a photo of the sway bar bushings we use, Energy Suspension Part No. 9.8105RC. They're available from our local Auto Zone. If anyone
has trouble getting a set, send $20 payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802. This will cover
mailing you a set in the U.S.
| | Subj: Suggestions for next Manual revisions
| | Date: 8/25/03
Hey William, I had another suggestion, this time for your next revision of
the Manual. (And by the way, this last Manual is a vast improvement over
the first one. Great job!)
Picture this scenario: My hangar is a 50 minute drive from my house. So I
drive out to the hangar to work on something, and when I get halfway into a
procedure (whether working on the engine or on the airframe), I discover I
am missing a particular size bolt or a particular lube or tool or
something. Murphy's law says it will be something I cannot get at the
Chief Auto Parts, but needed to have ordered last week from Larry's or
Clark's or something.
It would improve the plans immensely if, for each of the chapters
(Disassembly, Case Assembly, Rod, Piston, and Cylinder Assembly, Head
Assembly, etc. etc. etc.), you had a list of tools required, parts required
and materials required.
That way, a builder doesn't get started on a particular procedure only to
discover halfway through that he doesn't have a particular item that is
required. He can make sure he has ordered all the parts and expendables
and has all the necessary tools for that procedure.
I know you aren't trying to replace the Corvair Service Manual, but even
for the procedures you do cover, it sure would be nice to have that list in
one place, easily digested, at the beginning of each chapter. It would be
especially handy for those of us who are doing this for the first time, and
have to basically go out and buy every bottle of anti-seize, every can of
spray paint, every can of STP, every valve compressor, etc.
Thanks,
| | Dave Morris, Dragonfly, Bedford, Texas, Dave@davemorris.com
| | Reply from WW:
| | Your suggestion is a point well taken. I am getting closer to this ideal with my Engine Assembly Videotape Series,
which helps
people visualize what they'll need for engine assembly. One of the things I've worked on before, which I think would be most
useful to builders, in addition to what you've said, is a flowchart on the sequence of building an engine. I saw one of
these done for the Sonex aircraft by the factory and it was very, very good. I'll have to put some more time into
developing one of these for the Corvair. I'll keep your suggestion in mind as well and put
it to work when I can.
| | Subj: How many passengers?
| | Date: 8/24/03
Hello! First of all what an impressive engine you have. I'm new in the homebuilder aircraft. I don't have any
experience. I'm just wondering: If I built my own
plane, can I use multi-engine plane using your engine and how many passengers you think can lift? Thank you.
| | Leo Pestano, AandL121699@aol.com
| | Reply from WW:
| | Thank you for your compliments on the motor. Most single engine Corvair powered planes are two-seaters. A small
percentage are single-seaters, and I do not know of any which have flown three or four passengers yet. There are at
least five people working on twin engine Corvair powered planes. Four of these are two-seaters. But the sky's the limit
when it comes to how many engines could lift how many people. It's easy to imagine a tri-motor that would lift six people,
or a four-engine airplane which would carry eight. If you're interested in designing an airplane, the best place to start
is with John Roncz's Sport Aviation articles.
| | Subj: Hypereutectic pistons
| | Date: 8/23/03
Hello, this is Ted Phillips. I haven't wrote you for awhile partially because of my busy schedule at work and my Corvair
re-build!
Getting ready to fire my baby up hopefully within the next 30 days. This is a very proud and exciting stage of my plane
build.
The reason I am writing you (besides catching up) is I feel that as a Manual owner I should inform you of the one deviation
I have made from your Manual. I just know that I'm going to get an ass chewing for this, but I have used Clark's Hi-Tech
pistons in my engine. The reason for this decision is based on the fact that during the past winter I was told by Clark's
that forged pistons were not available and may never be available again! I felt at the time that I only had one way to go,
now I know that forged are available but I am wanting to use the pistons I have installed.
I know there are detonation concerns with the Hi-Tech pistons, but I thought to manage the risk I would slightly retard
the timing and only use 100LL fuel. Do you think these precautions would be adequate ?
I know that you are no fan of eutectic (sp) pistons but they must be better than cast, correct?
Let me know your thoughts. If you think it is a very poor decision for me to use them I will defer to your judgement and
save for the forged pistons.
Thanks for your time,
| | Ted Phillips, GN-1, Chariton, Iowa, tedanddj@mchsi.com
| | Reply from WW:
| | You will not get an ass chewing from me. Although I grew up in a U.S. military family, I believe it's a myth
that military fathers teach their sons how to deliver first class ass chewings. All you'll get from me is the benefit of
my knowledge and wise counsel. The decisions, as always, are all yours.
| | Hypereutectic pistons are cast pistons. There are only three ways to make pistons: forge them, machine them
from a billet, or cast them. A hypereutectic piston is a special version of a cast piston. While they're better than
original cast pistons, they're still substandard to forged pistons for flight purposes. I cannot recommend that you fly
hypereutectic pistons because I've never flown them myself. But, I do believe you could fly them on 100ll with reduced
timing and careful attention to CHT, etc. But this is far from a ringing endorsement or a blanket approval. Now that the
TRW pistons are back in stock, you always have the option of changing the ones in your motor out for forged pistons. BTW,
I'm sure that TRW pistons are cheaper than hypereutectics. I don't think you'd have the same margin of safety with
hypereutectics that you do with forged. The decision is yours to make.
| | Subj: Skystar Series 7
| | Date: 8/22/03
Your feedback service is one of the best I've seen. Answering all these questions would drive me nuts, especially the
redundant ones.-- Here's another one. Will the Corvair engine work in the Kitfox Series 7 by Skystar? If so, can we get
the 125Hp I'd like to run?
May God continue to bless you with an abundance of patience :-)
| | Russ, rspmaggio@msn.com
| | Reply from WW:
| | A 3,100cc Corvair motor will deliver the kind of power you're expecting, and is among the lowest weight
engines in this power category. But of course the biggest advantage would be the fact that such a motor could be built
for about $4,000 in parts and a satisfying investment in time.
| | Subj: 65 110 RB engine
| | Date: 8/21/03
Hi. Is a '65 110 engine with an RB code suitable for conversion? It is not
listed in your Manual one way or the other, but the Corvair Underground
book lists it as a "manual trans" the same as RA, another code you do not
recommend. Am I to assume it has the same low compression heads?
| | Max Marshall, Manual #5615, byteajoern@webtv.net
| | Reply from WW:
| | The reason why RB letter coded engines aren't in the Conversion Manual is that they're 140hp 4-carburetor
engines. However, if you have the bottom half of one of these engines, it is perfectly suitable for conversion to a
flight engine following the practices outlined in the Manual. You will just need a set of acceptable cylinder heads.
Likewise, an RA motor can always have the bottom end used, but the cylinder heads have to be verified to ensure they
are correct. Many RAs came with cylinder heads which end in the digits 0708 - these are not acceptable heads, but they
interchange with plenty of other sets that are.
| | Subj: Corvair Jugs
| | Date: 8/20/03
Just got my jugs back from Clark's; they were able to hone them out and keep them stock. I also ordered a set of long skirt
pistons (they only have about 7 pistons left) and I'm awaiting the arrival of my Safety Shaft that I ordered from you a
couple of days ago to get my crank tapped. Before I bore you with my happiness, I was wanting to know how much it would
cost me for you to make me an engine mount for my KR2S and what information you would need to make it? I'm making it a
taildragger.
Last thing: The gentleman from Indiana who was at Sun 'N Fun when I had my case there and we removed the studs, I think
his last name was Hudson. Do you have a good e-mail address on him? I would like to see his finished product. Thanks for
all you and Grace and the bunch do for all of us...
| | Bob Glidden, KR2S N181FW, glidden@ccrtc.com
| | Reply from WW:
| | There's a picture of Larry Hudson, his son Cody and the motor on display at Brodhead at the News from The
Corvair Authority page on www.FlyCorvair.com. The Hudsons did a very nice job on their engine. Larry's e-mail address
is indyannie_1999@yahoo.com.
| | I have a jig to make motor mounts for the KR2 and KR2S. As long as your fuselage has a firewall with the same
vertical dimensions as the plans, my mount will work with it. The taildragger version is $450 + S&H. The tricycle gear
version costs $500 + S&H.
| | Subj: I'm interested in converting
| | Date: 8/19/03
I apologize if the answers are in your Manual, but these questions come to my mind when trying to decide to have a go at
building an engine based on your Manual.
I am technically savvy but own no specialized equipment. What investment in tools is required to be able to do a
Corvair engine conversion?
Does your Manual start off with some guidelines on what engine to start with? It seems one must pay attention to
serial number or model/year in order to have a successful conversion.
The 120 HP engine has a larger bore. Is there any info on how that is obtained? Is the standard engine bored out
(seems like a lot of metal has to go) or do you purchase new cylinders/heads? Where does one get pistons? I assume the
larger bore can work with the regular valves because the lower rpm (compared to automotive use) gives the engine enough
time to suck the extra air in?
| JP, jspeyart@pi.net
| | Reply from WW:
| | The majority of my customers are first time engine builders. The engine does not require any special tools.
Perhaps a $30 beam type torque wrench from Sears is the only thing beyond wrenches and sockets. It certainly doesn't
require a lathe, milling machine or anything like that.
| | The Conversion Manual contains all the information you need to know about how to choose an engine: all the casting,
stamping numbers, etc. It's available for $59 in the U.S., and $74 for international orders, including Canada, payable by
check or money order in US Dollars to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card via
PayPal at the www.FlyCorvair.com Online Catalog.
| | More info is in the Manual, but in a nutshell, the 120hp engine is made by putting 94mm VW cylinders and
pistons on the Corvair motor. The machine work required is provided at a very modest cost by the man who offers the kit
to do this modification. Your assumption about valve sizing is quite correct, also.
| | Subj: Candidate Engine
| | Date: 8/18/03
I've run across another candidate engine through a member of a Corvair
club. The owner has sent me a couple of photos that I was hoping you would
look at and render your opinion. The seller says it's a 1967 110 HP engine.
He acquired it from someone in Georgia and has had it in storage for the
past 12 years. Prior to that I have no history. He claims the crank turns
freely and that the matching heads are #3878566. Asking price is $150.00
OBO. I notice it does not have the Harmonic Balancer. I am suspicious about
the block serial number. It almost appears as it has been re-stamped and
that the original numbers are barely noticeable just underneath the current
numbers. Just my imagination? I intend to look at it next week and will ask
to pull the top cover off so I can inspect the crank. Any comments or
advice is always appreciated, Thanks for your time,
| | Ron Franck, franck@geneseo.net
| | Reply from WW:
| | Your plan to take off the top cover and look for 8409 on the crank is a good one. Judging from your
information, I suspect the motor is a 1967 110hp. Some of these engines did not have balancers from the factory. I owned
a 1967 Monza with this exact engine; it had never been touched when I got it, and yet it had no balancer. GM did some
odd things the last three years of production. Let us know how it turns out.
| | Subj: Preceptor for Corvair
| | Date: 8/17/03
I have gone thru your list & haven't seen anyone ask this question: Has anyone tried a Corvair in a Preceptor Pup (2 place)?
| | Doug Baird, DBaird@barroncollier.com
| | Reply from WW:
| | I do not believe anybody has done that particular combination yet. I remember that Ultrapups were equipped with
full VW engines, but I have no knowledge of what the upper limit of weight or hp is for your bird. The Corvair would
certainly have enough power for a very impressive installation if the engine met the airframe's design specs.
| | Subj: Turbo Corvair
| | Date: 8/16/03
For several months, I've eagerly awaited your article on turboing the Corvair to appear in the Summer issue of The Corvair
Flyer. This is of very great interest to me, and I am sure, to many others. What happened? I have no doubt at all that your
plate is very full; however, please let me and others know what the status of your turbo project is. Even preliminary
information would be much appreciated. Thanks,
| | G. Andris Vaskis, Westminster, Md., vaskis@gte.net
| | Reply from WW:
| | Yes, you're quite correct that the plate is very full. The turbo motor is essentially done. The work was
interrupted by Oshkosh, but we are back on track. We have an airframe lined up to fly it on in the Fall after we run it
on the test stand. I'm not sure, but we may get it running on the test stand before we send out the next Corvair Flyer
newsletter. Be assured that it's of a personal interest for me to get it done, and that there are no technical
difficulties standing between me and success, just a matter of getting a few more hours in here and there to get
the engine ready for the stand.
| | Subj: 88mm VW pistons/cylinders
| | Date: 8/15/03
Hi William:
I have reported to my group (3 builders) our meeting at OSH. All the information you gave me was shared with them.
If you remember, I told you that one of our buddies does want to use the VW 88mm cylinder-piston produced down here
by Mahle.
Although I respect him in this regard, I'm trying to talk him away from this approach because I think this will represent
messing too much with the engine by introducing non-original parts in it.
Nevertheless, I told him I would contact you in order to know exactly what would be involved in this.
The 88mm pistons would require him to rebore the case?
You told me the VW piston pins do not match the bore in the rod, and that the rod should be re-bored. Is this very
specialized work, or something a good machinist would do?
Is there any other work to be done in the rod beyond that?
I suppose some work has to be done in the heads also to accommodate the new dimensions. Is that so?
Any other thoughts?
Best Regards,
| Oswaldo, KR2, Rio, Brazil
| | Reply from WW:
| | The 88mm VW pistons and cylinders require no machine work to the case or the heads. Only the 94mm cylinders do.
I consulted with Jeff at SC Performance to make sure that the 88mms would be dimensionally identical to the Corvair
motor in height, etc., to make the engine a bolt together kit. If your friend wants to use the 88mm combination, Jeff
will redo the rods to the VW pin size for $50. This is in addition to his regular $200 for rebuilt rods. He also has the
$300 rod set which has polished beams. There are valid reasons to be attracted to both the stock pistons and the 88s.
Neither one changes the fact that the conversion is a very simple one.
| | Subj: New inquizator
| | Date: 8/14/03
Hi William.
Until I saw the Corvair conversion at the Great Plains booth at
AirVenture this year, I thought the AeroVee was the best value on
earth. Now I know that's still true up to 80HP. But the Corvair looks
like a very serious engine up to 120HP. At that HP, I'm wondering about
altitude. Did I read that you're investigating turbo-normalizing the
Corvair? Seems like a Q2 or the new Vision2 could really redefine the
envelope if they could get above weather at speed.
Please let me know what you're up to w/turbo.
| | Joe Tocci, EAA Chapter 2, Fort Wayne, Ind., chairman@smdfund.org
| | Reply from WW:
| | Thank you for your nice e-mail. A few clarifications are in order. Great Plains is the VW outfit run by our friend
Steve Bennett. He has nothing to do with Corvairs. You probably saw the Corvair motor on display at the Contact!
magazine booth, around the corner from Steve. It's easy to get sensory overload at The Big O.
| | My turbo engine is almost ready to run, and we'll post more information on the Web site soon. It's actually
not turbo normalizing, but rather a turbo boost system. And its performance will decay at altitude. Turbo normalizing
requires in-flight adjustable props. My intention is to come up with a very simple system that will retain 100hp at
10,000 feet. A Q2 does not have room under the cowl for a turbo Corvair motor, but you're quite right that a Vision EX is
a good match. We'll keep you posted with a synopsis at the News from The Corvair Authority page on
www.FlyCorvair.com, and also in greater depth in The Corvair Flyer newsletter.
| | Subj: Head Studs
| | Date: 8/13/03
William & Grace,
It was a thrill to meet you at the Contact! magazine booth and to participate in your engine seminar at
Oshkosh. I have not yet contacted Clark's about the dragging OT-10 cam, but will do so tomorrow morning. I need seven (7)
upper studs and two (2) lower studs. All of the case threads look good except for two, which have two partially broken
threads. Would you confirm that ANY sign of broken threads require helicoil? In a couple of months, I will be needing a
distributor rebuild and exhaust stubs.
| | Joseph Snow, Brookville, Ohio, 1flashq@ameritech.net
| | Reply from WW:
| | It was great to meet you at Oshkosh as well. Yes, any sign of broken threads requires a helicoil. Please let us
know if you still need the studs. I have used studs in good condition for $4 each payable by check or money order to
William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802. This includes the S&H in the U.S.
| | Subj: Which Corvair Engines?
| | Date: 8/12/03
Hello,
I attended your seminar at Oshkosh (I was the guy with his young son - in case you remember) and was very interested.
You said there was some group that sold engines as opposed to finding one in a junkyard. What is their Web address?
I just bought a partially completed KR2S kit and although I won't need a motor for a while, I will eventually need one
and I want to start learning about it. When the time comes, I fully intend to take you up on your offer and come to your
place for a class. Anyway, hopefully we can work together in the future. Thanks.
| | Ray, KR2S, ray_pilot@yahoo.com
| | Reply from WW:
| | The Corvair Society of America, www.corvair.org, is who you're looking for. If you do not already have my Conversion Manual, I
highly suggest you get it before acquiring a core motor. Every week, somebody buys the motor first, then tells me they
spent too much money acquiring the wrong motor. All the part numbers, castings and stampings for the correct motors,
along with how we evaluate them, are contained in the Manual. The Manual costs $59 in the U.S., $74 for international
orders, including Canada. You can either send a check or money order payable in U.S. Dollars to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802,
or pay for the Manual by credit card via PayPal at the FlyCorvair.com Online Catalog.
| | Subj: VW 88mm pistons/cylinders
| | Date: 8/11/03
At AirVenture, you mentioned that, given the dearth of forged TRW
pistons, the VW 88mm pistons make an attractive alternative to the forged
stock pistons/cylinders, particularly as regards their lower weight. I can
find no reference to this substitution in the Manual, and would appreciate
it if you could provide me with the details, e.g., part numbers, possible
sources, modifications needed to the sheet metal flashings, etc. Perhaps you
could put this in a mailer as an "addendum" to your Manual, or a column in
your Corvair Flyer newsletter (which I just subscribed to, so I apologize if you've already
done that), or in your Q&A column.
| | Don Lawrence, Los Angeles, Calif., don.lawrence@comcast.net
| | Reply from WW:
| | The TRW pistons are now in stock at Larry's Corvair Parts (phone # in your Conversion Manual). If you're still
interested in the VW pistons and cylinders, the only source that I deal with on these kits is SC Performance. As stated in
the Manual, Bob Sutcliffe developed these conversions. Bob has since sold his business to the very capable Jeff Ballard in
Ventura, Calif. His phone number is 805 644-0006. Specific information about piston and cylinder combinations was covered
in The Corvair Flyer just before you subscribed. New subscribers can obtain all the back issues as a collection for $10 in
the U.S., $15 for international orders, including CANADA, payable only by check or money order for U.S. Dollars to William
Wynne, P.O. Box 290802, Port Orange, FL 32129-0802.
| | My Engine Assembly Video Part II, which will be available next month, has good visual comparisons of all piston/cylinder
combinations for Corvair flight engines. Our friend Merrill Isaacson, aka SkyManta, a video wizard, is in final editing on
these now. He is the production talent behind my other videos, as well. Look for Part II coming soon to the
Online Catalog of Parts Available from The Corvair Authority.
| | Subj: Sonerai Pics
| | Date: 8/10/03
Here are some better pictures of the Sonerai.
About 60 hours now.
| | Glen David, Indiana, propellerprecision@hotmail.com
| | Reply from WW:
| | Congratulations. The aircraft looks excellent. Please send us flight data when you get a chance.
| | Subj: Upside Down Vair
| | Date: 8/9/03
Will the Vair fly inverted? Just in case my bird wanted to go
inverted with me in it that is?
| | John Foreman, Sonex #564, jwf3@daimlerchrysler.com
| | Reply from WW:
| |
There's two ways to fly inverted: pulling positive Gs, such as the top of a loop, and true inverted flight, such as flying upside down in level flight.
A Corvair motor, like all other aircraft engines, can do the first. In a maneuver like this, the engine and systems have no idea
they're inverted in relation to the ground. In the second situation, you need inverted fuel and oil systems. 99% of aircraft engines,
including certified engines, cannot do this. Only aerobatic airplanes like Pitts biplanes and Decathlons have oil systems which
function with the airplane inverted. Having done a small amount of flying like this, I can assure you that the weak link is the pilot. Very few people are qualified to fly outside maneuvers and it takes a lot of training and physical strength to be safe and proficient.
| | Subj: Thrust bearing
| | Date: 8/8/03
I attended your forum at Oshkosh and I must say I was impressed with your enthusiasm and dedication. I am unwinding from my trip as I
expect you are, so I will try to phrase a yes or no question. I raised the question at your forum and you gave a good answer. A little
fog has now settled but I think you said the thrust is taken at the opposite end of the crank from the prop hub. Are there any future
plans to attach the prop to the transmission end?
| | Danny, dannyjoe@insightbb.com
| | Reply from WW:
| | Good to hear from you. We just got back last night. We had a very good trip and really enjoyed sharing what we know with people who can use it. This is what it is all about.
The thrust bearing is on the dirstibutor end of the Corvair. This is at the back bumper in the car, or a firewall in
the plane. The Corvair is and has always been driven off the transmission end of the engine.
| | Subj: Zenair twin, 100ll
| | Date: 8/7/03
I greatly enjoyed my visit to your Web site. The information put forth was very informative and rang of real world
experience. I currently own a '66 Cherokee 180 C, but have the homebuilt bug biting me on the butt. I am trying to
decide what airplane/engine I want to build/use and I appreciate the information. I owned a '65 Corvair Monza as
a teenager and have always regretted selling it. Spent a lot of money at Clark's....
| | I have been waiting on Zenith to develop the 620 twin. They are recommending Jabiru engines but I was thinking either
Suby or Corvair. Your words of wisdom have been helpful. Do you believe that there will be any issues with the engine
when 100LL is phased out in a few years?
Thanks,
| | Ronnie Jones, jones_rl@sbcglobal.net
| | Reply from WW:
| | I spent a lot of time with the Heinz family at Oshkosh. They're having a lot of success with the 601XL and
expect it to be a major player in the pending Sport Pilot category. Their twin might be a lower priority project these
days. I saw the plane in person several years ago, and it was very interesting. I'm not sure it was intended for engines
any heavier than the feathery light Jabiru 80hp.
| | I've operated the Corvair motor on both 100ll and auto gas. It works on either. Specific details of operational
settings for both fuels are contained in my Conversion Manual, available at the Online Catalog.
| | Subj: Zodiac 601 Mount
| | Date: 8/6/03
I saw in your answer to Neil Hulin's e-mail on the "Ask The
Authority!" page that the 601 is one of the best candidates for your upcoming
turbo installation. I am seriously considering matching my future Corvair
engine up with a Zodiac XL. Will your install be on an XL? If not, which
601? Also, tell me more about your "turbo" engine.
Thanks,
| | Gary Kaplan, Zodiac 601, Mount Juliet, Tenn., Kaplan@qualityind.com
| | Reply from WW:
| | Yes, the 601 and the Corvair are a very good match. At Oshkosh, we spent a lot of time with the Heinz family, and they
pointed out that the firewall bolt pattern has been the same on all 601 models for a long time. Thus, my work with Neil Hulin
and others on 601XL projects applies to the previous models as well.
| | The 601 has enough room in the engine compartment to install a turbo without crowding things too much. While it isn't
needed to have good performance on the 601, the turbo is an interesting potential option. The XL has a 180mph Vne. A turbo motor at
medium altitude (8,000-12,000 feet) would really make this airplane scoot. The high Vne is important because Vne is based on true
airspeed, not indicated. If the Vne of the airplane was low, say 140mph, even a modest turbo Corvair motor could exceed this at
altitude.
| | I'll have more information on my turbo testing in the next Corvair Flyer newsletter.
| | Subj: Vacuum pump
| | Date: 8/5/03
I caught your forum at AirVenture and had a question which didn't spring
to mind until the drive home. Anyway, here goes:
Do you know of anyone using an engine driven vacuum pump with a Corvair
powered aircraft?
Thanks for a very informative forum.
| | Bryan Bowlsbey, R70BWB1@wpo.cso.niu.edu
| | Reply from WW:
| | No one that I know of, but many people are using belt driven pumps, and such an installation would be fairly
easy on a Corvair.
Everyone I can think of is using electric gyros.
| | Subj: Stromberg carb
| | Date: 8/4/03
I hope you had a great time at AirVentures 2003!
I need some info on the Stromberg carb. I've got a C-90 carb, but the previous owner says it leaks and no matter
how many rebuild kits he uses, it still leaks. Is there a company that can rebuild the unit for me - and hopefully
do it correctly?
The project may hinge on the carb.
Semper Fi,
| | Dan Edwards, Dragonfly, newtonsrun@msn.com
| | Reply from WW:
| | A conservative estimate from Oshkosh would be 500 planes on the field with this exact carburetor. I did not
notice any of them leaking fuel on the ground. This suggests the chances are excellent that your carb can be made to
behave. Pat Panzera had a good source for needles and seats, but first check to make sure the float height is not
ridiculously high. The rubber tipped needles in these carbs seal very well, but may be incompatible with auto fuel.
A little careful homework here should yield you an excellent carburetor.
| | Subj: Piston skirts
| | Date: 8/3/03
What is the difference in the long skirt TRW pistons and the short skirt? I know the long skirt are 1/2" longer, but
is there that much difference in weight? And would it be ok to use the long skirts? Thank you in advance.
| | Bob Glidden, Manual # 5471, glidden@ccrtc.com
| | Reply from WW:
| |
The long skirts will work as a set. Our application is low rpm. Short skirts are usually aimed at higher rpm applications. The past few years of TRW production have been short skirts and these work fine. But, there was nothing wrong with the previous pistons. They weigh slightly more, but the strength of ARP rod bolts negates this difference. The only issue is that you cannot mix long and short skirts in the same engine.
| | Subj: CH 701
| | Date: 8/2/03
I hope you are well.
I have made my choice: The Corvair and the 701 are the only combo that make any sense in my world. So how can I make
this work? Am I to be left out when hundreds of 701s are in the air with other heavy auto powerplants? Am I missing
something here?
Why have the Gods of aviation vexed me so?
Is there any hope?
Thanks,
| | Steve Harmon, Ohio, iceman2@sbcglobal.net
| | Reply from WW:
| |
Don't think of it as the gods vexing you. Rather, they are giving you an opportunity to show just how devoted to aviation you are. If you won the lottery, bought a turboprop Malibu and had a supermodel wife who also was a pilot, you'd probably fly a lot, but this would prove nothing of your devotion and love. In your situation, where you face adversity, hardship and moments of frustration, all under fiscal constraint, when you eventually triumph, the gods will reward you with many hours of wonderful flights because you proved worthy and only cursed them under your breath in moments of real frustration.
The Heinz family reiterated their position that they do not like engines over 200 pounds on the 701. I seriously doubt that hundreds have flown with motors above this weight. The number is probably close to two dozen or so. Obviously it could be done, but the Heinzes do not encourage it.
| | Subj: Crank case vent
| | Date: 8/1/03
Great site! Thanks for taking the effort needed to supply this great info!
| | I have noticed that you offer a top cover to replace the stock cover with the fan bearing on it.
Do you vent the crank case anywhere? There is a vent on the stock cover is there not? Is a vent needed and if so
where/how is that done with your cover? Thanks in advance.
| | Brandon, brandon@jdhgroup.com
| | Reply from WW:
| | Through much experimentation and testing, I've found the best place to vent the engine is through one of the valve
covers. There is a lot less oil thrown around in the valve cover and a simple Cessna 150 air/oil separator does the
job. This leaves the top cover free to be a simple sheet and greatly simplifies front starter mounting.
| | Subj: Serial number, heads
| | Date: 7/31/03
I cannot find a listing for a Corvair with the serial number
ending in RB. Also, how do I identify types of heads? I have found four
in a wrecking yard, but no engines...they might be usable for aircraft use
and then again they may not be....by the way, I bought manual #5441 from
you...
| | Bob, rwbtoy@fireserve.net
| | Reply from WW:
| | I don't have to check the book on the RB code. It is a 1965-66 164cid, 140hp motor for a high performance Corsa model. I know
this because my land based Corvair is an RB coded 1966 Corsa convertible. Corsas only came with manual transmissions, so you have
no worries about the retarded cam gear which came on 140 motors with auto transmissions.
| | Everything on this motor is good for rebuilding and flying except the heads. The crank is the same 8409 forging, but it
is nitrided, a small plus. Just get a set of '65-69 95 or 110hp heads and you're in business. Note that the old 140 heads should bring
$200 on eBay, more if you have the linkage and carbs. The heads you need are worth half of this. A Corvair car collector would swap
you heads in a heartbeat. Let me know what you find.
| | Subj: Corvair Power 4 Gyro
| | Date: 7/30/03
I want a SMOOTH reliable engine (that does NOT sound like a snowmobile) for a tandem gyro...probably Air Command here in Texas.
Operational weight of ship should be around 1200 lbs.
Subaru is too complex. Do you think Corvair is a realistic solution?
Regards,
| | Charley, thejones@ev1.net
| | Reply from WW:
| | Gyros are not my field of expertise, but I listen to people who know them
well, and I think the combo will work. The Corvair has a double-sided
thrust bearing and is a proven pusher engine (its thrust bearing was
designed to work in this direction). A smaller diameter prop on the motor,
typical of gyros, will be an advantage to the Corvair; it builds HP
faster than prop efficiency declines for a net increase in thrust. It is
simplicity defined, and no aircraft powerplant can compete on a cost
basis. This said, it also has a very nice note to the ear, which leaves
two-stroke and four-cylinder guys a little envious.
Let us know how we can help.
| | Subj: T-51
| | Date: 7/29/03
I was reading about the T-51 produced by Titan Aircraft (Ohio). What are your thoughts on a Corvair for this aircraft?
| | Jim Rogers, Mena, Ariz., docuome@msn.com
| | Reply from WW:
| | I've seen this aircraft in person and it is a beautifully made, light weight, kit. Although its performance may put it in the
Sport Pilot category, it's not likely to be eligible because the category proposal includes only fixed gear airplanes.
| | A while back, I had someone else inquire about putting a Corvair on this airplane. The response from Titan indicated that the aircraft is so specifically engineered for the Rotax engine that it would be very difficult, to say the least, to install other engines. Also, the kit carries a very high price tag. There are a number of other high end kits much more suitable to the Corvair. But, I understand your attraction to this beautiful airplane.
| | Subj: Rings Question
| | Date: 7/28/03
After scouring the Manual for information on rings, I see a moderate endorsement for chrome. In my exchanges with Larry S., I'm
told he also has moly rings as well. Clark's seems to have two different finishes for their rebored cylinders, one of which is
intended for moly. Do you have any input to offer on this issue?
| | Clay "Hoppy" Hopperdietzel, Vision, Tomball, Texas, hoppy@houston.rr.com
| | Reply from WW:
| | I have flown all three major types: cast, chrome and moly. They all work. Most of the motors I build have chrome rings and
standard wall finishes. Cast rings break in very fast, but are not as good at high operating temps. Moly can take a while to
break in, especially if the first hours of operation are a lot of mild ground running. Chrome is sort of middle of the road, and they
have proven themselves in some very harsh tests we have run.
| | Subj: Complete motor
| | Date: 7/27/03
I'm in the process of building a Zodiac 601XL and have heard you may be able to supply a 100-110 HP engine. I live in Alberta, Canada.
Can you pass on some costs, etc.
| | Dave, Zodiac 601XL, Alberta, Canada, dnimigon@telusplanet.net
| | Reply from WW:
| | My primary business is teaching people how to, and assisting them with, building their own engines. You can learn more about
this throughout my www.flycorvair.com Web site. Although it is not my primary focus, I do occasionally provide complete motors.
That story is also on the Web site. Click on complete engines at the FlyCorvair.com Online Catalog. I'm
doing a lot of work to develop the Zodiac 601 installation and make it as easy as possible for 601 builders. I've already made several
motor mounts and have a very accurate jig in which to produce more. There are a few more items to work on specific to the 601
installation, such as a cowling and intake manifold. All of my other products are applicable to a 601. The bible of flying Corvair
motors is my Conversion Manual, and either way you go, it's the starting point where every one of my customers begins.
| | Subj: Correct Corvair engine for aircraft
| | Date: 7/26/03
I am going to go out and scout around the Memphis area for some corvair
engine cores. Are there certain model numbers/years/serial numbers that are
preferable or should be avoided at all costs?
Thanks in advance,
| | Rick Pellicciotti, rick.pellicciotti@fedex.com
| | Reply from WW:
| | You are looking for a 164cid motor, a 1964-69 110 or 95 model. My Conversion Manual, available at the
Online Catalog, has about 10 pages on codes, castings, engine selection and where to find the best engines and what to pay for them.
Every month we get a letter from a guy who was looking at worn out Continentals for $4,500 and then got a "deal" spending
only $900 on a 1962 Corvair, and now that he's got the Corvair, he wants a Conversion Manual. 1962 motors are the wrong year and
they are worth less than $50.
Please send me the letter codes before you buy anything, or you can get the Manual from us. Do not pay any more than
$300 for a motor.
| | Subj: Corvair Conversion Manual, 2002 Edition
| | Date: 7/25/03
I want to buy Corvair Conversion Manual, 2002 Edition. Can I send you cash
through your postal address, and then you send me my copy?
| | And I have a question... This is my first time to even think of building my
own engine, is it kind of possible to make it happen without any help other
than the Conversion Manual?
Sincerely,
| | Mulusew B., doilicho@hotmail.com
| | Reply from WW:
| | A number of first time engine builders have completed Corvair motors by studying my Manual closely and doing the work as
outlined. Keep in mind I encourage builders to e-mail with questions as often as they like. If you are in the U.S., the Manual is
$59, and outside the U.S. there's a $15 international S&H fee for a total of $74 payable in USD to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802. Most of our builders are first time engine builders. I've noticed that first timers
read the directions with greater attention than people with experience who feel they don't have to pay as much attention.
| | Subj: Vision Personal Corvair Cruiser
| | Date: 7/24/03
Hi guys.
Here attached are the photos William took of Morgan.
Enjoy!
Grace Ellen,
FlyCorvair.com Ask The Authority
| | Reply from: Steve Rahm, Vision001@VisionAircraft.com
| | Thanks,
I'll get some of them on the site.
Have a great trip!!
Steve, Vison Personal Cruiser
| | Subj: Prop Spinners, Flying Piet
| | Date: 7/23/03
Thanks for the "Corvair Flyer" in the mail ... it's a great
publication. I'm very interested in the front spinner plate that you come
up with for wood props using the Van's 13" spinner. I'll buy one when you
get them ready!
| | Another Piet is soon to fly on Corvair power... Carl Loar's stock Piet with
a very plain-Jane 164 CID. I'll let you know when he does his first flight
and see if he gets some photos. He's just completed weight & balance so it
won't be long.
| | Oscar Zuniga, San Antonio, Texas, taildrags@hotmail.com, www.flysquirrel.net
| | Reply from WW:
| | Good to hear from you. Please encourage Carl to contact me. A number of guys somehow figure they don't want to bother me
before their first flight. I'd gladly spend an hour on the phone going over a checklist of items with anybody. Although it's all in
the Manual, invariably in conversation I can find something that was left undone.
| | I'll put a post on the FlyCorvair.com Online Catalog when I have the front spinner plates available.
| | Subj: CG
| | Date: 7/22/03
Hope Oshkosh treats you right. Wish I could be there.
Question: Where is the CG located for your engine conversion with the front
starter? Weight should be considered to be right around 225 lbs. for weight
and balance calculations?
Thanks.
| | Oscar Lind, Seattle, Wash., oscar@waggonerguide.com
| | Reply from WW:
| | Depending on a number of small factors, the exact CG location is variable. But, you can get a pretty accurate calculation
figuring the CG to be in line with the #4 sparkplug.
| | 225 represents the engine with the oil in it and the systems to run it. Mounts weigh 5-6 pounds, props are in the 5-10 pound range.
| | Subj: Murhpy Rebel/Corvair
| | Date: 7/21/03
I have been considering a Murphy Rebel as a project, but have been put off a bit by the cost of the 912s and 235s
that they recommend. Now, after reading through your Web site, am I seeing a viable alternative in a Corvair engine?
I have always had very good luck with them (a VW conversion and a Porsche 356 conversion back in the '70s ). I never
had any problems with those engines at all ! I'm not fully versed yet in all the math needed to figure this all out,
but I can build one of those motors. What do you think?
| | Allan Nelson, Seattle, Wash., allan@wattsrv.com
| | Reply from WW:
| | I have always liked the Rebel since it came out 10 or 12 years ago. Your positive experience is typical of
people who have actually worked with Corvair engines. I am sure the Rebel can be suscessfully powered by a Corvair.
| | Subj: Zenair 601 Motor Mount
| | Date: 7/20/03
I'm writing to confirm that you propose to use the 38mm long x 3/8 ID washer
and welded tube firewall attachment depicted in the lower centre of diagram
6-YE-2 that I provided to you. The original engine mount fittings that mate
with the mount attach points have the short bolt for the Jabiru mount. I'm
getting the O-235 mount fittings from Nick @ Zenith and will be installing
those in the next week or so unless you tell me otherwise.
| | Neil Hulin, Zenair 601, Cincinnati, Ohio, nhulin@hotmail.com
| | Reply from WW:
| | I thought I'd post a photograph of your new motor mount. Also in the above photo is my 601
Corvair Motor Mount Jig. As you noted, it shares the same fuselage mounting points as the 235
installation.
The mount weighs 6 pounds on the nose. It turns out, after careful calculation, the Corvair's
prop flange will be 2" ahead of where the 235's is. This is mandated by the fact that the
Corvair is a significantly lighter engine. Because the Corvair has no mags on the back, there
is a generous amount of room in the engine compartment which always makes for an easier
installation. The 601 and the Vision have this space in common, and are the best candidates for
my upcoming turbo installation.
Although I'm very busy, I'm planning on bringing your mount and one other 601 mount to Oshkosh.
If anyone out there would like to bring the second mount home and save on the shipping, send
an e-mail to WilliamTCA@aol.com and let me know.
| | Subj: Starter Kits
| | Date: 7/19/03
Do you still have the starter kits available? If so, what is today's price and do you take PayPal for that like the rest of the stuff?
| | David Voit, Vision Corvair Cruiser, Lodi, Calif., dvoit@pacbell.net
| Reply from WW:
| | We're getting a big batch of stuff ready for Oshkosh and Starter Kits are one of the things we are boxing up.
They will appear on the FlyCorvair.com Online Catalog with a PayPal button in a few days.
I will send you a note as soon as it does. We will have a discount for Corvair Flyer subscribers also. You will see that in
your mailbox in a few days as we mailed out hundreds of copies of the Summer 2003 issue today.
I built a jig for the Vision Corvair Cruiser motor mount two days ago and spent most of the day welding up Cruiser Motor
Mount #1. A very rigid and compact design. The photo above shows three of my motor mount jigs. The orange one is the
Cruiser jig, the green one is my well used KR2-KR2S jig, and the black one is for the Zenair 601. We'll post a photo of the
Cruiser mount on the plane here on the Q&A in a few days.
Be glad to make you a motor mount whenever you're ready. At lunch I sat down and figured out that this was the 17th
different Corvair motor mount design I have done. Some, like my KR-2, have sold more copies than I could remember.
| | Subj: ENGINE HOURS
| | Date: 7/18/03
I WENT THRU THE LOG BOOKS AFTER I GOT BACK AND THEY ADDED UP AS FOLLOWS:
39.5 HOURS TOTAL 18.5 HOURS IN FLIGHT
THANKS FOR ALL THE HOSPITALITY. YOUR FRIEND,
| | BOB LESTER, KR2, FORT LAUDERDALE, FLA., rel111901@aol.com
| | Reply from WW:
| | I got this quick note from Bob Lester and thought I'd share a photo of his Corvair
powered KR2 leaving the runway at Spruce Creek for the 180 mile trip to Boca Raton, Fla.
He had cruised up at 160mph at 6,000 feet. He said the engine was turning a little less
than 3,000 rpm and the fuel burn was around 6 gph.
| | Subj: Turbo Heads
| | Date: 7/17/03
My name is Guy Kelly and I purchased Manual #5608.
I think it was Grace that included a note with it regarding a Guy
Sillikers of Sunny Corner, N.B., Canada. Tell her that he is still alive
at 85 and talks as much as ever. He lives 18 miles west of me.
I have a Corvair that was modified about 25 years ago and never run.
Problem is that it's a '63 turbo according to the block #T0119YR (head #3817287). Heads have
been modified for dual plugs. Original centre plugged (threaded), two
other machined one on each side of centre plug. Excellent workmanship.
It has two distributors: the original and another on pulley end of crank
by way of a bracket.
Could you use these heads, and could I put a set of your 110 heads on this
motor, or should I try to get another engine? Any info would be
apreciated.
Thanks.
| Guy Kelly, Miracmichi City, Canada, mammie@nb.sympatico.ca
| Reply from WW:
| | Guy Sillikers was a big part of Grace's childhood. She enjoyed her months spent
in Canada.
The Conversion Manual contains a lot of good reasons why a 1964-69 engine is more
desirable. But your engine is somewhat of an exception. A '63 turbo motor actually has the
stronger crank material and stronger rods of the 1964-69 motor. The non-turbo 1960-63s did not
have these features. Forged pistons will be a little difficult to find for the 145cid motor.
But cylinder heads are dirt cheap for these engines, and I would highly recommend going back
to a standard set of heads for it. Dual plugs in any Corvair head require a lot of cooling fin
removal right where you need it the most. Let us know how it goes.
| | Subj: Ultravair
| | Date: 7/16/03
Check this out ... what think you?
From: faburns@rockwellcollins.com
We plan on trailering the MiniMax to Oshkosh
the weekend of the 26th of July and parking it in the ultralight area.
Someone will be there with it throughout AirVenture. I will deliver it
there the 26th or 27th then return home until Thursday the 31st, then I
will stay there until the end. I had a lot of help from friends here at
work and they will be there during the week too, but they would prefer it
if I answered any technical questions. This engine has been in the back of
my mind for years and with their help all the pieces finally came together.
| Mary Jones, Experimenter Editor, Oshkosh, Wisc.
| | Reply from WW:
| |
Interesting motor. I'm looking forward to seeing it in person. Fletcher Burns was one of my first customers to buy my Conversion
Manual years ago and build a full Corvair motor. He is a clever guy and still holds the record for lowest price of a Corvair
rebuild and conversion ($1,100). He is quite a scrounger and home machinist. He is an experienced builder - I know he built
at least one plane, a Sonerai II.
I looked at the photo for a few minutes and think he has got all the major points. It appears to have a cam drive VW
oil pump, and I am curious as to what type of regulator he's got. He will have some new type of thrust bearing because the
standard one is in the missing part of the motor. 80 pounds for it actually seems a touch high.
I keep a lot of data on the Corvair, and I think he may well be the first guy to make a 1/3 Vair run. Several people built
a 1/2 Vair inline three in the 1970s, but they are radically out of balance and have poor power to weight.
If he has good solutions to the issues, he will change the landscape of the 1/2 VW world because Corvair stuff is very cheap
and tough as nails by comparison. Power is going to be slightly less, because a 1/3 Corvair is only 900 to 1033cc, but most of
the motors in the class have optimistic power claims.
Technical Note from WW: Mary Jones, my boss at EAA Publications, forwarded the above message and photo to me. I thought people would like
to see the photo. A few days ago, I answered an e-mail and said the Corvair is sort of an all or nothing affair in response to a
guy trying to make a 3 or 4 cylinder engine out of it. Technically, the only reasonable possible combination is the full motor or
an opposed twin like we see in the above photo. We'll get more information at Oshkosh and post it on FlyCorvair.com.
| | Subj: Corvair in STOL aircraft
| | Date: 7/15/03
Several people, as well as myself, are interested in the Corvair engine in the Ragwing Stork, an 80 percent scale reproduction of the Fiesler Storch. There is currently a debate as to how effective the Corvair would be in STOL applications. What is your opinion on the Corvair as an engine in a STOL bird, such as the Stork?
| | Drew, Ragwing Stork
| | Reply from WW:
| | I have received numerous inquiries on this subject. Let me take a few moments to
address the general topic. Please share this with other builders who are considering the same type of installation.
Please note that I've had no direct contact with Roger Mann. One of his builders gave me his phone number, but I've only spoken with his answering machine. Although we travel to airshows nationwide, I've never seen or met Roger. I bring this up because I've had numerous people share comments attributed to Roger that may have lost something in the translation.
The primary concerns of an engine installation are weight and thrust. Although I have not seen what Roger's published
limits are, I can honestly state this from converting many airframes to Corvair power: A standard Corvair engine installation
weighs 35-40 pounds more than a direct drive VW Type I. It is lighter than a Subaru EA-81 with reduction by 25-50 pounds.
It is very close to the same weight as an O-200. Modified Corvairs, such as the 190cid model, are 8 pounds lighter than the
standard conversion. Specially built Corvairs have been made perhaps 10 pounds lighter still. But, the engines I will restrict my
comments to are the standard Corvair models, which 90% of our engine builders are converting. This is the 164cid (2,700cc) electric start motor with no special attempt to lighten it.
On the subject of thrust, there is a great degree of misunderstanding amongst homebuilders. Let me preface my remarks by saying I have a unique background in props, coming from Embry-Riddle Aeronautical University, having been the highest ranking U.S. employee for the esteemed company MT-Propeller, having been a dealer for many other types of props, and having owned, tested and flown many different propellers. I believe very few people making comments on the Internet could match my background on this.
People always quote ridiculously high static thrust numbers and overemphasize the importance of diameter. If you would like a reality check on thrust numbers, Bob Barrows, the highly respected designer of the Bearhawk line of planes, thrust tested dozens of certified airplanes that came through his facility over the years. His Web site lists the exact engine make, model, prop, etc. If you study the data, you'll see that it takes something on the order of a 360cid 200hp Lycoming swinging a 72" diameter metal prop to generate 800 pounds of static thrust. This is why you should be very skeptical when people throw around numbers in the 600-700 pound range associated with 90-100cid engines.
On the subject of diameter, consider this: Cessna built 15,000 150s with O-200s. Many people know that this airplane has an empty weight of 1,050 pounds or more and is a large aircraft by 2-seat homebuilt standards. Yet, these workhorses do all of their work on 69" diameter propellers. Cessna could have chosen any diameter prop they wanted, but 69" is their optimum diameter. It is a myth that there is an advantage to a 72" prop over one which is slightly smaller. If a Cessna 150 would have had even 150 feet per minute more rate of climb with a 72" prop, they would have put one on. The truth is, the engine made greater average thrust over a wide range of airspeeds with the 69" prop that is certified on the plane.
Even if you're expecting much greater than 150 performance from your homebuilt, the point is that an O-200 does a very respectable job of powering an airplane as big as a 150 because it has a highly optimized propeller which stands in contrast to the 72" wives' tale.
It is possible to get very high static thrust numbers by pitching the prop so low that its useful range of airspeeds might be
below 60 mph. A lot of numbers are quoted this way. The same engine and prop diameter, pitched for an 85 to 90mph cruise, will have much lower, perhaps 30% less static thrust, but it will be a useful prop.
We recently thrust tested a 72" Warp Drive on a Corvair without a cowling, and with a cast iron exhaust and big muffler in
place. It pulled 385 pounds of thrust at 2700rpm at a pitch which would yield a cruise speed of 85 or 90mph, with a redline
of 105 or 110. With a cowl and a flight exhaust, it would be 425 pounds or so. This combo would produce good average
thrust over a wide range of airspeeds. In contrast, slow turning fixed pitch props are good performers at a much smaller range
of airspeeds. In a contest from brake release, take off, climb to 500' and level flight to100mph, smart money bets on a setup
like a Corvair or an O-200 over a smaller motor turning a heavily reduced prop.
There is also the issue of cost. I am puzzled by designs which are labeled as "affordable," yet the designer wants you to
use a motor which costs more than the airframe. Most of our customers are spending less than $3,000 total on their motors.
This seems much more in line with the philosophy of plans built airplanes.
Over the years, I have owned a tested a lot of different flight equipment. I do not comment on things I have not worked
with myself. Last week a guy told me that a C-85 produced more thrust than a Corvair. I asked him if he had ever seen a
Corvair turn a prop. His answer was no. I asked if he even owned or operated a C-85. He did not. I own both, and have
built, flown and tested them. Some people are pretty bold about making statements of which they have no firsthand knowledge.
I am giving 5 forums on engines at Oshkosh this year (schedule is posted at News from The Corvair
Authority)
. I will also be spending a lot of time at the Contact! magazine Booth 3109. I encourage anyone to come by and talk about motors and props. Be glad to share what I know.
| | Subj: 601/Corvair Progress Report
| | Date: 7/15/03
I have purchased a 1968 95 HP (TA) engine, 164 CID and it has the correct heads on it, 3878569 with quench area.
The interesting thing is that the engine has a "Torsional Vibration Dampener" on it, and I was told by the seller that the engine was never worked on to the degree that something like that would have been replaced. He claimed that the vibration dampener was stock because the car had air conditioning right from the factory(?).
I will be checking the Web site frequently as your development of the "firewall forward" stuff for the CH601 may be where I'm headed.
Thanks again for being "in the arena."
| Gerry Scampoli, Zenith 601, Manual # 5600, GScampoli@HomeMarketFoods.com
| Reply from WW:
| | The last three years of Corvair production are famous for having a lot of minute
variations. Years ago, I purchased a completely original RD code 110 engined 1967 Monza coupe.
It had no harmonic balancer. Your experience may be similar to this. In any case, it doesn't
matter because we know what we need for flying.
I am bringing Neil Hulin's 601/Corvair motor mount with us to Oshkosh. I have several
forums there (see the News from The Corvair Authority page for the full schedule), but
I'll leave the engine mount on display at the Contact! magazine booth. I built a very stout
and accurate jig for it. I am working from complete sets of factory drawings supplied by Neil,
and the mount
should bolt right up. It has correct offset, inclination and CG information for the Corvair.
| | Subj: PFA Corvairs
| | Date: 7/13/03
We had a very successful day with our PFA Chief Engineer who was impressed and 'excited' by the Corvair!
It was a very popular exhibit on our Pietenpol Club stand!
You may be getting an enquiry from a fellow builder David Hanchet ref shipping a core over for him...
Regards.
| Paul J. Shenton, Pietenpol, England
| | Reply from WW:
| | Glad to hear things are progressing in England with the PFA. Some people on this side of the pond often parrot the story that introducing new engines to the PFA is impossible. Your efforts on behalf of the Corvair obviously stand in contradiction to this. As always, progress in aviation is made by people in The Arena. Congratulations on your efforts so far.
| | Subj: Forged pistons
| | Date: 7/12/03
Like many others, I’m having difficulty finding forged pistons. My machinist has bored my cylinders and they cleaned up at
.060. Do you have or know anyone who might have a set of .060 forged pistons for sale at a reasonable price?
Thanks,
| | John Krumrine, Zodiac 601XL, College Park, Penn., jqk4@psu.edu
| | Reply from WW:
| | Please note that forged TRW pistons are back in production and the first batch will be
on the shelf at Larry's Corvair Parts (phone number in my Corvair Conversion Manual) July 25. They are priced at $269 a set,
and Larry says they will be available in all sizes. He is taking advance orders at this point.
When you contact Larry's, please tell them you're an aircraft builder, as we're trying to get
an idea of how high the percentage of forged piston buyers are aircraft guys.
| | Subj: Corvair for Jodel D-18
| | Date: 7/11/03
I read and re-read all your very informative info.
Dad was an A&P, and automotive instructor for trade schools and community schools, so reading and looking at your
information to me is secound nature. ( Plenty of dining room conversations revolving around engines and transmisions! lol)
And about 200 tranys rebuilt and 3 VW engines rebuilt under my belt, so I can imagine the time and work you have put into
the Corvair.
I have owned one certified plane (PA-16) w/O-235 engine and now have finally decided on building the Jodel D-18 as
it's my estimate that it may be a strong candidate for the Corvair installation.
Weight and balance seem to work out nicely.
Do you have any personal information on this? Or comments?
Thank you for all your efforts.
| | Michael Pitman, Portland, Oregon
| | Reply from WW:
| |
Jodels are well respected designs. For the models aimed at the 100hp category, it is a natural match. Perhaps the only drawback to a Jodel is its somewhat large one-piece spar, which presents a space challenge to some people building. But, its good qualities certainly outweigh minor drawbacks. A gentleman in our EAA chapter has one and raves about it. It certainly appears to be a nice flying plane.
The Jodel's proven nature stands in contrast to a lot of new designs that crop up which
generate a lot of interest, but to people working in the industry remain unproven. All
aircraft, from the Wright Flyer to the 747, were unproven designs in the beginning.
But the work of flight proving a design is the realm of the professional, not the sport pilot.
There are actually a handful of new designs every year which are marketed to unsuspecting people
who assume that the airplane is structurally sound and has been wrung out. Sadly,
this is not always true. New builders have occasionally wasted a lot of time building an airplane
which has never been reviewed in a magazine, flown to Oshkosh, taken on a significant flight,
etc. For those who are new to aviation and building and are a low time pilot, I encourage you to build successful flight proven
designs such as the Jodel.
| | Subj: Oil cooler
| | Date: 7/10/03
Hope you remember me from Preston, Minn.; the can of Cherry Grove dirt?
My Piet is ready to go, at least so I thought. I was doing high speed taxi and the oil temp
rose to 280 degrees! I got out your Manual and ordered a folded fin cooler. Is this the right
thing to do or should I install a remote cooler? My present oil cooler is an 8 fin. Also,
where should the oil temp probe be located? It looks like mine is in the rear of the engine
just above the oil pan. Hope to see you at Broadhead. Thanks.
| Dave Mensink, Pietenpol, Preston, Minn., dmensink@earthlink.net
| Reply from WW:
| | We remember your hospitality well, and we still have our can of Cherry Grove dirt on the kitchen counter.
A folded fin or twelve plate will be superior to the 8-plate by a mile. 280 degrees is too high. The cooler should make a difference. Also note that twice in the past year we've had two customer oil temp problems turn out to be faulty gauges reading high. Your Pietenpol style setup with the blower fan is particularly resistant to high temps. Please note there's several little sheet metal pieces that mate with the top shroud to ensure the air's directed over the cooler.
See you at Brodhead.
| | Subj: Dual Points Distributor
| | Date: 7/9/03
I purchased the Conversion Manual from you a few months ago and I have since noticed
that there is a Mallory dual points distributor from Clark's. Is this similar to what you do when you rebuild one?
| Scott Laughlin, cookwithgas@hotmail.com
| Reply from WW:
| | The Mallory is aimed at high rpm racing. It has only three lobes and each set of points runs half the motor.
The idea was that the points wouldn't get worked as hard if the motor was spun to 7,000rpm.
My setup uses a six-lobed cam to create redundant ignition. Since we turn less rpm than the car did, we have no problem with
point life.
| | Subj: The New Conversion
| | Date: 7/8/03
We finally got our engine running. It may need some more tweaking, but is not broken in by any
means. We had a terrible time starting it (hand prop) until we had about an hour of ground
running on it. The problem seemed to be the terrible strong drag on the cast Grant rings. It
was so hard you couldn't tell when you were coming up on compression, but that is getting a
lot better with every run. We are using the breakerless distributor set about 12 degrees
initial and haven't gotten enough courage to try to see what kind of advance we are getting at
full throttle. It turns 3,000rpm static and a little over on takeoff. First flight was today
(about 15 minutes) and so will have to get some more time to get the readings finalized. Rich
reported the airspeed read 85 at level flight and the GPS said 71mph over the ground. We think
our oil temp is a little high and will be working on lowering it some. --240 degrees "F" at
the filter. I don't think we have enough outlet on the bottom cowl so will open that several
more square inches next. The John Deere Dynamo works great so far. We are not electrical
engineers so don't know how long the "Goldwing Motorcycle" battery will take the 14.2 volts. I
think it will depend on the amperage more than the voltage??
We aren't going to make the Brodhead Pietenpol Fly-In. I (Ray) am an early Hatz builder,
Serial No.#6 1981. Although I don't own it anymore, I'm pledged to attend the 35th year Hatz
Reunion at Merrill, Wisc., that same weekend. I will attend the Grass Roots affair at
Brodhead in September. Maybe Rich will fly the Pietenpol over there for his only cross country
this summer.
It has been a long and frustrating task rebuilding the Corvair but I hope it will prove to
be worth the effort. The biggest problem we found was the baffling and the remote mount filter
and cooler.
Well as my old TWA captain buddy used to say, "Keep the oily side down and the shiny
side up" and we will hope to see you some day at a Sport Plane Fly-In.
| Richard & Ray Hill, Pietenpol, raydot@pcpartner.net
| Reply from WW:
| | Congratulations.
It will get much looser, as I am sure you know. 240 is not too high if this is before the
cooler. It will drop 20 or 30 degrees
when the cylinder friction goes down. Generally this takes 2 to 5 hours.
14.2 should be fine; check the water in the battery frequently, but this should not be too
high.
It may have been work, but if building and flying planes was easy, then everyone would do
it. I am sure you know it was worth the effort.
| | Subj: Metal Props
| | Date: 7/7/03
My name is Samuel and I'm building a Midget Mustang (MIA) from kit.
The plane is designed for engines from C-85 CFJ with prop diameter of 58" up to 150hp engines as
Mustang Aeronautics (maker of kit) publish.
The Corvair engine is a good choice for me and I would like to know if it accepts metal propellers as well?
Many thanks.
| Sam Tor, Midget Mustang, Israel, torsh@zahav.net.il
| Reply from WW:
| A good friend of mine has an 80% complete Midget Mustang. I just made a Corvair to MM mount for it two
weeks ago. A picture of it is below. My friend has owned one before and thinks they are great planes.
I do not aprove of metal props on Corvairs. Most people no longer fly fixed pitch metal props on things like Midget
Mustangs because the speed of the plane requires the prop be pitched out of limits. People have been killed doing this, so
the general thought is that wood props are the way to go. (Popular fast homebuilts like 360
powered RVs have special metal props made for them.)
| | Subj: Ballast Resistor
| | Date: 7/6/03
Where does the ballast resistor fit into the ignition system?
| | Fish Fischer, Dragonfly, Warrenton, Ore., fishhole@pacifier.com
| | Reply from WW:
| | A ballast resistor's purpose is to lower the 12 volt system voltage to the coil for continuous operation. Thus, it is in
line, in the 12 volt line, to the positive side of the coil.
| | Subj: Stromberg Carb
| | Date: 7/5/03
I have a question about the Stromberg carb. I have found one and the guy who is rebuilding it for me says that he is installing the
large needle valve and that he has a venturi that looks as if it has been polished (?) and maybe about 40mm. My question is: Does
this sound good for our application? I am thinking with the bigger venturi maybe I can feed the motor more fuel, i.e. more power.
Yes -No? He says he is also setting it up for running with a fuel pump 2-4psi. I believe your Conversion Manual states that the stock
pump runs about 5psi, so I will have to also run a regulator. If I am running a boost pump (Zodiac CH601 XL), will the stock fuel
pump handle the extra pressure or should I run a fuel line from the boost pump to the carb bypassing the stock pump? Thanks for
any help.
| Doug Cowlthorp, Zodiac CH601 XL, Winnipeg, Canada, thorp@escape.ca
| Reply from WW:
| |
If the venturi is actually 40mm, it's probably too big for a Corvair. The Corvair will run surprisingly well on carbs as small as 32mm, and in some cases we use 35s. But, if you do the math, a 40mm carb has a drastic increase in area that the Corvair does not need. Too big a carburetor sacrifices some desirable characteristics, such as accurate metering at WOT. A Corvair fuel pump is in the 5-6psi range. I have seen it run being fed by an electric fuel pump, but test your pump carefully. Many of them produce excessively high pressure and you would need a regulator. If you're interested in using the stock pump, perhaps you should look at an MA3 carb, as they handle fuel pressure naturally and come equipped with 35mm venturis.
| | Subj: Corvair Powered SL-2 Project
| | Date: 7/4/03
I sent you an e-mail a couple weeks ago asking for
Corvair engine information. Thank you for the reply. I
will be getting the Conversion Manual and Corvair Flyer newsletter soon. I put
together a Web site, http://geocities.com/davedpilot,
to show what I've been working on. I will add more
content as time allows. Check it out and link to it if
you want. I put a link to flycorvair.com, if you don't
mind.
Thanks.
| | Dave Goolsby, davedpilot@yahoo.com
| | Reply from WW:
| | Let me first say that you're an awesome CAD draftsman. The graphics are first rate and very eye pleasing. Secondly, your aircraft design has a very aesthetically pleasing shape to it. I'll be interested to see how it progresses for you. I have a number of people, both amateurs and professionals, working on designs specifically for the Corvair engine. The engine's affordable nature has certainly sparked a lot of creative interest. I showed your design to several people, and one relatively green guy said "Hey, that looks like a .... " so and so. About simultaneously, the experienced guys said, "Yes, all good aircraft designs bear a resemblance to another successful design." If anybody brings this up about your design, make sure you use the response of the professionals.
| | Subj: 12-Cylinder Corvair
| | Date: 7/3/03
Could two Corvair engines be mounted in tandem or top and bottom to drive one prop and produce 200 + HP? One carb
to feed both engines --12 cylinders !!!??? How is that for a WILD idea?
| Lynn Clark, Chappell, Neb., ilflyaw@megavision.com
| Reply from WW:
| |
I'm usually entertained by challenging ideas. I hear stories that many people in the business are always complaining about customers who have off the wall ideas. While we get the occasional question about putting a Corvair motor in a Lancair IV, for the most part, questions that are like yours are simply creative people exercising their imagination and I applaud this. I am certainly guilty of enjoying many a late night in the hangar with my mechanical friends and musing over such ideas. Anyone who doesn't enjoy this process is missing some of the fun. Keep in mind, though, actually building and flying some of these may be hazardous to your health. 200hp of Corvair engines would probably weigh 440 pounds. Even if they shared some items - starter, carb - it would still weigh 400 pounds for 200hp. Compared to many other automotive conversions which claim to produce 200hp, this would actually weigh less than things with radiators and cast iron blocks. As a reality check, a 360cid 200hp Lycoming has an all up weight in the neighborhood of 330 pounds. Keep up the imagineering.
| | Subj: Corvair Engines on eBay
| | Date: 7/2/03
I came to your web-site from Vision Plane. Both sites gave me a push of
adrenaline when thinking that I may no longer only dream of but really fly my
plane! Congratulations for your perseverance and contribution to "everybody's
flying pocket."
Lately I've noticed that someone is selling several Corvair engines on the
eBay. May I please have your advice about their feasibility to be
overhauled and transformed into flying engines?
Many thanks in advance.
| | Sasha, sasha47@kornet.net
| | Reply from WW:
| | Thank you for your nice comments about my work. Vision aircraft are the products of my friend Steve Rahm. He is very devoted to the concept of keeping aviation simple and reasonably affordable, as am I.
My Corvair Conversion Manual contains all the details on engine selection, head numbers,
how to identify the parts, etc. It's available for $59 in the U.S. and $74 for international
orders by credit card at the FlyCorvair.com Online Catalog or by check or money
order in U.S. dollars payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802.
But, basically you're looking for a 1964-69 95 or 110hp motor. Either one is a good start on building a 100hp aircraft conversion.
| | Subj: Carb location
| | Date: 7/1/03
I've read your Manual cover to cover and find it very enlightening. It's
refreshing to read about the real world instead of a lot of ill-informed
arcticles from people who haven't gotten their hands dirty. Thank you.
Question: How difficult would it be to move the carb forward to about
mid-engine? The design I most want to build has a lot of structure under the
back third or so of the O-200 powering it. I'd much rather power this
aircraft with a Corvair. Do you have experience with the carb in other
positions under the engine? Are you still as impressed with the Aerocarb?
Many thanks.
| Oscar Lind, Seattle, Wash., oscar@waggonerguide.com
| Reply from WW:
| | Thank you for the nice comments. The Corvair is not particularly sensitive to
carburetor location. It makes its horsepower the old fashioned way, by cubic inches. I
have tested countless carburetor locations, sizes and styles. The engine is a good performer
with virtually any system that visually makes sense. The two features that are most
counterintuitive are that the length of the tubing does not affect the horsepower output of
the engine and that the engine will make its power on a smaller carburetor than would be
required for the same power output in an engine with less cylinders. Our friend
Steve Makish (see Steve Makish's Corvair Powered KR2 on FlyCorvair.com)
is currently flying a Corvair powered KR with an Ellison throttle body in much the same
location as you describe. The airplane has well over 100 hours of Corvair powered flight on it.
| | Subj: RANS S-6 COYOTE
| | Date: 6/30/03
I've been spending much time on your Web site and am very interested in your
Corvair engine. Do you think that it would be compatible with a Rans S-6S
Coyote? The company recommends/sells any Rotax between the 582 to the 912S
for the plane. The Rotax is about 40 lighter than the Corvair and that is
without the electric starter. Any thoughts on this issue would be greatly
appreciated.
Thanks.
| Steve Hart, Bremerton, Wash., harts@psns.navy.mil
| Reply from WW:
| | I have not studied the Rans designs closely as they rarely fly with
alternative engines. A good starting point with an airframe designer is to ask him whether or
not the particular design could be flown with an O-200. Almost all airplane designers are
familiar with the O-200's size, weight and power characteristics, which are closely matched to the Corvair's. In my experience, many airplane designers, while masters of their art, are not well versed
in alternative engines. Although we think of the Corvair as being very popular, many airframe
designers do not have direct experience with them and certainly many of their opinions are
based on old wives' tales about the engine. Phrasing the question about an O-200 will
generally yield useful technical data without addressing an airframe designer's limited
Corvair exposure.
About once a week we get a letter from an airplane builder who says his airframe
designer states that Corvair motors are either too heavy, don't make enough power, etc. In
many cases, these designers could not answer fundamental questions such as how many cubic
inches is a Corvair, how much does it weigh, or basically, have you ever seen one turn a
propeller before. The majority of respected designers, when asked a question about a subject
they're not well versed in, will simply say "I don't know much about it." Sometimes we deal with the reverse.
| | Subj: Corvair-powered Junior Ace question
| | Date: 6/29/03
I'm deciding whether to build a Piet or a Junior Ace in my garage. If I
were to use a Corvair engine in a Junior Ace, including an electric
starter, could I safely keep the weight under the LSA limit of 1232
pounds?
| | Mark Hodgson, mhodgson@bu.edu
| | Reply from WW:
| | Either airplane, Piet or Junior Ace, can be built with a full electric start Corvair and still retain an excellent useful load. There are many examples of Corvair-powered Pietenpols. If you'd like an example of a Corvair-powered Junior Ace, check out Jake Jaks' Web site, http://home.att.net/~jrjaks/index.html. Jake was the first graduate of Corvair College. Either of these aircraft are excellent performers on a Corvair motor, far exceeding their original performance on engines like 65 and 75hp Continentals which are now unaffordable, and never offered such conveniences as full electric starting.
| | Subj: Corvair car carbs
| | Date: 6/28/03
I just happened to take a look at the Pietenpol and
ended looking at your Web site on converting the
Corvair engine for aircraft use. I have only one
question: Can you use the original carb (the one used
in the car) for aircraft use?
Thanks.
| Dean, deanvoisine@yahoo.com
| Reply from WW:
| | The Corvair cars have 2 or 4 downdraft carbs (depending on the model) bolted directly to the head. They are 4" tall
and would be impossible to streamline into a cowl.
| | Subj: Carb, safety shaft, prop
| | Date: 6/27/03
I have started conversion of a Corvair engine for a Zodiac CH601 HD project using your Manual and info from your Q & A on your Web site.
I am hoping for about 110hp using the OT-10 cam, forged pistions .060 overbore (because .010 not available) and other mods
according to your Manual. I would like to know whether a Stromberg NAS-3 with 32mm venturi is large enough to produce 110 hp.
I have contacted a local machinist to make a safety shaft. He would like to know whether the two grooves are necessary
(one is 1" from one end, the other is 2" from other end). Can these grooves be eliminated?
Would a 2-blade, 68" Warp Drive prop, #N6515 be suitable for my project?
| Bob Duns, Zodiac CH601 HD, Manual #5053, rduns@sasktel.net
| Reply from WW:
| | Getting a full 110hp out of a standard displacement Corvair involves winding the motor up to approximately 3200rpm. This will not harm the motor at all. The two considerations you mention are prop diameter and carb venturi. In the interest of more power, I would suggest the larger 1 3/8" Stromberg venturi. The smaller one is effectively limited to 85 or 90hp on a Corvair. To wind the motor to 3200rpm, I believe a 66" two-blade Warp Drive would be a better bet than a 68". Keep in mind that the Warp Drive is solid carbon fiber and can be trimmed to any desired diameter. Thus, a prop ordered as a 68" could easily be trimmed with a hacksaw.
The two grooves on the safety shaft are to provide a clean end to the threading. This way, the shaft butts squarely on the end of the crank. It also works to reduce the stress rising tendency of the end of a thread. Over the years, we've had absolutely zero problems here, but the groove style in the drawing is standard engineering practice.
| | Subj: Corvair for Zenith CH 701?
| | Date: 6/26/03
I have been looking at the Zenith 701 design. While it is aesthetically challenged, it has its advantages. I noticed it has
been built with many different engine installations. Do you know if one has been built with a Corvair conversion?
What are your thoughts on this application?
Thanks in advance,
| | Karl F. Counts, Karl@CountsFamily.com
| | Reply from WW:
| | I recently exchanged e-mail with Sebastien Heinz, in which he reiterated his family's position
that the best engines for the 701 are the lightest ones, although their Web site and advertising
shows engines that are heavier than the Corvair, like the O-200 and EA-81s with reductions. If
the airframe will fly with the weight of these engines, the airplane will certainly fly with a
Corvair. Sebastian just feels that it's better off with the lightest motor you can get.
| | Subj: Ignition
| | Date: 6/25/03
Using your dual points distributor, one must need to employ an "automatic coil selector," since both sets of points use the same
plugs. If one coil shorts (the old shorting tach question) does the coil selector default to that set of points?
| | John Sandt, Avid or Kitfox, Calif., josandt@netzero.com
| | Reply from WW:
| | The coil selector has no moving parts. It functions as two diodes. What is selecting which ignition system you're on is a panel mounted switch providing 12volt power to the positive side of either your A or B coil. Thus, you have to manually switch it to the other side. Although you can run both at the same time, it is not recommended by the manufacturer. On all installations, I recommend this switch be put in a position where you can change it without removing your hand from the stick or the throttle.
| | Subj: Corvair in Brazil
| | Date: 6/24/03
Thanx for your response. I saw Mr Tadeu's message at your site and contacted
him, congratulating him on finding a Corvair (alive!) here in Brazil, which
is almost impossible. Unfortunately he found only one!
Time is not really a concern, as I didn't really start my KR2S yet.
FYI it's quite possible that I will show-up at Oshkosh this year and them
we could talk directly.
By the way, I was at Sun 'n Fun and watched your forum.
Best Regards,
| Oswaldo, KR2S, Rio de Janeiro, Brazil, oswaldo10@globo.com
| Reply from WW:
| | If an engine does not turn up by the time you need one, I certainly can arrange an export if it's required. I have
shipped engines to England and Australia. I have great respect for anybody who would build an airplane under what have to be
more challenging circumstances than anyone would face within the United States. Most U.S. guys don't stop to realize how lucky we are.
Thank you for coming to one of my forums at Sun 'N Fun. Although there's always a crowd around, I am very much a people person, and under these circumstances, especially if we haven't had the chance to meet before, I encourage anyone to introduce themselves and spend some time with us. I attend these events from coast to coast specifically to meet people in person. The forum is just a way of starting the discussion. I'm looking forward to meeting you and many other friends, new and old, at Oshkosh this year.
| | Subj: Avid Mark IV and Corvair
| | Date: 6/23/03
I have an Avid Mark IV..is the Corvair well suited for this aircraft? I now have a Rotax 582 and am considering a VW...
Corvair...or a Subaru... Thanks,
| | Mike Allman, Avid Mark IV, Knoxville, Tenn., MCALLMAN@aol.com
| | Reply from WW:
| | We have a couple guys working on Corvair installations on their own Avids. On the Mark IV, it's important to have the heavy duty model for any 4-stroke installation. The Corvair motor falls between the VW and the Subaru for installed weight. A typical Corvair is approximately 35lbs. heavier installed than a Type I VW. With a conversion to VW cylinders, the weight difference on the Corvair would shrink to 26-28 lbs. And of course, the Corvair engine would have 900cc+ (about 55cid) more displacement. The Subaru EA-81, with its smallish 1800cc displacement, has to be worked very hard through a belt reduction to be in the same power league as the standard Corvair engine. In recent years, builders have removed several EA-81 installations and replaced them in the same aircraft with Corvair power plants. In all instances, the Corvair was substantially lighter. Although the EA-81's base motor may be lighter than the Corvair, its proponents frequently tout the engine's weight without the hoses, water, radiator, thermostats, etc., that are required to go flying. I don't know why this practice is tolerated, but it's silly. In a typical case, a standard Corvair motor with iron cylinders in a direct drive format will be 35-40 lbs. lighter than an EA-81 with its required PSRU ready to fly.
| | Subj: Vari-Eze
| | Date: 6/22/03
Can you give me a source for information and your opinion about using the Corvair engine to power a Vari-Eze?
Thank you.
| Del Ralston, N770DY, drals1234@adelphia.net
| Reply from WW:
| | We have several people working on VariEz installations of Corvair motors, but I'm not aware of anyone currently flying this combination. I did a design study and built a motor mount for my friend Arnold Holmes' VariEz. He has since sold the project to a group of builders in a Minnesota EAA chapter. Arnold and his father are planning on moving to a grass strip, which would not be favorable for a VariEz. I intend to stay in touch with the new owners and will keep you posted on the installation.
| | Subj: Corvair engines (of course!)
| | Date: 6/21/03
I am in receipt of your wonderful Manual, I've read it through at least three times and I want to thank you for its simplicity and real educational value. Thank you.
| | I've started to look for an engine and I've found that people who have the engines we want DO NOT
ADVERTISE THEM! They'll advertise a turbo or a 140 HP, but not a 110 HP. If you contact someone who is selling a 140
HP and ask, he'll probably have just what we need, but he didn't think it had much value, so he didn't include it in the ad.
There's even one advertisment on e-bay right now that is for two 140 HP engines; if you buy the two 140s, he'll throw in a 110 HP engine for free! Ironic, isn't it! The real stickler in all this is the cost of shipping an engine. I can't seem to find one local enough to just drive there and pick it up. Does Clark's sell used engines? I'm in Massachusetts.
| | You should have my order for the Quarterly Newsletter by now. I am looking forward to having a rewarding time
building my Corvair engine and deciding on the correct aircraft to build to complement it.
Thanks again,
| Gerald N. Scampoli, Mass., GScampoli@HomeMarketFoods.com
| Reply from WW:
| | That is a very keen observation you've made on 110s. A 180 turbo or 140hp Corvair motor is worth five to 10 times what a 110 or 95 is. So, your observation may be even more common than you suspect. Keep running down leads in your own area. Massachusetts has a reputation for being rich with Corvairs. Clark's does sell whole engines when they have them, and they have a huge selection of used parts also.
| | Subj: Corvair Cranks
| | Date: 6/20/03
I'm wondering what your process is for adressing crankshafts. Do
you automatically do the 10/10, do you expect it to be done before you
get it, or do you handle it on a case by case basis subject to
inspection? Are you doing the regrinds, or sending that out?
| | Another question is: Is there an advantage to regrinding an in-spec
crank just to clean it up, or is there a downside to the regrind which
makes avoiding it desirable?
| | What exactly are the options here? I suppose I could have it reground
locally, and then send it your way for safety shaft modifications, or
perhaps the other way around would work too.
| | My thought is, if you are outsourcing the machine-shop work, there is
probably not a lot of use in sending you the raw crank, causing you to
have to do the legwork to send it somewhere else. Conversely, I want
your hands involved in the safety shaft because I want somebody who
knows how it's supposed to look when it's done. Thoughts?
| | Clay "Hoppy" Hopperdietzel, Vision, Tomball, Texas, hoppy@houston.rr.com
| | Reply from WW:
| | The grinding and threading are handled for me by two craftsmen who have done virtually all of them since 1997.
(I never publicly identify who these guys are because they are small businessmen with families and I would never jeapordize
their situations in the litigation prone world of aviation. In all of my years in business, I have never been involved in a lawsuit,
but I would not have these fine craftsmen be made nervous by unnecessary publicity.) These guys are very, very good, but the
jobs they tackle on the Corvair stuff would not challenge any competent guy in your area. To address the safety shaft issue,
I suggest you purchase one from me ($66 for U.S. orders, $81 for international orders, by check or money order payable to
William Wynne, P.O. Box 290802, Port
Orange, FL 32129-0802 or by credit card at the FlyCorvair.com Online Catalog) so the machinist can have it in hand when he threads the crank.
If your crank is within factory limits, then it is perfectly acceptable to fly it. Most machine shop guys agree that engines operated continuously at high output benefit from looser tolerances on the bearings.
| | Subj: Possible engine for Fybaby Project?
| | Date: 6/19/03
I'm looking into getting a partially-done Flybaby project. I'm a newbie,
and have never done any home-built projects before.
The plane comes with a Continental O-290G, which I'm told is too heavy
for the plane. A friend gave me your Web site, and I'm very intrigued.
Would a Corvair engine be as light or lighter than a Continental O-200/
85 Hp? The cheaper aspect of the engine certainly is appealing -
especially to my limited pocketbook. The 6 cylinders seemingly would
make it a smooth-running engine.
Has anyone else used it for a Flybaby before? Any info or advice would
be greatly appreciated.
Thank you,
| | Jeff Patnaude, Snellville, Georgia, EAA 690, patnaude@comcast.net
| | Reply from WW:
| | Good to hear from you. As you probably know, the Flybaby was designed in the early 1960s by Peter Bowers, one
of the aviation greats of all time. It is a sad note that Peter Bowers passed last month. Aviation as we know it is far richer
because of Peter Bowers' writing and photography. His aviation photography collection and his knowledge of light aircraft are
unmatched. We can only hope that his collected works will be made available to the public via a university or EAA
headquarters. I am sure we will see excellent coverage on the life and times of Mr. Bowers in a coming issue of Sport
Aviation.
| | As for the Flybaby, it's a great design and was built in large numbers. You are quite correct that an O-290G is the wrong motor for it. It was intended to be powered by one of the small Continentals, 65-100hp. Just a note: An O-200 is 200cid and 100hp at 2750rpm; a C-85 is 85hp, 188cid, and rated at 2575rpm. The Corvair motor in its standard configuration would make an excellent motor for the Flybaby. The engine's low cost and plans built nature complement the Flybaby philosophy perfectly. Electric start would make a nice touch to make the plane easy to operate. In this configuration, it will weigh about the same as an O-200, but be far smoother. And of course, it will not require raiding your Swiss bank account.
| | Additional good news is that your O-290G, if it was converted correctly to an aircraft engine, is worth far more than you will spend to completely overhaul and convert a Corvair motor to flight ready status. Even a worn out O-290 will bring far more money than the wonderfully inexpensive Corvair will cost you. Welcome to the wonderful world of Corvair economics - initially hard to believe, but true.
| | Subj: Starter mount
| | Date: 6/18/03
I have a question about the new front starter mount mentioned in the Spring 2003 Corvair Flyer newsletter. I noticed in the picture that the left
hand mount appears to have a tab welded to it
, and the "link" is attached (bolted) to it. In the drawings on Page 9, you show a 3/8s
bolt welded to the 3/4 square tubing. I am assuming that the 3/8 bolt goes into the starter mounting hole. My question is which of
these two methods is the most recent? They both appear to be a
much better idea than the welded 1/4 mount with the hole, from the
Conversion M
anual. Also, I would think that the mount with the 3/8 bolt would drop the starter an
additional inch or so - is this right?
Regards,
| Doug Cowlthorp, CH601XL, Winnipeg Mb., Canada, thorp@escape.ca
| Reply from WW:
| The first generation of front starters are characterized by an aluminum angle bracket
and the method shown in my Conversion Manual shows how to fabricate your own aluminum bracket. While this worked and flew many hours, with examples of it flying as far away as Australia, this is now being superseded by the mount characterized with the welded square tubing and studs as you mentioned. Just so we have terminology so everyone can be on the same page, we'll refer from now on to the early style as the original front starter, and the new model will be referred to as the low profile front starter.
You have very sharp eyes, and are a good observer. The pictures above, below and on the
back of The Corvair Flyer are of the prototype of the low profile starter. The drawing in The Flyer
is how
we're actually shipping the parts. It does have a 3/8" stud in place of the tab and bolt, and is a detail improvement.
The low profile starter is a height reduction of about 1". More importantly, it's easier to fabricate and is adjustable in height, and therefore more forgiving of each individual assembly. It's slightly lighter also. I've studied the whole system in great detail, and I'm now very satisfied with it. Accordingly, I've had batches of the parts made up so I can offer kits. It's going to be the only starter system I'm putting on all the motors I build from now on.
| | Subj: Kolb MKIII
| | Date: 6/17/03
I have been flying a Kolb MKIII for several years, and have owned
several Corvairs since I was 20 years old (a long time ago).
My airstrip is only 750' long, and the MKIII takes off MUCH quicker with a
68" prop instead of a 64" prop. I assume that the only way to swing that
big a prop with a Corvair engine is by adding a reduction drive, is this
feasible?
Thank you.
| Richard Pike, rwpike@charter.net
| Reply from WW:
| |
I recently have thrust tested propellers as large as 72" with succesful results on direct drive Corvair engines. Although I
personally prefer slightly smaller props, even on the slowest of airframes, I went out of my way to accurately thrust test a
Warp Drive prop of this diameter in order to provide factual data for my customers on this.
(This thrust test is included on my latest video, Corvair Engine Assembly Part I, available for $29 by check or money order
payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card at the
FlyCorvair.com Online Catalog .)
There is a bit of a misconception among homebuilders about the upper rpm limits of certain prop diameters.
Keep in mind there are certified props for 2,700rpm Lycomings as large as 86" in diameter, which of course are run
direct drive on aircraft with forward velocities far in excess of very light aircraft, like your Kolb. In short, each
airframe/propeller/engine combination needs to be optimized as a unit, but the Corvair can certainly turn propellers direct
drive as large as most homebuilt airframes can physically accommodate.
Above is a photograph taken during a thrust test of the 72" Warp Drive propeller.
The top gauge shows a very accurate 2708rpm static. It has a pitch setting of 9 degrees. This would
be appropriate for a Pietenpol, J-3 or Stork. The RPM is measured with a digital, optical
prop tach. The bottom gauge, $20, is reading in PSI. This is reading the hydraulic pressure in a
hydraulic cylinder in tension, restraining the test stand from rolling forward. It is in direct
line with the crankshaft. The area of the hydraulic cylinder is 1.52 square inches. Thus, the
actual thrust is 380 pounds. Keep in mind that we are running stock, cast iron exhaust manifolds,
and a full exhaust system with an automotive muffler for sound suppression (my hangar is in a
residential airpark). Additionally, the engine has no cowl, but is using a 7"x24" air scoop
6" behind the prop. The test stand has a mock firewall, which is a blunt 30"x24" rectangle 14"
behind the engine. From testing of cowled airplanes with flight exhaust systems, I can assure
you that they thrust test much higher. Nonetheless, 380 pounds is a very respectable number, and would do a
great job flying a J-3 sized airplane. Compare this with a C-85 powered fully cowled Cessna 140
with a 72" metal propeller pulling 385 pounds measured by myself with the exact same equipment.
I've frequently heard numbers thrown about in the 500-600 pound range claimed on behalf of engines
ranging from 65 to 125hp. When investigated, most of these claims don't stand up, so I would
caution people not to draw conclusions when comparing numbers. Many people who have attended
Corvair College have seen my test equipment and verified its accuracy.
| | Subj: Maximum propeller diameter
| | Date: 6/16/03
Thanks for your reply, William.
I appreciate your thoughts on this project (Piet for Big Boys) and I do give more credence to you guys who have actually built and
flown a Piet. I'm not planning to stray too far from the general proportions of the original Aircamper but I did stretch the aft fuselage
for greater leverage for the increased pitching moment of the 4412 airfoil as well as increasing the vertical and horizontal tail surface
areas (using a scaled up Sky Scout tail feathers profile). Of the few Piets I've flown in, I've always thought an increase in tail volume would improve directional and pitch stability even on the stock Piet.
Just to clarify.... With one of your 'stock' Corvair conversions on a Big Piet your suggestion for a wooden propeller diameter is 68 inches? Any hint as to pitch recommendation? I plan on making the prop myself (education, $ savings, aesthetics, fun and satisfaction) but I always listen carefully to someone with your firsthand experience.
Thanks again for your input.
| | Arlen Anderson, Pietenpol, Papabear108@aol.com
| | Reply from WW:
| | Prop pitch measurement varies from manufacturer to manufacturer. One man's 32" prop is not the same as another's. If you wish a high cruise of 80mph, at 2,800rpm, the following math would suggest
80mph = 7040 feet per minute
7040 x 12 = 84480 inches the plane will travel forward in one minute
If you divide this amount of inches by 2,800 revolutions in the same minute, it will give
you the number of inches forward motion per revolution, in this case, 30.17. This is your
inches in pitch.
You can work these formulas many different ways, but to absorb a certain amount of hp at a
certain rpm, you need a very specific amount of blade area. An engine that's operating at 25"
MAP and 2,800rpm and producing 75hp, like a Corvair, could be called Case A. Conversely, a Continental
A-75 would require about 2,500rpm and 25" MAP to produce the same horsepower - Case B. But,
the difference between the amount of blade area required on Case A and Case B is quite substantial. The Corvair
motor would require approximately 25% less blade area to effectively transmit the same hp into
thrust. This is why big, geared, slow turning props have to be much larger. If you turn props
very slowly, they have to have a lot of blade area to produce thrust, the same way that if
you're going to fly an airplane very slowly, it has to have a lot of wing area to produce
lift.
The greatest old wives' tales told in aviation by people who have never directly
experimented with the engines they're willing to talk about is that the larger, slower turning
prop would somehow be magically more efficient. Having owned, tested and flown all types of
props, thrust tested them scientifically, and worked for or been a dealer for a number of
major prop manufacturers, I can assure you this is an old wives' tale that isn't true.
The 68" propeller I was referring to was a Warp Drive two blade with squared tips. A wood
prop should be slightly smaller, perhaps in the range of 66". There is a lot to the art and
science of wooden propeller making. I've never seen anybody on their first shot produce a
wooden prop that would work anywhere near as well as a Warp Drive. Very experienced wood prop
makers can slightly exceed the performance of Warp Drive with a custom made wood prop. I'm not
discouraging you from manufacturing your own prop, I'm just telling you that you need to be
armed with a lot of good information. Most of the stuff people publish on props is trash. If
you want a good starting point, the 1930 edition of Fred Wick's book on props is the bible.
And I would not attempt to build one without Hovey's book on practical prop making circa 1985.
| | Subj: forged piston source?
| | Date: 6/15/03
Are forged pistons available currently, and if so, what is the source? Also, Corvair Underground is really pushing the Ken Black hypereutectic pistons as being as detonation-resistant as forged. Are these the same hypereutectic pistons that you've already written about in the manual?
Thanks much,
| Jeff Boatright, Manual #5245, jboatri@emory.edu
| Reply from WW:
| | Under no circumstances are hypereutectic pistons as detonation resistant as forged are. It is irresponsible for people to suggest that they are. The Blacks are made by United Machine and Technology, and the manufacturers do not claim them to be anywhere near as detonation resistant. The whole story on pistons was in the last issue of The Corvair Flyer. The engines I'm currently building are using the 88mm VW forged pistons from SC Performance.
| | Subj: Corvair in a Zodiac CH 601HDS?
| | Date: 6/14/03
Any thoughts or info about a Corvair in a Zodiac CH 601HDS. I'm interested in building something with a Corvair and have never built before.
| | Mark King, kinglabwest@earthlink.net
| | Reply from WW:
| | The Corvair/601 is a very popular combination. I'm currently working on motor mounts and other installation
pieces for this combination. Keep an eye on www.FlyCorvair.com for details. Please note that most guys building today are building the XL model, a serious improvement over the earlier models. You may wish to consider this.
| | Subj: Wittman Tailwind
| | Date: 6/13/03
I have a carb from an old C-75 Continental, will it work on the Corvair? Also are there any Tailwinds you know of
currently flying a Corvair engine?
| Stan, Tailwind9@msn.com
| Reply from WW:
| | There's nobody I know currently flying the Corvair/Tailwind combination, although it has flown in the past.
We have several experienced builders working on the combination right now, so before long, we'll have several fresh flyers on this front.
A lot of my flying time was done on an NAS carburetor, which I believe was the same carb used on the C-75. They have different venturis, but the 1 3/8" venturi has supported well over 100hp when installed on a Corvair motor.
| | Subj: Exhaust Stacks
| | Date: 6/12/03
I am interested in a set of your exhaust stacks for a 95hp engine (head numbers 3878569). Do you have any pictures of them?
I have to heat the heads to remove the old stubs, how do the new ones fit? Can they be fitted with the valve etc. already in the
head?
Thanks.
| Peter, vk3eka@yahoo.com
| Reply from WW:
| |
My exhaust stubs bolt directly onto the stock heads with their steel stacks in place. They are not a replacement for the stock
piece, they are the beginning of your exhaust system. We will have more pictures next week on the
Online Catalog at www.flycorvair.com. We're revamping this right now. It will have much better explanations,
and they'll be much easier to see.
The stock exhaust stacks can generally be removed from the head without heating the the head. I'll post a picture of the lever
mechanism I've used to pull hundreds of stacks from heads. You only need to do this if you have bad stacks. My exhaust
stubs will bolt right onto original exhaust stacks.
| | Subj: CORVAIR FLYERS
| | Date: 6/11/03
IS THERE A WEB SITE FOR CORVAIR FLYERS?? THANK YOU FOR MESSAGE ABOUT
ZENITHAIR 701 & CORVAIR. HAVE MY WINGS & RUDDER DONE.THANKS.
| | MAX BUTLER, ZENITHAIR 701, CHEYENNE,WY, MB160016@exchange.DAYTONOH.NCR.com
| | Reply from WW:
| | If you would like to see a partial collection and information about flying Corvair planes,
just check out this new part of our web site: Flying Corvair Planes!.
It's a work in progress, and we're trying to add to it all the time. Check it frequently for
updates, as the results of our Corvair Questionnaire continue
to return from all parts of the country. This is my favorite part of the Web site because it's a
pleasure to admire the craftsmanship of these builders and aviators. It should fill the rest of
us with motivation to go out and complete our Corvair powered birds, taking our rightful
place amongst the group of builders now enjoying the fruits of their labor and the freedom
it gives them.
| | Subj: Engine to prop
| | Date: 6/10/03
Can the engine main withstand the prop torque? Any possibility of a super charger for added power?
| | jchelmecki@aero.net
| | Reply from WW:
| | I assume you're speaking of the main bearings of the motor, specifically the thrust
bearing in the engine. The Corvair motor has a double sided main thrust bearing, which has a
perfect track record during the past four decades of powering the aircraft. You can find the complete
story further down this page by hitting Ctrl+F and typing in "bearing." In short, the motor needs no external thrust
bearing in a direct drive application. I'm currently working on a turbo charger to boost the power
of the application. More details as they develop.
| | Subj: Metal plane to match Corvair, of course
| | Date: 6/9/03
I have been surfing your site for an hour and am excited to think that the
Corvair engine is what I am looking for, inexpensive and reliable.
I have not settled on a plane, other than I want to make it out of aluminum,
as I am a machinist with a shop and am comfortable with metal.
I will beg your indulgence and ask for your opinion about just what kit
plane to make. Fast would be nice, but I am realistic about that. Something
matched to the motor makes sense to me.
I am located just NE of Orlando, and would like to come over for a class
about working with the Corvair engine.
Thanks in advance,
| | Terry Warburton, Geneva, Fla.
| | Reply from WW:
| | Welcome to the club. There are a number of metal aircraft designs that match the Corvair
very well. If you're interested in a single seat design, Kevin Bishop's Ellesay is currently
heavily into the prototype stage, and it was specifically designed for Corvair power. Amongst
two-seaters, the Zenair 601 is very popular with Corvair builders. Neil Hulin is our point man
on the Corvair-601 project. I am developing the installation for his 601XL project, but there
are many, many other guys in the field working from my Conversion Manual on the exact same match.
Feel free to stop by at any time, just call first to make sure we're here. We travel to
airshows, fly-ins and EAA Chapter meetings quite a bit, but are always ready to play host to
anyone here to learn.
| | Subj: Replacing crankcase studs
| | Date: 6/8/03
I have a question regarding the replacement of crankcase studs. I
purchased a motor from an individual who pulled it from his car and stated
it had a blown head gasket. After teardown I could not find any evidence,
although I am not sure what a blown gasket would look like, they look fine
to me. However, when I was removing the heads I did notice three of the
stud nuts in the area of one of the center cylinders did not seem to have
as much torque. About half a turn and they were free. The area around the
base of this cylinder was also very dirty/oily as compared to rest of
engine. To be on the safe side I thought I would go ahead and helicoil all
the studs. My question is, after helicoiling can I reuse my studs? The
green shop manual mentions studs are available in .003 and .006 oversize.
Clark's catalog says to use .006 if you helicoil. Also, do you torque the
studs the same when using helicoils?
Thanks.
| | Mark Sandidge, Madisonville, Ky.
| | Reply from WW:
| | Yours is an excellent technical question. The sign of a blown head gasket is some of what
you described, plus obvious blow by at the top of the cylinder. I would not assume just because
it had a blown head gasket that it was pulling the studs out of the case. Careful inspection is in
order. Take a straight edge and compare the height of all the studs. They should be within 1/16"
of each other. If none of them unscrewed on disassembly and they're all about the same height,
and there's no obvious defects, your blown head gasket may not have damaged the studs.
Clark's is a good outfit, but they are mistaken on this one issue of studs. As stated in the
Conversion Manual, the thread on the stud is NC5-16, not 3/8-16 like a helicoil. Use the split
die method outlined in the Conversion Manual (available for $59 in the U.S., or $64 including S&H outside the U.S., by check or money order payable to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802, or by credit card via PayPal at the Online
Catalog) if you are helicoiling and use the stock size studs.
A stud that screws into place when using helicoils must be locked down using thread locker.
My preferred LocTite is 620. A stock stud is like a pipe thread in that it bottoms out at some
point. Any helicoiled hole is like a nut and a bolt.
| | Subj: Usable heads?
| | Date: 6/7/03
I have just recieved two engines from the US. They are:
Motor 1 RU with 8049 crank and 3880708 Heads; Motor 2 is an RG with 8049 crank and 3878569 heads.
The RU is in better condition.
Your Manual states that both are unsuitable (page 19), yet page 46/47 says the 3878569 heads are OK. Could I use these heads on
either engine? If so, I presume I would only need another set of suitable heads for the second engine.
By the way, I have now moved from St. Helena back to Australia; much better airplane building environment!
Thanks for your time.
| | Peter, Australia, vk3eka@yahoo.com
| | Reply from WW:
| | Both of your blocks came from the factory with something called AIR installed as a
system on the engine. AIR is not air conditioning, but rather emissions control equipment.
Stripped of their external paraphernalia, the only thing about these engines that would then
be unsuitable for flight would be their no quench area combustion chambers. You are correct that
acceptable heads could simply be swapped onto these motors. As evidence, this already has been
done on the engine you referred to as Motor 1. The 0708 heads did not come on the RU motor from
the factory. But, they are excellent heads for a flight conversion. In short, Motor 1 is ready
to go. There is some debate about the heads on Motor 2. The 8569 heads are listed as 8.25:1
compression, and I think they probably have a quench area and are suitable for flying. Complete
open chamber heads, such as the turbo heads, are the ones that are not suitable for flying. GM
literature lists these as 8:1 compression heads. A 3883862 is an example of a 95hp open chamber
head. All you have to do to verify that Motor 2 is ready is check for the quench area in the
combustion chambers.
Congratulations on getting two good core engines to the other side of the earth. This goes
a long way to prove that anybody who wants Corvair power for their experimental aircraft can readily
have it. Certainly everyone in North America can readily find a motor if they want to.
| | Subj: Pietenpol Power Curve, Props
| | Date: 6/6/03
My nephew & I are researching the possibility of using a Corvair
engine on a Pietenpol.
Do you have available the power curve on the engines??
What prop would you recommend??
Thanks.
| | Harry Myers, harrymyr@vtc.net
| | Reply from WW:
| | As you already know, the Corvair is the ideal engine for the Pietenpol. The updated
long fuselage drawings available from the Pietenpol family are the most ideal ones to build
from for Corvair power. The Corvair engine, built according to my Conversion Manual (available
for $59 in the U.S. (and $64 including S&H outside the U.S.), by check or money order payable to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802, or by credit card via PayPal at the Online
Catalog) produces about 80hp at 2,800rpm, 90hp at 2,950 and 100hp at 3,100rpm. I sell 2-blade Warp Drive
68" ground adjustable propellers for Pietenpols, the same prop I flew for years on my own Pietenpol with great
satisfaction. Most guys flying wood props use 66" diameter with a pitch in the range of 30-34".
Happy building and flying your family project.
| | Subj: How Sweet it is!!!
| | Date: 6/5/03
As you are aware, I am running the 32mm Aerocarb on my engine. The engine, prior to yesterday, had 7 hours running time on it.
One of the things I had been having trouble with was low idle rpm. I simply could not get the engine to stay running below 1000 rpm.
I was beginning to think that the 32mm carb was not right for this engine and I might need a 35mm. So, I decided to study the
manual on the carb again and see if there was anything out of the ordinary I was doing. The manual stated the carb comes with
three needles for proper tuning to the engine. Number one is leanest, number 3 is mid range and number 5 is richest. So I got to
thinking about this, and it seemed to me at low idle I simply could not get enough fuel to the engine to keep it running. I took a look
at the two spare needles I had and they were #1 and #3 so I decided to remove the one in the carb to see what number it was and it
turned out to be a #2. Well what do you know, I installed the #3 and followed the instructions on tuning the carb, hit the starter, and
she fired right up. I allowed her to warm up at 1000rpm then began to slowly lower the rpm and reached 600rpm. I was awestruck.
This engine was purring like a kitten at 600rpm with absolutely no vibration. I simply could not believe the performance I was getting
now that I installed a needle which gave me a richer mixture at idle. Once again I am on top of the world with excitement about the
Corvair engine and I would like to thank both you William and Grace Ellen for all you guys have done to get me to this stage. Also, I
hope a visit to my house is in your plan when you visit Broadhead and Oshkosh this summer. I have bragging rights you know and you must see how I have progressed since you were here last summer. How Sweet It Is !!!
| | Mark Jones, KR2S N886MJ, Wales, Wisc., flykr2s@wi.rr.com; Visit my KR-2S CorvAIRCRAFT web site at
http://mywebpage.netscape.com/n886mj/homepage.html
| | Reply from WW:
| | Great to hear from you. There comes a point in every man's building where he must break
down and suffer the ultimate humiliation of actually reading the directions. I myself am frequently
forced into this position. The photos on your Web site do show the great progress. Glad to hear
the 32mm Aerocarb is working out for you. Certainly is a quality piece. We're planning on
being at both Brodhead and Oshkosh, and we'll certainly stop in on the way, weather permitting.
You're not far off our path. Thank you kindly for the invite and the update.
| | Subj: Wag-a-bond Power
| | Date: 6/4/03
I am building a Wagaero Wag-a-bond from plans. Fuselage welded and tail feathers. Was thinking of powering with a C-85 or
O-200, however looking at the Corvair engine; this might be the way to go.
Is the Corvair College still operating? I spend my winters ( Oct. - April ) in Hudson, Fla., and may attend the
college next fall or winter if it is available.
| | Carl Rivait, Wag-a-bond, Hudson, Fla., rivaitca@earthlink.net
| | Reply from WW:
| | Here's how good a combination I think the Corvair and Wagabond is:
I'm building one myself. I have a completely welded fuselage that has been modified from a damaged
Colt. The Wag-Aero plans set fuselage is more closely related to a Colt than a Vagabond. I work
on it a couple hours every day with the intention of getting it flying by the end of summer. We'll
post pictures of it on FlyCorvair.com shortly.
Corvair College includes many classes throughout the year, but the big one is in the spring
during Sun 'N Fun. You're always welcome to bring your stuff and come by the hangar.
| | Subj: Starter Kit Prices
| | Date: 6/3/03
I noticed a reference in passing in your web Q&A that you now have starter
ring gears and are looking at stocking complete starter kits. Hey, sign me
up. Anything I can get from you I'll buy. The payoff for me is that I don't
need to stop building the aircraft in order to run around town sourcing all
these bits and pieces. Let me know the extra cost and I'll get a cheque in
the mail.
| | Neil Hulin, Zenith 601HD, Cincinatti, Ohio, nhulin@hotmail.com
| | Reply from WW:
| | We have a good supply of the starter kits in stock now because we did all the running
around and lots of it for you, and the rest of the gang. Here's the breakdown on the prices, which include
U.S. shipping:
Bracket set, $79
New lightweight ring gear with all machine work done, $89
Puck, $189
Alternator pulley with all machine work done, $59
Replacement Subaru starter gear, $20
These introductory prices include U.S. shipping until Oshkosh.
| Subj: Is this a good candiate? Short time window - please answer soon
| | Date: 6/2/03
I recently came across this item for sale:
"Corvair 102 H.P. Engine with 94,000 original miles that was removed from my now turbocharged 1962 convertible just 3 months ago. I decided that since I wanted a bit more umph! a turbo would do the trick but had to replace the entire engine. You cannot just turbo charge a standard engine without rebuilding it to turbo specs. The engine is 99+% complete and only missing the mount for the oil filter-readily available. Everything else is there and functions fine. The only glitch is that there is some blowby but no smoke from the tail pipe. The carbs were just recently rebuilt and the engine starts with very little effort. Once started, it has never stalled unless it was my sloppy clutching."
The case is stamped T0615YN, for whatever that's worth.
Is this a good candidate for conversion? It looks like a heckuva deal. The shipping cost from the Gulf coast to Minnesota may be more than the cost of the engine itself. There's a very short window of opportunity, so I'd really appreciate a quick answer.
Regards,
| | Corrie Bergeron, Minnesota, corrie@itasca.net
| | Reply from WW:
| | A 102 is an early model motor, and is only 145cid. It is not a good candidate for a
flight engine. The 1964-69 motors are all 164cid and have a few internal differences that make
them better motors. I would pass up a deal on any early motor. It's not worth your time to
pursue them. There are plenty of 164cid motors to go around. My Corvair Conversion Manual,
available for $59 in the U.S. (and $64 including S&H outside the U.S.) by check or money order payable to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802, or by credit card via PayPal at the Online
Catalog, contains all the numbers, codes, etc. so you can get the right engine for your
project.
| | Subj: Heads
| | Date: 6/1/03
Can I use a 3813513 head on one side and a 3856759 head on the other side? Thanks.
| | Jim Daron, Pietenpol, Manual # 5498, Malabar, Fla., cjdaron@cfl.rr.com
| | Reply from WW:
| | The 513 head is from an early model 80hp and cannot be used with the other head, which
is a good one for your conversion. The 759 uses the 1965-69 cylinder, so make sure you find
another '65-69 head to match it.
| | Subj: Case and Crank
| | Date: 5/31/03
I've torn my engine down to parts, excepting three really ugly case studs
which I hope to get done this weekend at a borrowed drill press.
Unfortunately, my outside studs were bad enough on the tops to forget any
possibility of reusing them, so I decided I'd rather change them all and
know what I have.
| | I'll probably be looking to send my crank your way after verifying some
measurements once I get the service manual. I saw on somebody's Web site
that you have a shipping box designed for the task, so what is the usual
protocol for doing this?
Thanks,
| | Clay "Hoppy" Hopperdietzel, Zenith 601HDS, Tomball, Texas, hoppy@houston.rr.com
| | Reply from WW:
| | Got your phone message. Almost all cranks will clean up with a 10-10 regrind. In land based applications, cranks are commonly reground much more than this in high performance apps. But I only recommend things I've personally flown, and therefore, 10-10.
I used to ship the cranks in specially made wooden cases. But UPS continuously damaged the
cases in a way that they appeared to have been dropped consistently from 3 or 4 feet. Today we
ship cranks wrapped in plastic, rolled in a large beach towel, wrapped in bubble wrap, in a
cardboard box, by USPS. Seems to work better.
If you're building a 3100cc motor, keep in mind that you cannot helicoil any of the stud holes in the case. Be cautious when removing and replacing studs in a potential 3100cc engine for this reason.
| | Subj: Bushmaster
| | Date: 5/30/03
I am writing you to settle my dispute with myself over the
Corvair. I fly a Bushmaster and really want to do the 4-stroke conversion.
Lots of people that I know have installed the Subaru in them and they work
great. The Subaru weighs about the same installed wet, but is very expensive
to build with a reduction. My question is: If I install the Corvair with
direct drive, what can I expect for performance? Will this plane be good on
floats? I have been following your stuff for a while, but have not seen a
plane similiar to mine yet that has this conversion. My dad is Murray Green.
He is very close to having his Stork completed with the Corvair, but I can't
wait that long to see how his reacts. Plus his is very high lift.
I thank you for any information you can give me to get me on my way.
| Mike, shannon.l@vcm.ca
| Reply from WW:
| | We've recently done a lot of very accurate thrust testing on the Corvair, turning a 72" Warp
Drive prop. This was done to satisfy the curiosity many people have about the direct drive
turning a much larger prop. The engine produced nearly 400lbs. of static thrust for a pitch
setting that would be appropriate for an 85mph cruise. This was running the engine with no
cowling, a blunt air scoop, and a flat 30x24" firewall behind the motor. The engine also was
run with complete cast iron exhaust system and a large muffler for noise abatement reasons. It
static'd the Warp Drive prop at 2700. Even at this rpm, the thin Warp Drive blade sections
were not excessively noisey. In short, I think the engine would be very appropriate for your
aircraft.
| | Subj: Pulley p/n
| | Date: 5/29/03
To those using the front mount starter & alt setup per Mr. Wynne's plans, the p/n for the GM pulley has been changed from
3927116-AV to 14087008. You can find new pulleys on the web for $6 + $7 S&H. I purchased mine for $10 from the local GM
dealer. Just an FYI.
The puck is complete onto the prop adapter.
| | Al Manley, Longmont, Colo., amanley@attglobal.net
| | Reply from WW:
| | Nice piece of homework. Seriously, you win the award for best customer supplied
information this month. And the award is: a free one-year subscription to The Corvair Flyer
newsletter. We're working in the hangar right now, and decided to institute this new award
based on the fact I was having a very difficult time tracking down the new pulley number
myself. This is a very good example of how everyone has something to contribute, and why we
refer to the Corvair as a movement of friends, as opposed to merely our business.
| | Subj: Kit Plane dude
| | Date: 5/28/03
I saw your story in the latest Kit Plane mag.
| | Brent Brown, Autogyro, Fayetteville, N.C., brownb@soc.mil
| | Reply from WW:
| | Thank you.
| | Subj: Oshkosh
| | Date: 5/27/03
Will you be at Oshkosh this year? If you are, and I ordered some stuff from
you, would it be possible to pick it up at Oshkosh?
Items would be Conversion Manual, Aluminum CNC top cover and possibly a
crankshaft. All will be paid for before Oshkosh.
I have just got my engine, a 110hp with all the right numbers. It's going
into a GN1.
Thanks,
| | Ken Rickards, GN1, Markham, Ontario, krickards@CVCI.com
| | Reply from WW:
| | If we were driving to Oshkosh, I would gladly accommodate your request. However, this
year, the plan is to fly by Taylorcraft. It's a 1946 BC12D which has a gross weight of only
1,200lbs. We'll be cutting it close enough with a week's worth of camping gear and the normal
products I bring to sell at airshows (Manuals, Videos, Top Covers, Hybrid Studs, Safety Shafts,
Oil Pans, etc.). If you have a U.S. address you'd like us to ship to in Oshkosh, perhaps we could save you
the across the border fees.
A quick reminder on crankshafts: I do them only on an exchange basis. You get your exact crankshaft
back. I did about 100 cranks last year, and got only about half the cores back. This year, I'm
making a special effort to ensure everyone gets their exact crank back instead of the exchange
and core program I ran last year.
You can check the EAA's Web site, AirVenture
Forums, for the latest schedule. So far, I am scheduled to speak on Converting Corvair Engines 7-8:15p.m. Wednesday,
July 30, in the Aircraft Shopper Online Pavilion 5. Check the AirVenture Forums site later for more dates.
| | Subj: Hybrid torque
| | Date: 5/26/03
How much torque should I use on the studs going into the crankshaft???
| | Larry Baxter, Manual #5124, Adelanto, Calif., ssshvac@msn.com
| | Reply from WW:
| | The studs should be double-nutted and torqued into the crankshaft at 22-24 foot pounds of
torque, lubricated only by LocTite. Remember to clean off all excessive LocTite after they're
torqued in place. The LocTite I recommend is 620. It's expensive, but it's more heat resistant
than the regular red LocTite. Please note that we haven't had any problems with the red LocTite,
but are still switching to 620 now.
| | Subj: Fuel octane
| | Date: 5/25/03
Mark Langford's Web site said he'd burn lower octane fuel in the 3,100cc motor. Is this possible?
| | Gordon Alexander, Shakopee, Minn.
| | Reply from WW:
| | Yes, this is possible. The first person to fly the 3,100cc motor, our friend Steve
Makish in South Florida, tested all types of fuel and his compression ratio lowered in a method similar to Mark's. I'm
pretty sure that when we broke Mark's motor in at Corvair College #3, we used 100 percent av gas. Although
Mark's Web site may not reflect this, I had a phone conversation with him a few months ago
in which he explained that after a long discussion with a fuel expert, he's pretty much sold on
operating his airplane on 100 percent av gas for many operational reasons beyond mechanical
compression ratio. Many people know I'm a fan of 100 low lead, and the technical discussion
surrounding this is in the latest copy of the Conversion Manual, available for $59 in the U.S.
($64 including S&H outside the U.S.), by check or money order payable to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802, or by credit card via PayPal at the Online
Catalog.
| | Subj: Cozy or LongEZ
| | Date: 5/24/03
Would the Corvair be a good choice for the Cozy Classic or the LongEZ.
| | Yosef, y_kristos@yahoo.com
| | Reply from WW:
| | I believe that the Corvair is a poor choice in either of these aircraft. The only combination
I would consider would be a 190cid engine in a LongEZ that was built to Burt Rutan's concept
of a very light day VFR airplane. Although these aircraft are thought of as being efficient,
they almost exclusively use engines far more powerful than the Corvair. Many pusher canard aircraft
have extremely high stall speeds for a single engine plane (they cannot utilize flaps). This
high landing speed, combined with the engine's mass behind the passenger compartment, works
against your safety in an engine out situation. The logical argument here might be for utilizing
only the absolutely most reliable engines operated at their least percent of power output in
these aircraft. To me, that would be a large, brand new Lycoming.
| | Subj: Camshaft bore?
| | Date: 5/23/03
We just finished tearing down and cleaning two 110 engines. These two engines and one other have pitting in the camshaft
bore. How much pitting is allowed if at all? Do you recommend crocus cloth for light pits and buildup and rebore for deeper
pits? I would appreciate your input.
Best regards,
| | Paul Mallard, Miami, Fla., papaquack@aol.com
| | Reply from WW:
| | There are a lot of old wives' tales about Corvairs wearing out the camshaft bores. This
may be an issue for guys building 8,000rpm race engines which will have cam profiles that will
require enormous spring pressure on the valves, but for our application, I have found virtually
all Corvair cam bores I have inspected usable.
Light pitting would not bother me, as the bearing area is very generous. I would be hesitant about any
technique that would lead to material removal, such as any real sanding, etc. If you truly
have the rare case with a damaged bearing bore, I would just find another case. The value of
a case is about $50, and there's no conceivable technique to rework one which would cost less
than buying four or five spares. A good indication that this has not proven to be
a problem in Corvairs is the fact that there really are no methods of reworking this area in
the engine. If Corvairs damaged their cam bearing bores frequently, or if the cases were highly
valuable like aircraft engines, there would be techniques such as line boring or oversize cam
blanks readily available. With the reliability of a Corvair, there's never been a need to develop
these.
We recently had a visitor to the hangar who was nothing short of amazed that there are no
cam bearings in the motor. He expressed some degree of wonder at whether or not this brought into
question using the engine in an aircraft application. He was even more stunned to learn that no
Lycomings or Continentals have cam bearings either, and they have a pretty good record as airplane
engines go.
| | Subj: Corvair in an Osprey?
| | Date: 5/22/03
I attended your seminar at Lakeland and bought a Manual, No. 5545, and a video and would like to build a Corvair engine.
I have bought an Osprey project in Miami and it needs an O-320 to have enough power. I know in your book you mention
that the Corvair is not capable of that much power, only 120hp with the large cylinders. I just wondered if you had any ideas
for a few more hp, i.e. Rinker box or maybe turbo, stroker, maybe even a direct drives oldsS. I have successfully converted a
Mazda which is flying in a Grumman every day, but I don't want to do that again as it was a major pain in the ass and I don't
like that gearbox.
Kindest regards,
| | Bill Fisher, wfisher5@bellsouth.net
| | Reply from WW:
| | I don't believe the Corvair motor in a simple reliable form can be used to power an
Osprey II. An Opsrey is a high performance amphibian with very high wing loading, especially
for an amphibian. Most people conclude that an O-320 is the minimum engine. Corvairs have been
flown in their large displacement form, with gearboxes and turboed. But I feel that if you combine
all of these elements in a single motor, it would start to get as expensive as an O-320, yet
would not posess the simplicity and reliability of a run-of-the-mill O-320. It's very hard to
get a 164cid engine to do the work of a 320cid engine. And it certainly cannot be done inexpensively
and reliably. All of the issues you mentioned with the difficulty converting your previous project,
with liquid cooling, gearboxes, etc., are the reason why I focus all of my work on a simple,
direct drive, air-cooled engine.
| | Subj: Your Corvair engine for sale
| | Date: 5/21/03
I was lucky coming across your adv on Net concerning
your Corvair engine of which I've been searching
for, with the price of $2,700. Could you please send the
pics and tell the condition of the engine so I can
make an arrangement for the payment asap.Thanks.
| | jcbrazaville@yahoo.com
| | Reply from WW:
| | I am not sure what Web site still lists this, but the engine was sold several years
ago to John Martindale in Australia, who is now flying it in a KR2. The good news is that you
can build one yourself for less than $2,700. You start with a Conversion Manual,
which will guide you through finding a core motor (not a difficult task) all the way
through its conversion and installation. I highly recommend against buying engines offered
for sale which are already converted. Very few of these crop up, and in almost all cases,
they are converted by people with very low levels of craftsmanship who would be afraid to fly
it themselves but would unconscionably offer it for sale so someone else could fly it. The best
approach is to build your own motor for yourself. It's what all the succesful builders are
doing. Start with the Conversion Manual, available for $59 in the U.S. ($64 including S&H
outside the U.S.), by check or money order payable to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802, or by credit card via PayPal at the Online
Catalog, which also lists all the products you would need for the conversion.
| | Subj: 95 HP or more?
| | Date: 5/20/03
William, Before I purchase your Conversion Manual I want
to know if I'm going in the correct direction. Just
purchased a $100.00 1968/69 95HP (no smog) engine.
1. Will the HP vs weight be ok for my KR2S?
2. If needed can I increase HP with new jugs and still
use the heads.
I have experience rebuilding several auto engines
including many VW engines.
If the 95 HP will work I will be ordering your Conversion
Manual.
| | Steven Phillabaum, KR2S, Auburn, Alabama, skphil@charter.net
| | Reply from WW:
| | Your late model 95 no-smog engine is the perfect candidate for a KR2/KR2S conversion.
We have four KR2s flying now on Corvair power. I think the 2S will be an even more impressive
aircraft. All the options of different jugs are available with your motor, but even a basic
rebuild and conversion will provide outstanding performance. Additionally, the KR2 is one of the
most popular Corvair conversions. I have sold hundreds of Conversion Manuals to people who are
now working on this. I've developed and have jigs and tooling for motor mounts, etc., and have
spent a significant amount of time to integrate the entire package to make it an easier installation.
I went through all of this effort because it is such a good match, and I expect to see a lot
more of them take wing this year. The Conversion Manual is available for $59 in the U.S., $74 for international builders, including
CANADA, by check or money order in USD payable to William Wynne, P.O. Box 290802, Port Orange,
FL 32129-0802, or by credit card via PayPal at the FlyCorvair.Com Online
Catalog.
| | Subj: Sportsman 2+2
| | Date: 5/19/03
I only have read info on the Sportsman 2+2 in Aerocrafter and it lists an
O-290 with 135 hp. I have not been able to find weights for this engine but
it seems at a glance this could enable a Corvair O-190 fit as there should be
a little weight savings. What do you think?
| | Scott Schermerhorn, Schermerhorn.Scott@delcoremy.com
| | Reply from WW:
| | A Sportsman 2+2 is a homebuilt replica of a Piper PA-14. The replicas tend to be heavier than
the original, and the original was something less than an exciting performer with a medium-size
Lycoming. Today, most Sportsmans are built with 180hp Lycomings.
An O-290 Lycoming is 290cid and it produces its rated power at 2,700rpm. A direct drive
O-190 Corvair could produce the same hp, but it would require much higher rpm, which would
necessitate a far smaller propeller. This small propeller would not be a disadvantage on a sleek,
small airplane like a KR, but it would not as effectively turn hp into thrust at low speed
required for a Sportsman. Thus, the Corvair is not an effective replacement for an O-290, especially
in larger, heavier airplanes.
If you like the Sportsman, you should consider the two-place version: The Wagabond. It is an
excellent match for the Corvair, and we have at least two people currently working on them. The Wagabond's
original intention was for 100-120hp, which makes it right up the Corvair's alley.
| | Subj: Selling the Q-200, 'Vair in a Tailwind?
| | Date: 5/18/03
I have decided to either sell or abandon my Q-200 project for now. I've
opted for a Tailwind instead. What do you think about a Corvair in one of
these? They have flown on a wide variety of motors, so I think it would be
most suitable. I've also been thinking, since they can handle the weight,
of turbo-normalizing or even 3-5 psi above SLP. What would you think of
this? How much power could you guestimate I'd get with this setup?
Finally, which heads should I use? Thank you!!
| | Chris McAtee, subcanis@hotmail.com
| | Reply from WW:
| | The Tailwind is an incredibly good airplane. It is celebrating its 50th anniversary
this year. But it is by no means a stagnant design, as major updates were done on the design
as recently as the 1980s. I was lucky enough to fly with Steve Wittman in his
own personal Tailwind, N37SW. The Tailwind, when built right, is a stunning performer of efficiency.
While a Tailwind might be a few mph slower on the same hp, the Tailwind's advantages of a 20mph
lower landing speed, the ability to fly off grass, and handling qualities that can be matched
by few light planes (which a Q-200 could never hope to match) in my opinion make it a better choice.
All turbo work without constant speed props is boosted, not turbo normalized. I've done some
homework on this, and I feel that the best heads would be the same heads I recommend in the
Conversion Manual (available for $59 in the U.S., $74 for international builders, including
CANADA, by check or money order in USD payable to William Wynne, P.O. Box 290802, Port Orange,
FL 32129-0802, or by credit card via PayPal at the FlyCorvair.Com Online
Catalog). I would not use the factory turbo heads. With the right turbo, and low boost,
you could easily get 120hp. But the real key would be that you could still have 100hp at 10,000 or so.
By the way, Wittman's airplane that I flew in had the direct drive Olds engine in it. It had
a 62" prop that was a cut down prop from an O-200 (this is a bad idea - Don't Even Think About IT).
But importantly, the prop turned 3,500 in cruise and produced a lot of efficient thrust. This
was the handiwork of Steve Wittman, the acknowledged master of light aircraft efficiency, at his
best. When you encounter people who tell you that props should never be spun over 2,500rpm for
efficiency, that's their opinion against the experience of men like Steve Wittman. I know which is
more valuable.
| | Subj: Props
| | Date: 5/17/03
I really hate to ask this question but I know nothing about props.
I have a 68" three-blade Warp Drive prop I purchased through Zenith in a
FWF package for the Subaru. Can I use this prop on the Corvair with
opposite rotation? I e-mailed Warp Drive but did not get a response. I also
asked them if I need another prop could I trade in the one I have as it has
never been run. I know you are a distributor and was wondering if you could
help.
Thanks.
| | Mark Sandidge, MSandidge@PeabodyEnergy.com
| | Reply from WW:
| | I know the guys at Warp Drive very well, and they're usually very good about responding.
You probably caught them at a busy point. As long as the equipment is brand new, they may be
open-minded about a trade in. Doesn't hurt to ask. I was unaware that Zenith had packages for the
Subaru. They do have them for the Jabiru, which is a different engine. In either case, right-
and left-hand rotation motors require different propellers. On a Warp Drive, the blades are interchangable
so you can keep the same hub, and replace only the blades. It's educational to go to the airport, look
at a propeller and picture why it cannot be used on a motor of opposite rotation, even if you
turned it around backwards. In any case, the right prop makes all the difference on any engine
installation, and I'll be glad to work with you to ensure you get it sorted out.
| | Subj: Front Starter
| | Date: 5/16/03
I like the simple, improved front mount starter system from the Spring 2003 Corvair Flyer. I purchased the FRA235
and took it to a machine shop to have the center hole enlarged to 3.000".
In their opinion, there is not enough space left for drilling more holes. I don't have a puck to verify the placement of
the 6 AN3 holes. Could you clarify this for me please?
Also, I have checked all the major auto parts stores here in Wichita and I'm not having any luck locating the
fine tooth gear (Accurate Part No. 4-1001). Could you give me an e-mail address or phone no. on this item please?
I did e-mail you yesterday about ordering a puck [Received the order last Saturday. You should have received
my core distributor by now also. Give me a part number and a
price and I'll order a puck. Thanks in advance.]. I think if I had a puck my questions about the ring gear would be
answered.
Thanks again for all your help,
| | Barrett Knoll, Pietenpol, Wichita, Kansas, dknoll@cox.net
| | Reply from WW:
| | You may have missed the Winter 2003 Corvair Flyer which included a drawing of the puck
that showed the 6 AN3 holes will fit with plenty of room to spare. My puck part number is
FS-1. The price is $189, which includes priority, insured S&H in the U.S. (please add $15 for
international S&H, including CANADA). The puck is the only
expensive part in my front starter system. It's made for us on a CNC lathe to very exact standards by
an aircraft manufacturer.
I have pulled together all the other parts so I can offer the complete front starter kit or
any part of it. The fine-tooth starter gear is in stock, and it costs $22. Its part number is
FS-3. Likewise, I have completely machined ring gears, etc. I'm collecting all the drawings and
some very nice installation photos into an info pack. I'll post this on the Web site next week.
Please check the www.flycorvair.com News from The Corvair Authority page
for details.
| | Subj: Second Corvair Manual (For a friend this time)
| | Date: 5/15/03
Dear Mr. Wynne,
(Sounds so formal.... ahem...)
Anyway, this is Richard Alps, and you very kindly sent me one of your Manuals. Thanks. It is great! I was going to say supurb, but I can't spell
that word.
I am currently reading the Manual, digesting it slowly, along with trips to the internet to peruse various CORSA and TCA and KR sites.
Loads of info! Whew.
I may (or may not) have mentioned that I have a friend who is equally interested in aviation, and I have shared the Corvair thing with him. By
the way, his name is Ray Green. He lives around the block from me, and has proved to be a trusted and invaluable friend. These kind are rare, as
I am sure you know.
Anyway, Ray tells me that he is very interested in the Pietenpol Aircamper and/or Sky Scout. I have pics of your Piet, and the story with it. Nuff
said about that.
Just the same, the Piet is a beautiful little parasol, and you gotta love the design. So, you will find PAY PAL has sent you another $59 to cover
Manual #2. He is sitting here as I type this letter to you right now.
I just want somehow to clarify that each of us has a legal Manual, and are authorized to associate with the TCA company and all the functions
you have put into it.
In closing, allow me to say thanks for all the work you have provided for the rest of us.
Sincerely,
| | Richard G. Alps,
Littleton, Colo., Richardalps@aol.com
| | Reply from WW:
| | Good to hear from you. Thank you for the kind words.
People saying nice things about us when we're not there is our primary form of advertisement.
Thank you very much for your efforts. Please tell your friend that we recently got a lot of
new photos of Pietenpol projects that have been flying for years on Corvair power, including a
Sky Scout. We'll post these on flycorvair.com shortly.
| | Subj: Simplicity
| | Date: 5/14/03
Just this very morning I read your piece in The Experimenter magazine [published by the EAA] and I thought
you'd appreciate a piece of wisdom a friend of mine preaches and practices.
He's made a living for years installing and servicing marine electronics and
electrical systems and says: "If you don't install it it can't break."
His own boat is simple and rugged as a rock and so he gets to spend a lot
more time on the water than most of the people he works for.
I'm a real fan of your philosophy and writing. Please keep up the good work.
| | Oscar Lind, Seattle, Wash.
| | Reply from WW:
| | Thank you for the kind words. The ethic of worshiping simplicity is really the
key not only to building airplanes quickly, but also operating them safely. Although I didn't
say it in the article, most builders are capable of producing an airplane complicated enough
that they could not stay ahead of it in the cockpit. Conversely, I'm much more happy to be a
real good stick and rudder pilot who's the master of my simple ship under all circumstances.
| | Subj: 140 HP Corsa engine
| | Date: 5/13/03
I have a 140HP Corvair Corsa engine, would this engine work for conversion?
| | Stan, lguco063@msn.com
| | Reply from WW:
| | Although this issue is covered in detail in the Conversion Manual, available for
$59 in the U.S. (add $15 for international S&H, including CANADA please) by check or money order
payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or by credit card
via PayPal at the FlyCorvair.Com Online Catalog,
I'll give you the quick overview here. The 140hp Corvair motor, distinguished by having
two carburetors bolted to each cylinder head, is a high rpm motor which makes its power at
an rpm not usable in a direct drive application. Additionally, it is the only Corvair motor
with a reputation for poor valve seat reliability. Approximately 5 percent of the Corvairs made
from 1965 to 1969 came equipped with this engine.
| | Though the 140 is frequently referred to as the Corsa engine, many of these motors
went into cars which were equipped with automatic transmissions (all Corsas had manual transmissions).
When the 140 is installed with an automatic, it is given a special 4 degree retarded crank gear that
needs to be replaced if this crank is to be used for flight applications.
| | Everything on a 140 motor, with the exception of the heads, can be used to make a good
flight motor. The heads and carburetors are worth several hundred dollars to Corvair car
collectors. They would gladly provide you with an excellent set of 95 or 110 heads, which
will bolt right on to the rest of the 140 motor. Again, the Conversion Manual has the story in
greater detail. This is just an overview.
| | Subj: Smog Head?
| | Date: 5/12/03
William, your Manual list heads with the number 3878569 as acceptable to use for conversion.
However, Clark's manual
lists
this head number as a smog head. Please clear up the confusion.
| | I was able to find two complete engines with all of the correct designations according
to your Manual. The seller included the following
engines:
1) a turbo case number T0708, head 3856638, and crank 8409; 2) an engine case number
T1004 ZF, head with number 3813516, crank
number not 8409. My question, are any parts useable from these engines?
| | Paul Mallard, Miami, Fla., papaquack@aol.com
| | Reply from WW:
| | I do not believe that the 3878569 cylinder head is an open chambered design. The open
chambered heads, which have no quench area, are the unacceptable heads. While the particular
engine it came from may have been considered a smog motor, I believe this particular head is
usable. The final decision point is cylinder heads which have a quench area are airworthy, and
open chambered designs are not.
| | The ZF case could be a number of different motors from 1961-1964. If it is a 1964, and
it is relieved for a long stroke crank, it would be usable. It is probably not a relieved case
if it has a non-8409 crank. Your turbo motor is a 1964 150hp. Everything on this motor is
usable, except the cylinder heads (see the e-mail below on 5/4/3).
| | Subj: Help finding engine
| | Date: 5/11/03
I want to thank you as today I have received the Corvair Manual.
Tomorrow I will start the procedure/gathering of information towards importing a Corvair engine into Brazil.
If at the end I find that this import is possible/legal, could you help me find a suitable engine?
FYI, as I work for the Brazilian flag carrier (VARIG AIRLINES), I travel a lot to the Miami area, so it would be relatively easy for me to
forward the engine to Brazil.
When the engine happened to be be ready for shipment, I would show up at your hangar, pick-up the crated engine, take it to
Miami Airport and dispatch it home myself.
At a later date, I would bring you the original crankshaft for the exchange for your modified one, and other necessary parts.
Thanx in advance. Best Regards,
| | Oswaldo, Rio de Janeiro, Brazil, oswaldo10@globo.com
| | Reply from WW:
| | Corvair motors seem to be getting popular in Brazil (Please see 5/8/03 e-mail below).
If it is not possible to find a motor, given a little bit of time, I can find you an excellent
core to begin with. I have sent them as far as England and Australia. When I export a core, I
like to take the time to find a near perfect one to avoid international builders having
a problem that might be small here, but harder to fix there.
| | Over the years, I've probably sold a dozen Conversion Manuals to homebuilders in Brazil.
The Ximango motor gliders are imported to the U.S. through our airport here, Spruce Creek,
and our friends speak very highly of the time they've spent in your country. We can certainly
handle your needs.
| | Subj: Spacer for Hand Propping
| | Date: 5/10/03
If the electric starter is left off of the engine (Armstrong starter system to save weight), is a spacer needed under the prop hub? If so, who
sells one; you, I hope?
| | Joe Hemmer, Orangevale, Calif., kiote@cwnet.com
| | Reply from WW:
| | The safety shaft and the hybrid studs both have additional threaded length, so
prior to installing the hub, they can be trimmed down. Two
guys I can readily think of, Pat Panzera and Mark Jones, have chosen to put a small spacer in
here, but I would much prefer, and it is much simpler,
if rear start and hand prop motors just
mount my prop hub flush against the crankshaft.
| | Date: 5/9/03
Friends,
We were just about caught up with Sun 'N Fun when we had to take several days off due to the
passing of the patriarch of Grace Ellen's family on her mother's side. Charles Hayek was 93 when
he died. Grace Ellen was his only grandchild. We will be back answering questions Tuesday.
We appreciate your patience and understanding.
Thank you.
| | Subj: Greetings from Brazil
| | Date: 5/8/03
Greetings from the Brazilian homebuilders! I'm building a kind-of KR, probably
monoplace, and I happened to find a Corvair engine in apparently very good shape,
mid life, good compression, runs smoothly, etc. Not a rare finding considering that in
the sixties, the majority of cars here were USA-made. Two questions, if you please:
1) Sell me, please, your Conversion Manual. The best way for me to pay you is via
credit card, will you take that? And the price for sending abroad.
2) As this engine looks so well preserved, I'm thinking of, in first instance,
installing and flying it temporarily with a minimal conversion, i.e., changing oil
radiator, carb, top and front plates, manifold, exhaust, etc. (what else?) and installing
your prop hub. Then I'd test and fly it until I think it's safe. Is it possible, or should I
open the engine in the first place? I know this question will be answered as I read
your Manual, but your opinion will enlighten me anyway. Thank you so much.
Congratulations for the beautiful service pro-builders!
| Tadeu Passarelli, KR, Brazil, tpassarelli@uol.com.br
| | Reply from WW:
| | Thank you for the kind words. Yes, I take credit cards. You can order almost all my
products via PayPal at the FlyCorvair.Com Online Catalog. Please
also click on the $15 button for International S&H.
| | I would not recommend flying a motor straight out of the car. The Manual will explain
all the reasons why, but the overhaul cost is small compared to the risk of damaging your
aircraft and yourself. The motor is very reliable when converted. Much better than when first
removed from the car. By the way, one of the most popular songs in America this month is
Beautiful, a tribute to the women of Brazil. There's a music video that goes with it,
shot on the beaches of Rio. I do not understand where the men in your country have time for
airplane building.
| | Subj: 701 - RV3 and the Corvair ENGINE
| | Date: 5/7/03
I attended the Corvair Jr. College at San Antonio and am glad to learn that Zenair is going to do the engineering on getting a little more
engine weight into the 701 (saves me from getting it done). Gus and I told each other Seabee stories at the Mini College.
Tell him I said hi.
| | I have seen you mention a couple of times that the RV3 is not a good candidate for the Corvair. I built one of the
first RV3s to fly, and while I powered mine with a 160 Lyc., I have 2 friends that chose 0-200s and they both flew VERY nice.
Vans early literature states "it would fly fine on even a 65 hp but I don't think that will be a popular choice." Not many new
RV3s being built, but the Corvair would make an excellent engine for it.
| | Gotta stop buying Corvair stuff. Made a bunch of
inquiries when I started looking, and engines, heads, cases and cranks keep turning up. Got enough for half dozen engines I
guess.
| | The Corvair Club is the way to get an engine. Nearly every chapter has members that have more engines than they
need .
| | John Bolding, Texas, JNBOLDING1@mail.ev1.net
| | Reply from WW:
| | Good to hear from you. I told Gus you said hello. We both had a good time on that trip.
A lot of serious builders in Texas.
| | You have discovered what I tell people all the time is the truth: The engines are truly
cheap and plentiful.
| | Your experience on RV3s is very close to what other guys have shared with me, that the
RV3 can be built as a light, efficient airframe. Three or four guys are working on
them along with Corvair conversions, with the understanding that the plane would have to be built light and it will be smooth
and efficient, but not in the same league as a 150hp RV3 (it won't be in the same price league
either).
| | I've noticed over the years that the average empty weights of most examples of the same
design appear to be creeping up. If the weight penalty is not bad enough, it's usually a large
increase in complexity that goes with it when people turn good sport planes into mediocre IFR
platforms. Let's hope the pendulum swings back the other way soon.
| | Subj: Exhaust stubs and clamps
| | Date: 5/6/03
I noticed on your Online Catolog you have listed exhaust stubs. Just so I'm clear, they are the stubs that attach to the cylinder heads??
I had a few that were bent and a couple others that I could not remove the gasket material for anything. If they are what I think they
are I would like to order a set.
| | David Vegh, Chandler, Ariz.
| | Reply from WW:
| | Good to hear from you. The parts we offer bolt on to the stock steel stack. If you
need some stock stacks, I have some good ones I removed from other heads. Let me know how many
you need. The cost is $10 each. With a good set of stock steel stubs in place, the pieces we
sell give you the beginning of the exhaust system after this.
| | Subj: Early Heads
| | Date: 5/5/03
Can early heads be modified to work with a later crank? According to my book, they are 8.3:1 CR. Can they be
flycut?
| | Mark, matee@trib.com
| | Reply from WW:
| | It's best not to modify the early heads. When you
increase the displacement, given the same chamber volume, the compression ratio will increase
and your 8.3 will look a lot more like 10:1.
| | Subj: Head question
| | Date: 5/4/03
Here is my "Is my engine ruined" question:
I certainly don't know much about the engines, and suspect the guy I
snagged it from knew litte more than I, so rather than explain what I
thought I bought (other than it was a turbo), these are the numbers:
| | It does have the 8409 Crank, but the case and head numbers don't seem to
match anything in your book. The heads are 3819904. The case is
TII05YR (with the caveat that the 'T's and 'I's may be flakey because
it's hard to tell the difference).
| | Hoppy, hoppy@houston.rr.com
| | Reply from WW:
| | The motor you've run across is a 1964 150hp turbo engine. This would have been installed
in the high performance Spyder. Everything you've got is usable, with the exception of the
cylinder heads. You need to find a set of 1964 heads. The acceptable numbers would be
3856626, 3839887, 3839886, 3819876, 3856632 or 3856631. 1964 was a big production year -
more than 250,000 engines were made that year. You should have no trouble finding a pair of
the above heads. A car collector will certainly trade you, as the 150 heads are worth at
least three times what a set of 110s are worth.
| | Subj: New Case Assembly Video
| | Date: 5/3/03
I received the parts last night, and viewed the video today. It was wonderful. When are you coming out with the next one?????????
| | I do have one question? In the video, when you mounted the two case halves, you didn't use any form-a-gasket
or anything. Is that correct, you don't put anything on either side of the case when mating the case halves?
Thanks.
| | Fish Fischer, Dragonfly, Warrenton, Ore., fishhole@pacifier.com
| | Reply from WW:
| | Thank you for the compliment on the video. All of our videos are directed, produced and
edited by good friend Merrill Isaacson, aka Sky Manta. In addition to being a video wiz, his
Corvair motor was on display and run at Sun 'N Fun this year. Making good videos is a snap
when you have pros like Merrill doing the hard work. Merrill is currently editing Engine Assembly
Video Part II, and we're shooting Part III next Saturday. This trio will cover the whole
engine assembly process. Part I is available for $29 in the U.S. (add $15 for international
S&H, including Canada) by check or money order payable to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802, or by credit card via PayPal at the FlyCorvair.com
Online Catalog.
| | Nothing goes between the two case halves. Between the oil pan, the end covers and the
top cover there's only 1/4" of potential leak area. Experience has shown that oil will not come
out of this area. Every time someone tries to put something between the two case halves, it
effects the clearance on the bearings and allows the case to move. Assemble it bare, just
as I did in the video.
| | Subj: Rans S6S Coyote II
| | Date: 5/2/03
We're building a Rans S6S Coyote II kitplane. We come to the point of
selecting a suitable engine, and the Corvair looks like a great option. We
are good at following step-by-step instructions, but not good at welding and
building parts for an engine. So we're looking for a complete firewall
forward package, ready to bolt on.
Can you supply a Corvair engine and the mount materials to fit it onto our
S6S? As weight is important, we'd probably need some (or all) of the
light-weight options. Electric starter is the only option we'd like to add
weight from, and probably the dual ignition too. Can you quote us a price
for that?
We already own a 3-blade Warp drive ground adjustable prop, beyond that
we're open to all suggestions.
Best regards,
| | Rob, r.turk@chello.nl
| | Reply from WW:
| |
| | Subj: Questions, Questions, Questions!!
| | Date: 5/1/03
Bob Tolliver here from Butler, Tenn., Manual number 5203.
First let me get you up to date.
Yesterday, for the first time since I got my Corvair engine, I had some time to start a tear down. I just got my shop manual and
finally had a break from college during Easter so I could do something fun. It was nice to be able to get my hands dirty again!
My engine looks fair so far. The car had been in a flood, but the water never got over the top of the engine, no water got
inside, just moisture. I pulled the top plate off and the cast iron crank looked fuzzy! It had so much light powdery surface rust
on it. It seems to be light with no pitting. I have yet to get the heads off or the crank out. The case had enough oil in it to
register on the dipstick. At first glance the oil pump even looks good. I will know more after I clean it all up.
| | I am having trouble getting the distributor housing out. I have it loose and it will turn, very stiffly, but won't come out.
Is there a trick or something to this?
| | I have overhauled many engines and have had a lot of luck by just using a cylinder hone and re-ringing the pistons as
long as the cylinder is good and round. I have read that this won't work on a Corvair engine. Why not? I understand if the jug
needs bored out to make it round again, but if it just needs slight honing why do you need new pistons? I understand there is a
problem with possible detonation blowing a hole in a stock piston, but beyond that, why?
| | The Roger Mann, RagWing Stork, RW20 is a side-by-side STOL aircraft about the size of a Super Cub and calls
for a rather huge 72" diameter prop. I want the plane to have maximum STOL abilities, top speed is not really that important
(the Vne for the airframe is 120mph), so what type of propeller do you suggest? Pitch and Dia and where should I get it from?
| | On the same note, I have heard mention of building a left hand rotation Corvair engine. Since I need such a weird
prop size, would this be the way to go for me?
| | In your book you make mention of using new rod nuts. Taking into consideration the low rpm that this engine will be
seeing, and the fact that you say a Corvair engine has never thrown a rod, and as long as the nuts are in good condition, why
not reuse them?
| | I will probably use an aftermarket oil cooler from Summit because mine does not have enough plates. Any advice on
this?
| | I may have missed it in your book, but why not use the stock carbs that came with the engine? They could be easily
relocated underneath the engine on some sort of plenum box and both could be incorporated like a six pack on the old
Dodges. Or for that sake even be moved to behind the motor, if the cowl was big enough.
| | I have been trying to find a flex plate from a Nissan Sentra, but my auto dealer needs a year. What years do I need
to look at? Will the flex plate off of a Chevy Metro work? (I have one I am parting out.)
| | Could you E-mail me an updated parts list? If too much trouble, I can probably find it on your Web site.
| | Will you have a new Manual coming out any time soon? If so, it would be helpful if you included an index in the back. Also,
since you have such experience rebuilding Corvair engines, why not make a manual complete with all the rebuild information in
one so there would be no need to obtain an overhaul manual. I tried to get one from every library I could think of and called all
the auto parts houses, even went to the Chevy dealer. I had to break down and buy one form Clark's. $20 some dollars to get
30 some pages of information. You could put together a more informative rebuild manual and increase the price of your
conversion Manual. It would be much more convenient for us builders. My bedroom has one and a half bookshelves filled with
aircraft books already! Now I have about six on the Corvair including catalogs. Just a thought for you to ponder.
| | I know I have a lot of questions here, but I would be ever so grateful for your time and answers
| | Bob Tolliver, RW20, Butler, Tennessee, Wolfdragon62@wmconnect.com
| | Reply from WW:
| | Nice to hear you're getting your hands dirty. Some very nice aircraft conversions have
been built from motors that at first glance appear to be horrendously filthy and dirty. Careful
inspection and measurement should reveal that most of the parts in your engine will be useful in the
rebuild.
| | A quick correction: all Corvair cranks are forged steel. They are not cast iron. I have
seen many cranks that have an external surface coating of rust clean up very nicely. This is from
having a tremendous amount of moisture in the crank case over a long period of time. Don't be too concerned
about the appearance. Let the clean up and inspection make the decision.
| | Soak the distributor in penetrating oil. You can get better access by taking the oil pump
out and spraying it up the drive shaft hole.
| | My Conversion Manual covers pistons in detail, but I do not like using stock, cast pistons
in a flight motor, especially 35-year-old ones. A number of Corvair engines which have had cheap
rebuilds for cars fail the top ring groove of the piston because honing does not adequately
remove the wear ridge in the cylinder.
| | The only prop you should consider for this airframe is a two-blade, ground adjustable
Warp Drive. Contrary to popular old wives' tales, a 72" diameter Warp Drive can be used at
rpm up to 3,000. This is a perfect match for the direct drive Corvair. I've tested this personally
at my own shop, and we had one of these props on display and running during Corvair College
#4 at Sun 'N Fun 2003 this year. I sell these props for $580 plus S&H. They have an excellent
track record. All Corvair motors are left hand rotation. The option is to build a right-hand
rotation Corvair motor, but I don't recommend it. Virtually all the Corvairs flying have been
standard Corvair rotation (left-hand rotation).
| | The Manual
covers this also, but always use new rod bolts. They're cheap insurance. You never know who
overtorqued them before you. Although broken rod bolts are unknown in Corvairs, why try and
find out what you can get away with, as opposed to doing what we know is better.
| | The easiest thing to do on the cooler is spend $25 with Clark's Corvairs and buy a
12-plate cooler. Most aftermarket coolers are designed to fit in front of car radiators and
are the wrong shape for aircraft cowlings.
| | Yes, I mentioned in the Manual that Corvair carbs have been flown, but I also specify a
number of reasons I recommend updraft aircraft carburetors.
| | The ring gear from the 1987 Nissan Sentra 120cid motor is the one I've previously used. I've
recently shifted to the Ford Taurus ring gear, and the complete update is covered in my newsletter,
The Corvair Flyer. This is available, as well as your requested list of all parts and now videos, at the
flycorvair.com Online Catalog.
| | As for your comments on manuals, let me say this. The GM overhaul manual is an incredibly
good book for $20. It is copyrighted information, and is not available for inclusion in my
Conversion Manual. The amount of time you spent searching libraries was worth far more than
the $20 something you spent. I have worked very hard to hold the cost of my Manual down, and
people respect this. It takes an efficient operation like the one that I run to sell hundreds
of Manuals a year for the modest price I ask and still maintain the customer service standards
which allow me to personally answer letters, no matter how long they are, from individual
Manual owners. Do not fret over having more books on your shelves. I own a houseful of technical
manuals, and I have come to notice that the people who build the most airworthy airplanes tend
to have thick bookshelves. People reluctant to gather and use information tend to have dormant
projects with dozens of glaring mistakes that could have been avoided had they indulged themselves
with a few of the commonly available books. Isn't this the philosophy that led you to college
in the first place?
| | Subj: Eagerly awaiting new Conversion Manual
| | Date: 4/30/03
| | Nice work with spreading your knowledge on the Corvair conversions. I'm pretty handy, but I'm not a motor head by any means.
I'm trying to learn all I can to use the Corvair engine. Thanks for including the copy of the newsletter. If I can learn from it, I'll order it. I really
want to learn about what carb to use, and the differences between them (Corvair carbs, updraft, downdraft, sidedraft, throat sizes,
gas tank location for head pressure....all that stuff). I need to learn when to use a starter and when not to, and what's up with the
blower on top; some people use it, others don't....
| | I hope I can learn these things with the help of people like you and your newsletter. I am also interested in attending your
Corvair College one of these years. I'd like to know if I need to bring all the new parts with me, or can we buy them down there.....
| | p.s. I wonder how long my engine mount should be. Do I need to build and cover the whole plane before I know how long to
make it?
| | Thanks again.
| | John Egan, Litchfield, Ct., jegan@kcc.com
| | Reply from WW:
| | The Manual you ordered will answer all of your questions asked here, but let me take the
opportunity to answer them here quickly so everyone else can learn as well.
| | You mention not being a motorhead. Don't worry about this. The vast majority of Manual
owners have never rebuilt an engine before. This is not a handicap. In fact, it means you're much
more likely to follow the plans and do careful work.
| | The Manual, available in the U.S. for $59USD by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or
by credit card via PayPal at The Online Catalog (please add $15USD
for international S&H, including CANADA), covers all types of carburetors and fuel systems and
the airframes to which they are applicable. In
short, the Corvair will run on a multitude of carburetors. Most of the hours with the engine have
been logged on a Stromberg NAS3 (from the C-85 Continental). Today, the two most popular carb
choices are the MA3SPA (O-200) and the Monnett AeroCarb.
| | As for electric start, I cover all the issues on front and rear starters in the Manual. I
have built and flown both in several versions. I highly recommend electric start.
| | Corvairs are commonly used and were the specified engine for all Pietenpol Air Campers
after 1966. Bernie's conversion was a hand propped engine which retained the stock blower fan.
Many engines were built exactly like this for Pietenpols, and some have logged well over 1,000
hours. The only case where I would use a blower fan/hand prop motor would be in building an exact
replica of one of Bernie's planes. My own Pietenpol had electric start and no blower fan.
| | I offer engine mount kits and complete mounts for a number of different popular airframes.
Some aircraft, like a KR2, do not require you to complete the airframe before building the mount. I have a large database
of completed airframe weight and balance reports which went into the design of my mount. Conversely,
if you were building an original design, you might want to leave the motor mount for last.
| | Subj: Prop L or R
| | Date: 4/29/03
Ordered the new Manual and the engine should be ready this year. My question is, in a
pusher configuration, will I be needing a left or right hand
prop? Plan on getting an in-flight adjustable. Do you think Ivoprop is my best bet?
| | Know you're busy, love the magazine articles.
Thanks for your time.
| | T-lll by the way, wanted beta to back off the beaches down here in S. Louisiana.
| | R. Giroir, T-III, La., fasteel2000@msn.com
| | Reply from WW:
| | Good to hear from you. Yes, if you use the engine as a pusher, you need a specific pusher
prop for it. Under no circumstances should anyone use an Ivoprop on a Corvair motor. I used to
be an Ivo dealer, I know their products well, and there is no Ivoprop that is structurally
sound on a direct drive 4-stroke motor. There may be someone who debates this, but keep in mind,
it's their words and your life. Most people survive their first engine failure in an airplane.
On the other hand, losing a propeller blade in flight has much grimmer survival statistics.
Beyond the fact that these props do not have any type of performance advantage on the Corvair,
no one should accept the unnecessary risk of operating an Ivoprop on a Corvair.
| | I understand the attraction of in-flight adjustable props, and I continuously investigate
new ones coming to the market for their applicability to Corvair engines. The only prop which I
believe is light enough, has an advanced blade design, a simple in-flight mechanism, and comes
from a reliable, stable company, is the Hoffman. Hoffman props are made in Germany, and are
frequently seen on certified motorgliders.
| | Subj: Finding an engine.
| | Date: 4/28/03
Hi William, my name is Keith Smith and I'm looking for an engine to power a KR2S that I hope to start building within the next
2 years. My question is: What types of cars did GM put these Corvair engines into? If I were to look for one in the paper, what
would I need to look for?
| | Keith Smith, Ssmithsk3@aol.com
| | Reply from WW:
| | From your comments, I assume you're a member of Generation X. I myself am one of the last of
the Baby Boomers and I can remember when a lot of people still drove Corvairs as a daily driver.
The economics of the engine make it attractive to a lot of guys getting ready to make their
first mark in aviation. You are in good company.
| | The Corvair was a separate model of cars built by GM that were sold under the Chevy
banner. Inside, they are truly Chevrolets in the sense that they were designed, built and sold
through the Chevrolet division. If you were to run an ad in the paper, you would be looking for
a 1964-69 110 or 95hp Corvair motor. These would have been installed in Corvair vans, pickup trucks,
2-doors, 4-doors and convertibles. This is just the same as the way GM made 2-door, 4-door and
convertible Chevelles.
| | My Conversion Manual details all the information you'll need for an effective engine
search. It is available in the U.S. for $59USD by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or
by credit card via PayPal at The Online Catalog (please add $15USD
for international S&H, including CANADA).
| | A couple of years ago, I drove from Florida to New Jersey and back in a friend's 1963
Corvair Coupe. The car was lowered, had wide tires on it and was painted bright red. It was
different looking, even for a Corvair. I stopped in a Georgia gas station, and an 18-year-old
attendant wearing a Chevrolet hat was a little puzzled as to why I was putting gas in the front
end of the car. He was very curious and I showed him the engine in the back. Although he was
very interested, the car must have seemed like some kind of strange import to him. He asked me,
"Who made this car?" Noticing his hat, I thought he would enjoy hearing that this innovative
product was made by his very own beloved Chevrolet. When I told him this, he gave me a look
like I was the worst, lying, blasphemous, Commie bastard he'd ever met in his entire life.
I showed him the Chevy emblems on everything, but he still wasn't convinced.
| | Subj: Combustion Chambers
| | Date: 4/27/03
The Conversion Manual that I just got states "that the heads from the low
compression smog 110hp and 95hp engines are NOT
RECOMMENDED."
| | I've not listened to Rush in many years, but he used to have a saying, "words
mean things." I believe that you were stating to not use "low compression smog,"
be they 110 or 95, not that all 95s are bad. On Page 18 of the new Manual,
you speak highly of the 95 engine. You go on to say that the 95 SMOG head has
no quench areas, whereas the head in the photo in question clearly has quench.
Please explain. Thank you.
| | Sam Sayer
| | Reply from WW:
| | You read this correctly. What I'm against are heads that do not have a quench area.
By far, the vast majority of 95s do have a quench area. I have built and flown numerous engines
with these heads, and they work very well. Ditto for the 110 heads.
| | The heads I do not like are the open chamber, no quench castings. These include the smog
engines and the 180 turbo heads. These heads are rarer than people think. My guess is that they
were something like 5 percent of the 110/95 production. But, I do want people to be alert for
this. I personally have flown time on the wrong heads, and can assure you that they will fly
and work, but they reduce your resistance to detonation. For the small effort of getting the
correct heads, you can be confident of building a better engine. The photo in the Conversion Manual
illustrates the sort of heads you should be looking for. For all those who do not have the
latest version of the Conversion Manual, it is available for $59USD in the U.S.
by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or
by credit card via PayPal at The Online Catalog (please add $15USD
for international S&H, including CANADA).
| | Subj: Early Motor
| | Date: 4/26/03
My son, Chris McAtee, and I are building a TriQ and plan on powering it with a Corvair. Chris ordered your Manual and then headed
off to college to let me continue working. After letting the project sit for a couple of years and waffling on the engine choice, one of
my flight students, Dave Caylor, purchased a Piet with a Corvair. He showed it to a prof of engineering at our local college who then
wrote you a letter that you posted on your site. Dinking around one day, I looked up your site and saw his letter. Since he
mentioned that he had several running Vairs and being in the same town and having little luck finding an engine core, I e-mailed him.
He promplty responded that he had just junked out a running '64 and had the engine in his way at the moment. To make a long
story short, I headed out with your Manual in hand. After checking the suffix number on the case (engine complete with all fan
shrouds on) and seeing the '64 sitting there (it is a "YN" number), I purchased the engine after being assured that the engine
was probably the original. After teardown, the head numbers (3813516) match those of an early 102 horse and it has the wrong
number on the crank. It is probably a 145 (I'll mic the cylinders on Saturday).
| | Question: Is anything on this engine useable? It is in VERY good condition. Are the cases for the early YN engines the
same as the 64 YN cases? If I get the stronger rods from the newer engines, will the OT-10 cam fit?
Boils down to......did I spend $40.00 badly?
| | Mark McAtee, TriQ, Casper, Wyoming, matee@trib.com
| | Reply from WW:
| | You have the bad luck to have gotten a 1961-63 engine from the 1964 car. The good news is there is certainly $40 worth of parts on the engine. The main difference between your motor and a long stroke case is a slight relieving to allow for a longer stroke crank. An hour's work with a die grinder makes a short stroke case capable of handling an 8409 crank. It is not difficult work to do. The OT-10 cam will fit right in the case. All the other stuff will bolt right to it. Chances are you'll come across a 1964-69 motor for less money than it would take to buy the crank, rods and heads separately. Either way, your $40 was a very inexpensive starting point. I don't believe anyone else in America spent $40 last week and got as many aircraft engine parts as you did.
| | If anyone knows of any engine leads in the Casper, Wyoming, area, please e-mail Mark directly.
| | Subj: Corvair Fold-A-Plane
| | Date: 4/25/03
Friends,
We ran a short story on Steve Rahm's new single place project in the last Corvar Flyer
newsletter, Spring 2003. If you'd like to take a look at a professionally designed
single seat airplane for Corvair power, here's a link to Steve's site:
Corvair Personal Cruiser.
| | William
| | Subj: UAVs
| | Date: 4/24/03
I'm doing a general survey for a large UAV company into
the usability of various engines. Where can I find more technical
information (Lubrication, Ignition, Weight, displacement, BSHP, FF,
BSFC, etc) about Corvair engines? The Web site does not seem to list this
info.
TIA,
Regards,
| | Geraldo van den Heuij, The Netherlands
| | Reply from WW:
| | Although I know all the data you need on the Corvair motor, UAVs (Unmanned Aerial
Vehicles) really only have two applications in practice: government surveillance of civilians and military applications.
I am in no way interested in assisting anybody with the former and would only assist my own countrymen with the latter, but I am quite sure that the U.S. military has much better stuff than could ever be operated by Corvair motors.
Hope you take this the right way. I'm sure somebody in your home country would respond exactly the same way if the roles were reversed.
| |
| | Subj: Thermal Efficiency
| | Date: 4/23/03
G'day. I'm an Australian living in Melbourne who has a great love of aircraft and who regulary
reads the information on your Web site.
| I note that the specs on your Web site show that the Corvair, particularly the O-190, is
an oversquare design (larger bore than stroke) and that you state that the engine's stroke of
less than 3 inches contributes to its smoothness. I've been wondering if an oversquare
design has a higher thermal efficiency than an engine with a lower bore/stroke ratio. Do you
know if this is generally the case? To me it would seem to be for reasons such as:
the BMEP remaining higher for a greater proportion of the engine's stroke,
mechanical losses would be less because piston speed as a function of crankshaft speed
would be lower, and
because the piston area to circumfrence ratio would be higher leading to lower leakage of
BMEP past the compression rings.
| If you can would you be able to confirm these ideas or put me straight if incorrect.
Any assistance will be greatly appreciated. Regards,
| | Andrew Patmore, Melbourne, Australia, patmore@tpg.com.au
| | Reply from WW:
| | Your questions indicate that you have an engineer's perspective on engines. Very rarely do we
get such in depth technical questions. While there are many things in life I do not know much
about, I can honestly say to you I have an unusually good background in the fundamentals of
physics, chemistry and thermo. This combined with my practical observation and many, many
years of reading and learning from people far smarter than myself have given me a good
background from which to discuss these things.
| | The main issue that you need to look at in motors is not bore and stroke, but rather
the stroke to rod length ratio. Most automotive engines in America have a 1.65 to 1.75 ratio.
When this ratio gets better, like toward 2:1, the piston has dramatically more dwell time at
TDC. This is where really thermally efficient engines start. The down side is the piston is
subjected to more brutal accelerations and decelerations. Many people look at average piston
speed, but this is a meaningless number. The real issue is how steep the acceleration curve is.
This is the real limit. The Corvair's rod length is about 4 3/4". Its rod ratio is 1.62:1,
average for a car engine. In production engines, you'll notice diesel engines are the opposite
extreme.
| | You talk about a number of variables. If we were to change just one on the motor, you
could easily discuss or evaluate its effect. Engines with a bore and stroke combination that
produces the least surface area tend to lose less heat. This tends to favor square engines.
Most people mistakenly believe that given engines of equal displacement, long stroke motors
somehow produce more power, but testing reveals this is rarely so. Probably the reason most
people believe this is ram tuning leading to higher volumetric efficiency requires less
homework for the designer on a long stroke engine.
| | Subj: Learning what's not in the book
| | Date: 4/22/03
Thank you again for your reply to the Florida Pietenpol for Sale.
| | I am an ag pilot with well over 1000 hours. I have always followed the "standard" carb heat procedures without any problems.
But I did not really understand the mechanics of what was taking place, because it was never explained. This rather makes
me wonder if my instructors knew. Your article regarding carb icing is a real eye opener and will go with me and will be taught
in all future flights.
That is one of the many reasons I wish to be a Sport Pilot Instructor. An old ag pilot told me one time, "Son, learn what is
not in the Book if you want to stay alive."
Have a great day,
| | Benny Clark Sr., Pietenpol, Texas, texaswings@cox-internet.com
| | Reply from WW:
| | Thank you for your complimentary comments. I believe your observation on the average
instructor's understanding of carb icing is quite correct. While I was fortunate enough to have
a flight instructor who understood technical issues like carb ice, I feel that there are probably
many instructors who may be good pilots but don't really understand physics and chemistry.
This is why Grace Ellen took the time to write the article, posted on my flycorvair.com Web site
at Carb Ice. I think your instructor's thought on
learning what's not in the book is very good advice. One of Grace's flight instructors always
said, "Your pilot's license is a license to learn, not the end of your education." ... Solid advice.
| | Subj: Zenith 701
| | Date: 4/21/03
I just purchased your Manual mostly because of curiosity, but I'll think of
it more as an investment. I plan to put a Corvair on a STOL 701 (Version 4
- 1,100 lbs. gross) mainly because I see a lot of them with the SOOB power
(pretty heavy when it is all added up).
| | I know I am going into uncharted territory - but this IS experimental
aviation isn't it? Look forward to the delivery of the Manual.
| | Martin Bima, Zenith STOL 701, Winnipeg, Canada, mbima@hydro.mb.ca
| | Reply from WW:
| | This year at Sun 'N Fun, Zenith announced that engines the weight of an O-200, EA-81 or
a Corvair are
acceptable on a 701. They may have some firewall beef-up in mind, but they told a number of
701 builders that the
Corvair would be acceptable. Keep in mind when dealing with Zenith that the only time they use
the term "approved" with an engine is
when they have personal flight experience with it. Until we're at that point, I just tell
people the Corvair is within Zenith's
weight and horsepower requirements. In the future, I think this will be a very popular engine
combination. Previously, Zenair
would tell us they wanted no more than 200lbs. firewall forward and I must have had 200
people ask me about this in light of
seeing O-200s and Subarus on the 701.
| | Subj: Florida Pietenpol for Sale
| | Date: 4/20/03
I am really confused.
I am considering purchasing a Pietenpol located in Florida.
The owner I am convinced is an honest person and has suggested that he would not fly the Pietenpol from Florida to Texas.
He is not comfortable with the engine since some of his friends had an engine failure from carburetor ice and almost got killed.
From the information on your home page, maybe pre-judging from others' bad experience is not the best thing, although the
engine is direct drive. It has a static run up of 2600 to 2700 with a propeller designed to accomplish this RPM. And I am told
this propeller and RPM will produce some 100 to 110 HP.
Would you be kind enough to council me in my dilemma as to what to do???
Have a great Day,
| | Benny J Clark Sr., Pietenpol, Texas, texaswings@cox-internet.com
| | Reply from WW:
| | I suspect you have been dealing with a man named Joseph Vince, who also calls himself
"The Reverend Joe." Unfortunately, he is not an honest person. Nor is he a friend or associate
of mine, and he did not convert his Corvair according to my Conversion Manual. I have personally
inspected his aircraft, and can assure you that it has numerous structural deviations from
B.H. Pietenpol's plans. I have seen the aircraft advertised on the Internet, and would only
wish that it not bring tragedy into someone's life. Joseph Vince's engine was built out of
junk parts with a very low level of knowledge, craftsmanship and care. The fact the engine
failed on its first flight came as no surprise to people who had seen the aircraft in person.
The real surprise was that Joseph, who purports to be a man of God, would talk someone else
into flying the plane for him. I bear no malice against this person, but I cannot understand
his actions, and I know aviation, the passion of my life, does not need another black eye.
| | Under no circumstances should anyone purchase either Vince's "Pietenpol" or his
"engine." Neither are airworthy for a multitude of reasons.
| | I did get seriously injured while riding in my Pietenpol as a passenger. After the
engine went out due to carburetor ice, the pilot spun the plane in from about 80'. The full
story is on www.flycorvair.com at the page titled Carb Ice. Following the number one rule of FLY THE PLANE,
would have prevented this, as would have checking the weather, pulling on the carb heat knob
which was located at only the pilot's controls, installing a carb heat knob in the front
cockpit, being more selective about who I let fly the plane, etc. As long as you are a diligent
pilot, this kind of accident will never happen to you.
| | My standard suggestion is convert the engine yourself according to my Conversion Manual,
build the plane yourself according to Bernie Pietenpol's plans, and learn to fly for
yourself with
a competent instructor. You
will enjoy both peace of mind and pride in workmanship if you trust in and rely upon yourself,
and ask questions without hesitation when you need a little extra help.
| | Subj: Corvair Fuel Pump
| | Date: 4/19/03
I visited your
Corvair presentation at Sun 'N Fun. Do you know that there is an AD note on all Franklin engines using the
diaphragm type fuel pump? This happens to be the same fuel pump used on the Corvair motors. I don't know what the
replacment would be as it didn't specify in the AD. I haven't had any trouble with the one in my Corvair. What's your take on
this.?
| | Bob ODell, Panacea, Fla., Lledobob@aol.com
| | Reply from WW:
| | You are quite correct that certified Franklin motors were delivered from the factory
with Corvair fuel pumps. Several years ago, there was a fatal accident in Texas in a Franklin
powered Swift that utilized this fuel pump (I am pretty sure there has never been a fatal
accident in a Corvair powered aircraft). You can read the accident report on the Web at
www.faa.gov, and there are a number of other factors involved besides the fuel pump.
Franklin engines are made in Poland, and the American fuel pump manufacturer may have been a
more tepmting litigation target. As a result of a lot of litigation, etc., there is now
an AD. So that everyone understands, ADs only apply to certified aircraft. My personal
experience with Corvair fuel pumps is that they are reliable and when they quit, they give fair
warning. If they have been less than reliable in Franklin engines, it probably has something to
do with that installation or perhaps their overworking it to feed a 220hp engine. I would not
be very concerned about using it in its stock Corvair application.
| | Subj: Parts
| | Date: 4/18/03
We’re finally getting around to building our engine and need a few parts. The guy we bought the engine from did a great job except
that he spent a lot of time putting a magneto on it. I’m not sure why he didn’t get the
performance out of it that he expected:)
We need the rear housing, oil filter adapter plate, by-pass valves and one of your dual ignition distributors. What all comes with the
distributor - cap, rotor, re-curving?
Know anyone who wants a magneto for their Corvair engine?
| | I have to warn you, dad met you about a year ago in North West Florida at a small EAA fly-in. He says that he has
several questions for you??? Should be interesting.
| | I’m building a Vision and stopped by in November to see Steve. We walked all the way over to your place but you were out,
sorry I missed you.
Thanks,
| | Brian, Vision, brianyoung@charter.net
| | Reply from WW:
| | Sorry we missed you. We spend about 100 days a year on the road. If anyone is planning on
a visit, please call in advance. We've had hundreds of visitors to the hangar over the years, and
you're always welcome.
| | Undoubtedly we met your Dad at the Quincy Fly-In near Tallahassee, Fla. We had a great time
there, and there were a lot of very mechanically clever guys, typical of many rural areas in
America. Certainly e-mail any questions your father has.
Since you have my Manual, you know my experience and opinion with magnetos (great for certified
motors, not appropriate for Corvairs). Please note that my dual ignition distributors are now
completely re-manufactured in house and contain everything from the bottom of the shaft to the top
of the cap. You need only send us your old core and a check for $219 payable to William Wynne,
210-11 Cessna Blvd., Port Orange, FL 32128 (add $15 for international S&H, including CANADA).
These are also available by credit card via PayPal at the Online
Catalog.
| | Subj: Corvair in Merlin
| | Date: 4/17/03
I'm looking at purchasing a Merlin kit (without Rotax) & have been eyeballing the Corvair. Do you know of anyone who has
used the Corvair in a Merlin?
| | Doug Baird, DBaird@barroncollier.com
| | Reply from WW:
| | I do not know of anybody who has used a Corvair in a Merlin. The Merlin is a fairly
efficient airframe in its class, and reported to be a very sturdy design. The Corvair has
very successfully powered a number of aircraft in the Merlin-size category that were substantially
less efficient. If you can get a report from somebody flying a Merlin on an O-200, this would give
you a good indication of its performance with a Corvair.
| | Subj: Engine for Zodiac 601HDS
| | Date: 4/16/03
I have finished most of the airframe on my Zodiac and am looking
for an engine. I bought a Subaru EA81 at a junkyard, but after looking at
the cost of a PSRU and other expenses to get ready, I am about to change my
mind. I am interested in a Corvair and thought I would check the
availability of one in my area (Western Kentucky) but wanted to ask your
opinion on which engine would be best suited for the 601, a 164 or 190? If
I go this route I'm sure I will be buying your Manual and some parts.
Thanks for your help.
| | Mark Sandidge, Zodiac, Madisonville, Ky., MSandidge@PeabodyEnergy.com
| | Reply from WW:
| | Thank you for going ahead and buying the Manual. While your questions will be answered
in the Manual, available for $59USD in the U.S.
by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or
by credit card via PayPal at The Online Catalog (please add $15
for international S&H, including CANADA), let me share the answers with other readers of the
Web site. While I am emotionally biased toward American products like the Corvair, the factual
numbers bear out that the Corvair, even the standard 164cid power plant, will be a better power plant
for your 601 than the EA-81, even with an expensive PSRU. My opinion on this is based on
replacing flying Subarus with Corvair engines in two KRs and a Stits Skycoupe last year.
The KRs were much lighter with direct drive Corvairs, and had better performance with far more
conservative use of the engine. Notably, each of these engines was built for less money than
the PSRU cost for their respective EA-81s. Corvairs can be found in every part of America. Most
guys spend less than a week looking for one after they decide to build.
| | I'm working with a number of 601 builders to produce drawings and parts to make your
engine installation simpler. This is high priority for me, and you can expect to see things
like the motor mount soon.
| | The direct drive, air cooled simplicity of the Corvair is much more complementary to
the 601, which has the same values of simplicity and reliability.
| | Subj: Piet Corvair
| | Date: 4/15/03
I am just starting a Piet (ribs built, moving on), and I am interested in a
Corvair for power. When is the next "Corvair College" scheduled? And are
previous "College" pictures, tapes or whatever available?
| | Daniel Bailey, Pietenpol, EAA 96269, Chapter 868, Olathe, Kansas, dbceltic@micoks.net
| | Reply from WW:
| | We just had Corvair College #4 at Sun 'N Fun 2003. At this College, I introduced the
first tape in my engine building series. It is available for $29USD in the U.S.
by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or
by credit card via PayPal at The Online Catalog (please add $15
for international S&H, including CANADA).
The second tape in the series is being edited now,
and the third will be done by Oshkosh. While I'll be speaking at Brodhead and Oshkosh this summer,
I have no firm plans to hold a College at either location. I have traveled to Kansas several
times to promote the Corvair motor. In the past, we've attended the Tandem Wing Fly-In in Ottawa,
Kansas, and demo pilot Arnold Holmes operated my Pietenpol out of Gardner, Kansas, for a month in the
Fall of 2000. Perhaps you remember seeing it.
| | The Corvair and the Pietenpol are a natural
combination. Remember, it was the specified choice of Bernie Pietenpol.
| | Subj: Corvair forums at Oshkosh
| | Date: 4/14/03
I had met you at Sun 'N Fun but hadn't attended your rebuild sessions. I'm wondering if you're going to be at Oshkosh this
year. Please let me know. THANKS.
| | John, jcl64@a-znet.com
| | Reply from WW:
| | I will be giving forums at Oshkosh 2003 for my second year in a row. Check back at the
AirVenture 2003 Forums Page and
the News from the Corvair Authority Page on flycorvair.com for
the schedule as it becomes available.
| | Subj: WOT Fuel Flow
| | Date: 4/13/03
Have you tested a Corvair to run all day wide open, 3200RPMs? What is the fuel flow on the big O-190 WOT? Has anyone ever put
fuel injection on these? It seems like a good idea fuel injected since the need for a fuel pump on my plane is already there.
| | Justin, jmw116@socal.rr.com
| | Reply from WW:
| | The longest length of time I've operated a Corvair motor at WOT was 2 1/2 hours at
4500rpm. After a 5 minute break to refuel, it did another two hours at the same output. The
Corvair motor ran at more than 3200rpm at highway speed in the original car. The engine is not
bothered by any rpm that you would find useful in a direct drive engine. Fuel flow at any power
setting is directly related to the amount of power developed. A Corvair motor, like almost all others,
burns .5 pounds of fuel per horsepower per hour. Thus, 100hp continuous output would be 50lbs. of
fuel, which is 8.3 gallons per hour. Please note that very few aircraft engines, even certified
ones, are operated at WOT all day long.
| | I have done work on some of the most sophisticated aircraft in sport aviation. I have
experience with the fuel injection systems on these engines and it is my opinion from experience
that virtually all homebuilders would be better served with a carburetor. Fuel injection is covered
in several pages in my Conversion Manual, available for $59USD in the U.S.
by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or
by credit card via PayPal at The Online Catalog (please add $15
for international S&H, including CANADA). In short, the claims of great fuel savings will never
materialize, and the complicated electronics, their high power consumption, single point
failure modes, 35psi fuel systems, etc. are an entirely different category of aviation risk
management. If you really want to go flying, build what experience has shown to work and let
craftsmanship be your personal mark on your aircraft.
| | Subj: Getting Started - EAA Experimenter March 2003
| | Date: 4/12/03
I just wanted to thank you for writing the article, "Making the Decision to
Build Isn't Easy or Rational," in the March 2003 issue of EAA's
Experimenter magazine.
| | For several years I have been "struggling" with all the reasons why I wanted
to build an aircraft, and also, with equally valid reasons why not to. I,
too, had been trying to "rationalize" my feelings towards this project and
getting nowhere. Not being able to verbalize my feelings to my family and
friends did nothing to help my cause. After reading your article, I
immediately understood that my reasons for building were more deep-seated
than I had originally thought.
| | I have just returned from Sun 'N Fun. There, while speaking to homebuilders
about their projects, I couldn't help but notice similarities in their
expressions and passion in their voices when they spoke about the "building
process." I will assume, since the results of their labor was sitting right
in front of us, they used this passion to see them through to completion.
Another common thread was the pride they felt when they took flight in their
labor of love. Frequently, they would punctuate their sentences with phrases
like, " . . . I've never regretted it . . .," or ". . . this is my lifetime
achievement . . . ".
| | Your article helped me understand that my passion to build is tied more to a
combination of my love of flying and my need for a creativity outlet rather
than simply the need for an aircraft. I've removed the "no rational reason
to build" entry from the "minus column" and happily added the entry "outlet
for creativity" into the "plus column."
| | Thanks again for a great article.
Best regards,
| | Stuart Heitshusen, Schenectady, N.Y.
| | Reply from WW:
| | Thank you very much for your kind words about my column in the Experimenter.
Mary Jones, the editor, asked me to write a continuing column specifically aimed at the person
who is a first time builder, just like you. Her request reflects EAA HQ's emphasis on including
all people in homebuilding, not just the most financially fortunate. I tried to address the most
common concerns and issues which first time builders face, for I myself went through this process
just like you.
| | Subj: Engine Block Suffixes
| | Date: 4/11/03
I spoke with you at Sun-N-Fun (with about a million other people!) and got your Conversion Manual. I have obtained enough parts to start
building an airworthy engine BUT...my block has suffix letters RN. This is not posted in your book and I am wondering if I
have a good block? Incidentally, the guy I bought the pieces from showed me a factory publication and there are a LOT of
designations that aren't reflected in your Conversion Manual. It's probably not a big deal, but I rely on your experience and this
one is a stumper.
| | Larry, lnawms@msn.com
| | Reply from WW:
| | Your RN motor is a 1965-66 140hp Powerglide equipped engine. The only parts of this
engine which are not suitable for use on your conversion are the cylinder heads and the 4 degree
retarded crank gear. The good news is that the crank gear can be replaced with a new one for about
$85, and the cylinder heads are worth up to $300 for the pair to a car guy. The much more
common 110 cylinder heads are the ones you want. They are much cheaper, and will bolt right on to
your cylinders. Other than this situation, which precludes its inclusion in the Conversion
Manual, your motor is an excellent core.
| | Subj: Carburetors
| | Date: 4/10/03
In your Conversion Manual, you speak of MA-3 and MA-3SPA carbs costing upwards of $500. In my search so far I have been
unable to find one for even close to this price. Where have you seen such prices?
| | Gordon Alexander, Shakopee, Minn., gordon@curio.com
| | Reply from WW:
| | At Sun 'N Fun I saw 20 of these carburetors for sale for less than $350. The Fly Mart
had a shelf of them with an average price of $300. These are very common carburetors, as they
were original equipment on O-200s. $300-$350 is fair for a good working one with a metal float
(MF will be stamped on the data plate). I would pay $500-$700 for an overhauled one as long as
it came with a yellow tag from a repair station. I've also purchased them off eBay and
Barnstormers.com.
| | Subj: Zenith 601XL Engine Costs
| | Date: 4/9/03
Am about to build a Zenith 60XL and am very seriously considering engines. I have 2 engines sitting, a 110 and a 140 hp.
Are any currently flying on the 601? Could you get me in touch with the builder? Am also curious if you would be willing to
supply me with cost for a conversion that I might do and give me a cost for you to build to 120
hp with electric start, 20 amp
alternator, dual ignition, starter solenoid, exhaust... and let me know about engine sensors that you might think useful... I'm
looking for a bullet proof and reliable engine with a long life... Thanks,
| | Jim, Zenith 601XL, jdankochiro@yahoo.com
| | Reply from WW:
| | The 601 and the Corvair are a very good match. A number of people are working on it
right now, and we're helping them develop the installation, but no one has flown the combination
yet. Considering the engine's success in other airframes, no one should have any doubt that it
will produce a very economical and useful engine option for the 601.
| | As for your request for a price quote on a motor, all of my work in the past 8 years has
been primarily in the area of teaching people how to build their own motors. Although I have
built many, many motors, the primary aim of my work is to help homebuilders by the original EAA
motto of "Learn, Build and Fly." Your typical Corvair conversion costs $2,500 to $3,000 complete.
A large displacement motor like the one you mention would be more than enough power for the
most ambitious aims of the 601. The parts to build such a motor would be worth something in the
range of $4,000. If I were to build such a motor, and supply it with every bracket painted, every
piece of safety wire in place, etc., it would become much more expensive than the bare parts
would cost you. I'm a very skilled A&P mechanic, and around here, we can bill our time for a
fair rate. More importantly, in the length of time it would take me to build your motor, I could
help half a dozen guys build their own, answer a few dozen e-mails, write a magazine article,
make a housecall to a guy who's ready to fly, and speak to an EAA Chapter or two. Years ago, I
was very thankful to anyone in aviation who wanted to take the time to teach me something. These
days, given the option, I will always choose to spend my time teaching and sharing. Aviation
already has too many expensive engines for people with thick wallets. I would much rather have
you be one of the six people who comes away with the positive experience of saying "I built my
own motor, learned a lot, saved a bundle, and have a real experience to be proud of."
| | Subj: 1/2 Corvair! Is This Possible?
| | Date: 4/8/03
I saw a 3 cylinder 1/2 Corvair in a 1978 Sport Aviation. Is this a hoax? Would it really run?
| | Micheal J. Fox RN, BSN (Not the Actor), foxyrn@usa.net
| | Reply from WW:
| | The 1/2 'Vair is not a hoax, but it doesn't work either. As you may guess, I
found it in a Corvair car collection about 7 years ago. It was built less
than 10 miles from here. The engine had to be the work of two people: one
good, the other a hack. But neither of them knew much about balancing motors either.
It would run very, very rough. It would also have 70% of the weight
and 50% of the power of a full one. Sure does look nice though; it is a more
appealing shape than a 1/2 VW. But it will not work because the opposed motor
counts on the mass of the piston and rod on the other cylinder for balance.
| | Subj: New Video
| | Date: 4/7/03
William and Grace Ellen,
| | I received the new video on Friday, but the ice storm in the Detroit area
kept our power off until late Saturday. I found the video very
helpful in understanding how a Corvair motor goes together. There are so
many differences between a flat engine and that of a standard V
configuration. They say a picture (or video) is worth a thousand words,
and it's true. I've read the Chevy manual and Finch's book, but it was
William that took me through the steps required to assemble the short
block. Now I understand! Great job!
| | I have just joined the local Corvair car club and am making the contacts
required to locate the correct engine. Will there be an "Engine Assembly
Part 2" video? I plan to attend Oshkosh this year and my first stop is to
buy both of you a couple of beers. Unless, of course, William would prefer
something with an umbrella in it! :-) Just kidding!
Thanks for all your help,
| | Jim Burt, Manual #5301, jim.burt@gm.com
| | Reply from WW:
| | Thank you for the nice words about the Engine Assembly Part I Video. We have these
readily available for $29USD
by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or
by credit card via PayPal at The Online Catalog (please add $15
for international S&H, including CANADA).
| | Although we just introduced these three weeks ago, a lot of positive comments like yours
have come back. We have already filmed Part II, and it will be available next month. Part II is pistons,
cylinders, rings, rod bearings, etc. Part III, which is only scripted at this point, is going to
be the cylinder head and valve train video. These will be done for Oshkosh. We also are kicking
around the idea of an engine teardown video starring Grace Ellen. If you have other ideas of
what you'd like to see, please let us know.
| | We'll definitely be at Oshkosh, and we'll definitely take you up on your offer. Watch
the EAA AirVenture 2003 Forums Page and News from
for the Corvair Authority Page on flycorvair.com for the forum schedule as it becomes available.
| | Subj: Corvair Head Numbers
| | Date: 4/6/03
I recieved your Manual and video this week and have been
pouring over it! I have 3 blocks: 1 with a ZF code, and 2
with the YC code. According to the Manual, these are the 95
hp engines. The head numbers I have been able to read are
not on your list. They are 3813516, 3813513, 3786589 and
3786752. Will I be able to use any of these heads in my
Pietenpol? I'm looking forward to getting started on my
projects and enjoyed your presentation last summer at
Brodhead. Maybe I'll see you there again some time.
Thanks,
| | Dale Haag, Pietenpol, West St. Paul, Minn., haagc@uswest.net
| | Reply from WW:
| | The engine letter codes you mention could either be an acceptable motor or non-acceptable
motor. Letter codes like ZF and YC are only acceptable when the motor is a 1964 model. These
same letter codes were also used on earlier engines. Your cylinder head numbers are all from
early engines, so I suspect that your engines may be short stroke engines. A careful review of
the Conversion Manual will show you that you need to check the crankshaft for the 8409 stamping.
The head numbers you mention are not listed in the Manual because they are not acceptable. If your
crankshafts have any number other than 8409, they are unacceptable.
| | Thank you for the kind words about Brodhead. We're looking forward to going back
this year.
| | Subj: Midget Mustang Corvair
| | Date: 4/5/03
How does the Midget Mustang fair with a Corvair conversion?
| | Dennis Lithgow, Midget Mustang, denbeclithgow@juno.com
| | Reply from WW:
| | The Midget Mustang is a beautiful and also highly efficient airframe. Our friend Paul,
who's at our home airport of Spruce Creek, is working on this same combination. I've studied
the horsepower requirements, firewall size and shape, and the standard cowling, and feel it would
be a good match. We have a dummy engine in Paul's cowl now, and are working on a motor mount for
him. Watch www.flycorvair.com for details.
| | Subj: Static vs. WOT RPM
| | Date: 4/4/03
What kind of increase in RPM do you see between static and full throttle level fight? Say that 72" Warp Drive prop on the ground run
2650rpm, what would we see in the air on say my gyro? Or what did you see with the 68" Warp Drive on the Pietenpol?
| | Brent Brown, Autogyro, Fayetteville, N.C.
| | Reply from WW:
| | A Warp Drive with the correct pitch setting for cruising at 85mph will turn an extra
150rpm or so in level flight over what it did on the ground. If the airspeed was, say, 150mph, I
believe the difference would be substantially greater. The longer Warp Drive props will flex
somewhat in operation and contribute toward smaller rpm variations.
| | Subj: Rear Mounted Starter Kit
| | Date: 4/3/03
What is the estimated cost of a rear mounted starter kit?
Thanks!
| | Clint Courtney, Troy, Mo., can3g@aol.com
| | Reply from WW:
| | Here's a brief history of starters on Corvairs. Prior to my work, virtually all Corvair
motors were hand prop. Eight years ago, I developed a front starter setup and sold parts and plans
for it. About four years ago, there was talk of developing rear starters. As far as I know, I was
the first one to fly one on the back of the motor and fully investigate all of the oil system
modifications, etc. After having built and flown several versions of each system, it is my opinion
that my current generation of front starter systems is the better way to go. Most of the people
interested in the front starter system simply say, "Good, I like it. Show me how to make it or
sell me one." Conversely, most of the guys working with rear starter setups all want me to
change the design or modify it slightly to fit each of their individual aircraft or separate
needs. Thus, it's not economical for me to produce parts for rear starter systems.
| | The Conversion Manual, available for $59USD in the U.S.
by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or
by credit card via PayPal at The Online Catalog (please add $15
for international S&H, including CANADA),
contains the complete story for starters at both ends along with my complete experience developing
and flying both. But, I only offer parts for front starters, and the complete story on my latest
update on front starters, including simplified bracketry and much lower profile, is included in
the Spring 2003 edition of The Corvair Flyer newsletter. Annual subscriptions are available for $20USD
in the U.S. by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL
32129-0802, or by credit card via PayPal at The Online Catalog
(please add $5 for international S&H, including CANADA).
| | Subj: Corvair for Europa
| | Date: 4/2/03
I am building a Europa XS, it needs about 120hp for T/O with a FWF of
200lbs approx. Do you know of any Europa builders using the Corvair? The
single ignition worries me, can dual plugs be fitted to the heads, and
maybe a magneto to fire them, or even the HEI from the Chevy V6? Is the
3100cc engine not as reliable as the 2700cc version, if not then why use
the smaller engine for the same weight? I believe that the max bore is
94mm - can the engine be stroked for more cc? I have used 100mm cyls in a
Type 4 VW - has anyone tried these in a Corvair? I'm seriously looking at
the Corvair for my Europa, and your engine conversion looks a strong
contender. The requested info, and any comments would help me decide.
Thank you in advance,
| | Dave McCandless, Europa, daval@iprimus.com.au
| | Reply from WW:
| | You certainly take the award for packing the most questions into a single e-mail.
All of your questions are answered in depth in the Conversion Manual, available for $59USD in the U.S.
by check or money order payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or
by credit card via PayPal at The Online Catalog (please add $15
for international S&H, including CANADA).
| | But let me give you a quick overview. 3100cc Corvairs cost about $800 more to build than 2700cc
Corvairs. Additionally, they take a little more care and require a better than average core
motor to begin with. The reason why 95% of Corvair builders are going with the 2700cc motor is
that it makes excellent power very economically.
| | Corvairs can be stroked and bored beyond 3100cc, but this requires extremely extensive
machine work, and it would be much simpler and probably less expensive to go with another type
of motor, especially since you're in Australia.
| | On your ignition worries, my dual ignition system with single sparkplugs has been proven
in hundreds of hours of flight use. My aircraft's first 300 hours of operation were with dual plugs
with one set driven by a magneto. Dual plugs is a worthless modification of the Corvair cylinder
head, which causes an unnecessary loss of cooling fins. In hundreds of hours of flying Corvair
motors on a variety of fuels, I have never fouled a sparkplug. This is very likely due to the
fact that the Corvair does not leak oil into the cylinders, has a very strong spark at idle (unlike
a magneto) and it has high enough compression to have efficient combustion. As for reliability,
electronic ignition systems like the HEI work great for a long time, but fail without warning.
Although points will not last as long, they almost always give plenty of warning. This alone
makes them superior. Anyone who is critical of points ignition should realize that all aircraft
magnetos have points inside.
| | Several years ago, Europa Aircraft claimed their aircraft would do 200mph on an 80hp engine.
The most modest Corvair motor can easily exceed this at very conservative rpm.
| | Les VanMeter of Chino, Calif., is our leading Corvair/Europa builder. Perhaps you can
contact Les through the Europa builders network.
| | Subj: Cabin Heat
| | Date: 4/1/03
I have a quick question: Is it an easy matter to install heat into the
cockpit with the Corvair engine? Maybe thru the oil cooler? I have have not
ordered your book but plan to right after April 15th. Thank you.
| | Mike, gbgroupmike@hotmail.com
| | Reply from WW:
| | The issue with oil for cockpit heat is this: When the weather gets cold enough that you
would need cockpit heat, the oil cooler no longer runs hot enough for a good supply. A cabin
heat muff off the exhaust system would be the best way to go. Just make sure you have a very
good exhaust system and a CO detector inside the plane. Virtually all certified aircraft are done
this way, and with good annual inspections, it is a safe system.
| | Subj: Stock Linkage
| | Date: 3/31/03
In all of your travels and purchases, do you run across 140 stock linkage? I
am looking for a useable set. From reading your info, it looks like you go
to a different induction system. Can you help?
Thank You
| | Wade Williams, Wade@DRC-ENG.com
| | Reply from WW:
| | My friend Kevin and I own a number of Corvair automobiles. The one characteristic they
have in common is that they are all 140 powered. Even Kevin's shortened 1962 Monza convertible
has a 140 Powerglide setup in it. When we come across good 140 stuff, we tend to put it to good
use ourselves. The carburetor linkage, as you know, is much rarer than the heads. Perhaps
someone reading this on the Q&A Page could help you out? Hope it works out for you.
| | Subj: Pietenpol Update
| | Date: 3/30/03
Just a note to update the Pietenpol Corvair rebuild. We are at the cooling duct stage and had them
all fabricated when we discovered there was very little access to the spark plugs so started to
make access doors with Hartwell latches.This failed because the material was too light and they
wouldn't close tightly. We solved the problem by fastening the covers with P K screws. Also making
cowling openings bigger with a duct tube from the center to the oil cooler on the firewall. Note:
Old distributor to be used for pre-oiling and all the clutter in our shop. An old mechanic told me
one time that you could tell if the work was getting done by how the shop looked. If it was squeaky
clean they weren't doing anything. The weather will govern the installation on the airframe but we
are almost ready. More later if you like.
| | Ray and Rich Hill, Pietenpol, Baxter, Iowa, raydot@pcpartner.net
| | Reply from WW:
| | Thank you for the update. Yes, please make sure you send us more pictures as it comes along. Sometimes
the simplest solution, i.e. PK screws, is the best.
| | Subj: Pegazair on Floats
| | Date: 3/29/03
I received and read your Conversion Manual yesterday. Thank you. After reading that and several of the other builders' Web sites,
I have found that I'd like to spend the money and have the 3,100cc modification. I say this because the
weight and power advantages are worth the $1,500 to me. I also have come to see the light about going direct drive. Other features
I find appealing are: no blower, the OT-10 Cam, your oil pan, a snap ring retainer if possible, a Supertrap muffler if possible,
electric start - probably front, and mounting as large a Warp Drive two blade as you'd recommend.
| | I live on a lake and expect fly my Pegazair on floats. I am not sure the 100LL will often be available. I am willing to spend
up to $100 per further pound saved on my engine installation if you have any recommendations on how to do this. I may also wish to
try an inflight adjustable propellor at some later date, so anything I can do to help accommodate this would also be of interest to me.
Is this a reasonable path? Do you have any further suggestions?
Thanks again,
| | Gordon Alexander, Pegazair, Shakopee, Minn., gordon@curio.com
| | Reply from WW:
| | I've recently tested 2-blade 72" Warp Drive props, the largest diameter they make. I have very accurate hydraulic
thrust testing equipment, and the motor on the test stand was able to pull 385lbs. of thrust at 2,650rpm. Notably, the prop
wasn't that loud. While 385lbs. may not sound as high as some other unobserved claims, keep in mind this is through a muffler
and cast iron exhaust manifolds with no cowl, a blunt air scoop and the 32"x30" firewall on the test stand behind the prop.
This is also a 2700cc motor. I would not be surprised if a 3100 inside a cowl with a less restrictive exhaust system could pull
550lbs. static. A video clip of this test is on my current video tape, Corvair Engine Assembly Part I, available for $29 in the U.S. at the
Online Catalog, or by check or money order payable in USD to William Wynne, P.O. Box
290802, Port Orange, FL 32129-0802 (add $15 for international S&H, including Canada).
| | Your engine proposal seems well thought out and straightforward. I'll be glad to help you out with the
conversion parts as you need them.
| | Subj: Best Day for Sun 'N Fun?
| | Date: 3/28/03
I plan to attend one day at this year's Corvair College at Sun 'N Fun [full schedule at News From
The Corvair Authority]. I have my engine prepped and I think it's ready for
assembly. What day of the week do you think would be best for you? I would also like to know if you got the new top plates
in and how much they are priced for. Thank you,
| | Larry Hudson, indyannie_1999@yahoo.com
| | Reply from WW:
| | I'd say hit the ground running opening day, April 2. Thursday, April 3, probably will
be a good day, too. Look for the crowds to really start rolling in Friday. With this year being
the Centennial of Flight, crowds of up to 1 million are expected at Sun 'N Fun.
| | The new top plates are done and beautiful from the hydro-cutter. We have about a dozen
left at the introductory price of $59. You can see yourself in the polished versions, but
they're very versatile as you also can paint them or emblazen them with your own personal logo.
I couldn't be happier with the final product - it was well worth the wait.
| | Subj: Hello
| | Date: 3/27/03
I just thought I would update you on my KR. The stub wings are complete as is almost everything else on the fuselage. I do have to
make a rudder and elevator to finish the fuselage. Oh yeah, a cowl too. I have reinstalled the Corvair engine for the last time (I hope).
I have also fabricated and installed an air scoop so I can get some serious run time in on the engine. I plan to put a lot of time on
the engine this coming weekend as the temps here will be hovering around 50 degrees. Who knows, I just might put fluid in the
brake system and go taxiing out in the cul-de-sac. Wouldn't that raise some of the neighbors' eyebrows! It is time to get some more
serious building done so I can be airborne by next fall. That is my goal. I will be at SnF on Saturday the 5th and will see you there.
| | Mark Jones, KR2S
N886MJ, Wales, Wisc., flykr2s@wi.rr.com
| | Reply from WW:
| | Thank you for the great progress report. This is the kind of news that gets guys motivated
to get going in their workshops and build. You have come a long way since we visited
your place last summer, and we're just as proud as you are, if that's possible. If you take to
taxiing the streets of Wales, be sure you have a photo crew following you. You don't get to see
that every day. Please bring all the photos you can to Sun 'N Fun. Saturday, we start out at the
Engine Building Tent at 9 a.m., move to the Contact! Forum Tent #3 for William's Corvair
forum 10-11 a.m., then back to the Engine Building Tent. I believe the night airshow is Saturday,
so you picked a good day to get to Sun 'N Fun. We're all looking forward to seeing you there. Have
a safe trip. Grace Ellen.
| | Subj: Wrong engine
| | Date: 3/26/03
I purchased a 110HP engine with the wrong letter suffix (RW). Are any of these engine parts usuable? I only paid $75.00,
so it seemed worth it just in case. This is a running engine. Thanks.
| | Tom Wilson Georgetown, Zodiac 601HD (plans), Maine, twilson@clinic.net
| | Reply from WW:
| | Your motor, an RW, is a good deal for that price. It is a 1966-68 110 automatic motor.
It had a factory option called AIR (Air Injection Reactor), which is an emissions control system that generally has the
undesirable open-chambered heads. But, all other parts on the motor will be acceptable to rebuild
for flying status.
| | Subj: Corvair conversions for which planes?
| | Date: 3/25/03
I am very much interested in getting myself a small Corvair airplane to fly up north and keep on my own land. However, I need
to find the correct plane for my purposes. I really like all the info you put out on the Corvair engine, especially the part about the
dual points distributor and fuel pump. This is one of the main reasons I considered the Corvair engine. Because my plan is to
also have a back up coil, and also backup electric fuel pump, along with a small plane parachute. Just for added precautions.
But I need a lot of help getting started and need some good advice from you. I would prefer
the plane to hold two average size
people and obtain approximaely 5 or 6 gph, probably 20 gal fuel capacity, and cruise comfortably at 100 mph or thereabouts.
Is all this possible with the Corvair or am I way out of line? I also have to consider the cost of such an adventure, because
funding is out of small wallet. But perhaps you can be of a lot of assistance. Probably just another impossible dream of mine,
but I think it would be fun to try. Thank you for your time, s
ir. Sincerely,
| | Michael T. Burke, St. Lawrence, Mass., Twofirst1@aol.com
| | Reply from WW:
| | There are a number of aircraft that would meet your description. Our friend Dave Vargesko
is building a Wagabond (an experimental PA-17) with a Corvair motor. He will have less than
$8,000 in the completed airplane. He's a fairly good scrounger, but anybody could duplicate his
efforts for $10,000-$11,000. This plane will certainly do 100mph at 5 or 6 gph. Additionally,
since it is a high wing aircraft, it will need no fuel pumps at all. If you fly over
inhospitable terrain, or wish to reduce your risk, you should fly airplanes with stall speeds
below 50mph. There are a number of other designs that would also meet your needs. The EAA's
Aerocrafter guide, available at the EAA's online store at www.eaa.org, is a good place to
start your search. Thank you very much
for the nice words about my work.
| | Subj: Pietenpol Motot Mount
| | Date: 3/24/03
I have been looking at the Manual trying to figure out the motor mount. Could you tell
me some of the dimensions from your Air Camper?
How far out from the firewall were your rear mounting holes? How far down from the top longerons was the bed (or thrustline)? And did you
have to tilt the wing back?
| | Trying not to reinvent the wheel,
Thanks,
| | Malcolm Morrison, morrisons5@adelphia.net
| | Reply from WW:
| | My Pietenpol had the short 1933 fuselage. The cabane struts were vertical. The empty
weight of the plane was 732lbs., measured on electronic scales. It had a full electrical
system, brakes, tailwheel, etc. The distance from the firewall to the rear bolt hole was 15".
If you are building a newer fuselage, this will be several inches less. I highly recommend the
longer fuselage. When my plane was painted orange, the thrust line was in the stock location.
When it was blue and silver, I built a new mount which moved the thrust line up to be in line
with the top longeron. It flew slightly better that way, and I think it looked a lot better.
| | There's a lot of talk in Pietenpol circles about moving the wing back and forth. This
is a dumb idea. With the wing moved forward, remember the landing gear doesn't move, and you're
creating an airplane prone to nose over. With it moved back, you can inadvertently change the
angle of incidence. The preferred method is to build the plane with the correct landing gear/wing
orientation and build the motor mount to give you the correct CG with an appropriately weighted
pilot in his seat. We set this perfectly when I built the second motor mount. With a 150lb.
pilot, the CG was at 15"; with a 300lb. pilot, the CG was at 20". The axels were at the
leading edge of the wing. The plane had excellent ground handling and flew well.
| | Subj: EAA
| | Date: 3/23/03
I just read your article in the February issue of the EAA's Experimenter regarding "Resources for Builders and Pilots," and found it very
informative. Happily, I have several of the essential books, and will look into obtaining the rest.
| | I see that you were president of the EAA Chapter in Daytona Beach. I have just been
accepted into the ACET program at Embry
Riddle for next
January, and will be moving there as soon as I can close on the house I've just bought. I've been a member of EAA for about a year now,
though not terribly active. I mostly just read the magazines and dream about building my own airplane some day. I have one degree from Riddle
already, Air Science, with the associated commercial/multi/intstrument license.
| | I'm looking forward to becoming involved more with EAA and will look you up when I get myself established in Daytona.
Take care,
| | Marty Dudeck, 688380
| | Reply from WW:
| | Definitely look us up when you get to town. We'll be glad to have you over any time
we're in town. Thank you for the kind words. I can't recommend highly enough joining the EAA
and utilizing all its resources for homebuilders, including Experimenter magazine.
| | Subj:
Parts Prices, Hi Tech pistons
| | Date: 3/22/03
I need some parts from you. If you send me the cost of them, I
will get a check in the mail to you. I need an Aluminum Oil Pan, some
Hybrid Studs, a Distributor with the necessary work done, Motor Mount
Tray and Prop Hub. I thought I could have you bring these things to
Sun-n-Fun, but now I don't think I will be able to be there.
| | I have the motor disassembled and partially cleaned up; it is scary to start
ordering parts for the first one you work on. I contacted Clark's with
their c2q form for suggested parts order, but haven't heard back yet.
Their catalog boasts the quality of their Hi-Tech pistons - what do you
think compared to Forged? Thanks,
| | Dick Van Fossen, evanfossen1@juno.com
| | Reply from WW:
| Good to hear from you. The prices you requested for these parts include S&H within the U.S.:
Aluminum Oil Pan: $269
Hybrid Studs: $66
Remanufactured Distributor: $219 plus your old core
Motor Mount Tray and Spools: $149
Prop Hub: $319
| You can send a check or money order payable to William Wynne, P.O. Box 290802, Port Orange,
FL 32129-0802, or pay by credit card via PayPal at the Online Catalog.
| | The 2002 Conversion Manual [$59 in the U.S., also available at the
Online Catalog] contains a detailed dissertation on cast, forged and Clark's Hi Tech pistons.
In brief, we only use forged pistons in flight motors. The qualities that Clark's touts are true
for cars, just not for planes where ultimate strength is our bottom line requirement. I understand
the concern associated with jumping into your first motor. Study the Manual, familiarize yourself
with the parts and don't hesitate to ask questions. We now have a very detailed video on how to assemble
the shortblock. It's 84 minutes long, and we're going to have more in the series to complete
the entire engine assembly.
| | Subj: UP AND RUNNING!!
| | Date: 3/21/03
Happy Happy Joy Joy,
It's running smooth. They just don't run when the distributor isn't installed correctly.
I chewed my nails all day waiting to get home and try the starter one more time.
Two squirts of starting fluid and it came to life. It took care of the clock, pictures, stepladder, and stereo in the garage, but that's a
small price to pay for 10 month's work. You should know it gets a little breezy at 1500 RPM in a small room. Oil is about 40psi at
1000 RPM. I haven't checked the head temp yet, but after the first half hour I could still lay my hand on the valve covers.
Thanks For The Help. I'll Be Back In Touch Very Soon.
| | Jeff Kidwell, Hopewell, W.V., whenboy@shentel.net
| | Reply from WW:
| | Congratulations! You've worked hard for this feeling of satisfaction, and it's all yours.
Looking forward to hearing more good news when you put this engine to work.
| | Subj: Composite Material
| | Date: 3/20/03
Thanks for your hospitality when I drove Steve Megill and the guys up.
I enjoyed talking about your twin engine design and
would like to ask a question.
What is the source for that sandwiched fuselage material?
Thanks again,
| | Dick Ripper , EAA 517011, Lakeland, Fla., rwripper@prodigy.net
| | Reply from WW:
| | Good to hear from you. It's always a pleasure to have Steve around, and we're glad
that you and the gang from EAA Chapter 229 were able to accompany him over for assembly of his
shortblock.
| | I'm answering your question here because I've been getting it a lot since we featured
the "Wynne Twin" in the latest Corvair Flyer newsletter. I'm sorry, but I haven't found another
source for that composite material. I found it at an aircraft surplus store, bought every piece
they had, and only have enough to complete my project with none to spare. Please let us know if you
find another source.
| | Subj: Compression
| | Date: 3/19/03
What is the maximum compression ratio you would recommend for these engines? I was planning on putting a '61 102 HP
head aboard a '65 110 engine. Because of the 49 cc combustion space, the compression ratio would run just over 10:1.
As the C/R increases, so does engine heat, stress and chances of detonation, right?? I could mill out a larger combustion
space or build the shorter-stroke 145 cid engine instead. Any idea how much HP I could expect running an "early" with the
OT-10 (with stock displacement)?? Thanks for any assistance you might give.
| | John, josandt@netzero.com
| | Reply from WW:
| | There are a number of reasons why you would not want to build a 145cid motor. These are
outlined in great detail in the 2002 Conversion Manual, available by credit card via PayPal at
The Online Catalog, or by check or money order for $59USD (add $15 for international S&H,
including Canada) payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802.
The 164cid motors make much better powerplants. While 10:1 could be run on 100ll, I think it is
a much better idea to stay closer to the 9:1 compression that is stock on 164cid powerplants.
There is no real reason to consider putting early heads on a late motor. It requires machine
work and late model heads are readily available.
| | Subj: : Fine tuning
| | Date: 3/18/03
I now have 4 hours of run time on the Vair and just
replaced the Ivo Prop with a 3-blade 54-inch Warp Drive
prop. I set it at 50 pitch. It will run at 2400 rpm
static at that pitch. So I need to tweek things to get
it up to 2800rpm static. I havn't put a light on the
timing yet, but have moved it around a little to see
if there is a difference. I have yet to play with the
advance, but it's presently set at 30 degrees at WOT. I
have put in different needles in the Aerocarb. I can
set it so that it's running very rich (engine starts to
run rough and load up) to the lean side of average.
And there's about 50 degrees difference in egt. Can't
get the 100 degrees that Aerocarb recommends. My egt
runs about 50 degress hotter on the left bank - adjust
the runner length from the carb, maybe? The next thing
that I will test is egt difference of each cylinder on
one bank to see that my mixture distribution is equal.
The engine runs smooth from idle to full throttle and
has very good acceleration, so I'm thinking the cam
timing is ok. My rear seal is leaking like a seive, so
I'm thinking I may have put that seal in backwards. I
put it in from the outside.
| | Del Magsam, "Outlaw Sonex," New Richmond, Wisc., farmerdel@rocketmail.com
| | Reply from WW:
| | Again, congratulations on your running motor. The rear seal leaking is most likely caused
by forgetting to put the oil slinger between the balancer and the distributor drive gear.
It's a simple stamped steel disk, but it keeps oil from being thrown directly on the seal. Yes,
the seal does go in from the outside, and the slinger must be put on before the rear cover goes
on.
| | 30 degrees of timing advance will not ping unless you have very lean mixtures and high
loads. I encourage everyone to use a timing light when doing their initial test runs. When you
adjust your propeller for a higher static rpm, say 2,700-2,800, make sure that your timing stays
within the limits specified in the Conversion Manual. The distributor may have a slight advance
left to go at 2,500.
| | Subj: BD4 as a 2 place w/ Corvair?--Thanks, I'll order Manual
| | Date: 3/17/03
Thanks, yes I've decided the Corvair makes economic sense regardless of which plane I decide on. I may go with the smaller
KR2 or the CH60l Zodiac. Regardless, I will be ordering the Manual.
Thanks again,
| | Steve Mann, 601 or KR2, Rohnert Park, Calif., smann23@netzero.net
| | Reply from WW:
| | Thank you for your order. The Corvair is a versatile powerplant, and can successfully
power many of the useful classic designs of homebuilding. The KR2 and the 601 are good
examples of planes the engine is well matched to.
| | Subj: 95 or 110 Heads?
| | Date: 3/16/03
With a Stromberg MA3 carburetor with the smaller venturi, would it be better to use the 95 or
110 hp heads?
| | Alex Sloan, Greenbriar, Ala., alexms1@bellsouth.net
| | Reply from WW:
| | There is no effective difference in the heads once they are converted according to the Coonversion
Manual, available at The Online Catalog Page. A lot of people worry that starting with a 95 will yield a less powerful motor when
converted. This is not so. The 95 and the 110 have the exact same port and valve sizes. They have a
slight compression difference, nothing significant. From the factory, the main differences were
cams, timing and jetting. Since we change all of these things in the conversion process, either
the 95 or 110 will yield an excellent conversion with perhaps as little as 2hp difference.
| | Subj: Safety Shaft
| | Date: 3/15/03
I purchased a safety shaft from you recently along with an updated version of the Conversion Manual.
My engine is going to have electric start and an alternator.
My question is simple.... which end do I have the machine shop drill and tap the hole for the safety shaft?
Please reply. Machine shop will be getting to my crankshaft and block in the next day or so.
Thanks. Blue Skies, Always,
| | Dave Long, 150pilot@suscom.net
| | Reply from WW:
| | The drawings in the Conversion Manual show that Corvair motors are always driven off the
flywheel end of the engine. Thus, the safety shaft is threaded into the pilot bushing bore.
VW motors are traditionally driven off the pulley end, but Corvair motors are always driven off
the flywheel end.
| | Subj: Corvair Salvage
| | Date: 3/14/03
I am very interested in your view that the country is over-run with Corvair cars and engines.
I am somewhat reluctant to
destroy a restorable car in a junkyard, as a collector will be deprived of just one more
opportunity to do his/her thing after
I leave. Nonetheless, I am scouring around, and in Greeley, Colorado, I have located two cars,
and if I remember, they are both
too early for my use. And the owner in Greeley wants $300 each for his. I located a place in
Denver (south suburb) fairly near
where I live, and several weeks ago the man there told me he had three of them, which he would
sell for $150 each. While I
don't consider three to be a whole lot, I thought I might be satisfied with that. However,
when I went back to make a deal for
the three, it turns out he only has one, a 1965 model, to sell at all. I recall you bought 12
or so for $1000, and I wanted to see
a selection like that so I could really choose a nice one for myself. Frankly, I wanted to buy
three books from you, so I could
restore three (two for me and one for a friend) but now I am unable to do anything of the kind.
I am not a happy camper.
Can you provide any ideas on what I can expect in real life toward getting perhaps a newer
1968 or 1969 model? Am I wrong
to think that a better choice? By the way, this guy does have a 1964 model but I don't know
if that is acceptable.
| | I called a junkyard right in Denver, and he was on his computer (I guess) and he said
he could locate one in Oregon, and one
in Michigan. Is THAT wonderful? $500 each. Plus shipping. These things don't sound plentiful
at all. The guy that has one
here for $150 claims that dealers are NOT hanging on to them as the age gets older. Off to
the melting pot!! That is not going
to help the availability or the price. I do not know WHAT to believe. Can you help??
Yours sincerely,
| | Richard G. Alps, Littleton, Colo., Richardalps@aol.com
| | Reply from WW:
| | Your concerns are unfounded. First, the 1965 motor for $150 right under your nose would
make a great conversion. The motors are not rare. Today in my hangar, a man dropped off and gave
to me 2 1964 motors. These also would make good conversions. The details of this are covered in your
Conversion Manual [available at The Online Catalog Page]. This man gave them to me because they were leftovers from a
pile of motors he bought in North Carolina, from which two very nice conversions were built. This
was a very nice gift, but it is also a good indication of how little the motors are really worth.
Not in a million years will a stranger pull up in front of your hangar and give you two O-200
cores (value $8,000) for nothing.
| | As explained in the Conversion Manual, forget looking at junkyards. The motors we want
are in the hands of Corvair fans nationwide. There are at least five national Corvair junkyards
owned by CORSA members that would gladly sell you an engine for half of what your local $500
ripoff artist wants. In fact, if he's shopping from Oregon, he is probably buying one for $250
from the Corvair Underground and doubling the price. If you really can't find one locally, you
should just contact them directly.
| | A number of people have had trouble finding an engine after looking for a week or two. But,
stop looking in junkyards and contact CORSA and you'll have much more success. If there is not
a local Chapter near you, go to the oldest auto parts store in your town (not a chain store) and
ask the senior counterman if he could put you in touch with a Corvair person. Trace one or two of
these leads, and you'll find plenty of motors.
| | Subj: Engine Selection, Zodiac Motor Mount
| | Date: 3/13/03
Just ordered your Conversion Manual today and I have a couple questions for you. I found a 1964 engine locally that has been
sitting in a dry shed for 30 years and apparently the rings must be stuck because you can't
turn it over. Does the condition matter
since it will be completely overhauled or should I look for a better one. Price is $125.00
including two older engines. I'm building a
Zodiac CH601 HD and had intended to use the Jabiru 3300 until a friend reminded me about the
Corvair. Reliability is the most
important issue to me and from what I read and hear this engine has it along with the
affordability.
| | Another question is about an engine mount for my Zodiac: Where do I get one or would
I have to make it myself?
Appreciate your help.
Thanks,
| | Dick Schmidt, Zodiac CH601 HD, Menasha, Wisc., rschmidt8@new.rr.com
| | Reply from WW:
| | To my understanding, all the 601 series aircraft are the same from the firewall forward.
I am looking into providing motor mounts and parts for these, the same way I already do for KRs
and Dragonflys, etc. When the time comes, I will undoubtedly have at least motor mounts available
for you. All of my other existing conversion parts are 100% applicable to 601s.
| | $125 is a little steep for a motor which will not turn over. If you can talk him down
to the $50-$75 range, it may be worth it. In many cases, I prefer to spend a little more money
on a better core because they tend to be a little less work when overhauling.
| | Subj: Case Studs
| | Date: 3/12/03
The top case studs are rusted off where the nuts are screwed over. What should I do about this?
| | Dean Mitchell, Bay Village, Ohio
| | Reply from WW:
| | The top case studs on motors were exposed to water and grime thrown off the rear wheels
of the cars. In states with salty roads, this tends to rust the ends of the studs. In extreme cases,
the studs need to be replaced. Frequently, it is easier to find a perfect case than to replace
the studs. Note that Larry's Corvairs in L.A. has a supply of excellent condition cases which they
will UPS to you. Call them for details. If just the tops of the studs are shot, you can consider
having a machine shop counter-bore the pads on the cylinder heads so that the nut will move
closer to the centerline and have full engagement after you re-assemble the motor.
| | Subj: Parts - Oil Pans
| | Date: 3/11/03
What is the status of your larger capacity oil pans? How far in advance do
we need to order?
Thanks,
| | John Krumrine, Zodiac 601XL, College Park, Penn., jqk4@psu.edu
| | Reply from WW:
| | The first order of oil pans sold out very quickly. The new order is arriving this week, and
I will have them on the shelf and in stock continuously from here on out. The popularity of
the Corvair conversion now justifies me stocking all of the parts in my catalog for immediate
shipment. Previously, there have been delays in shipment on some items, but this year, the
growing acceptance of the motor justifies an even greater investment on my part.
| | Subj: 1963 Corvair
| | Date: 3/10/03
Found a 1963 Corvair , the engine number is ti029zf. Is this an engine I can use? The car was an automatic transmission.
| | Cary Howard, Monticello, Fla.
| | Reply from WW:
| | Every week I hear from people who have gone out and purchased Corvair motors from $100
to $900 because they wanted to get started before buying the Conversion Manual. Your money
spent on a 1963 engine is unfortunately wasted. The Conversion Manual contains all the
acceptable letter codes and head numbers, plus instructions for selecting a good core motor.
I encourage anyone seriously contemplating the purchase of the motor to call if they have an
immediate question. Arming yourself with the information contained in my Corvair Conversion
Manual and studying it before throwing money at a core motor is the correct approach. Manuals
are available in the U.S. for $59, payable by check or money order in US Dollars to William Wynne, P.O. Box 290802, Port Orange, FL
32129-0802, or by credit card via PayPal at the Online Catalog Page
(add $15 for international S&H, including Canada).
| | Subj: Sun 'N Fun
| | Date: 3/9/03
I hope to make it to Sun-n-Fun in April . . . do you plan to be there? I have a few Corvair 164 engine parts to bring to ask
questions about.
Thanks for all your work in making an affordable flight engine possible.
| | Gary Kaplan, Mt. Juliet, Tenn., gary@garyglenwood.com
| | Reply from WW:
| | Good to hear from you. We will be building engines all week at Corvair College
during Sun 'N Fun, April 2-8, 2003, in Lakeland, Fla. Our full schedule is at the
News From The Corvair Authority page. This is exactly the kind of participation we're
looking for at this event. By all means, bring your Corvair parts (cleaned as outlined in
the Conversion Manual) and learn with the rest of the group.
| | Subj: Aerobatics
| | Date: 3/8/03
Having read some of R. S. Hoover's comments as linked from Ron Wanttaja's Web site
about building an inexpensive airplane I got quite interested in something like a Piet,
Corben or Fly Baby until I looked at the prices of (mostly runout) 4 cyl. Continentals
(65-100 hp) in a year-old issue of Trade-a-Plane (ouch - runout or not they are NOT
inexpensive!). Therefore I am quite fascinated about the idea of a Corvair engine for
inexpensive flying.
| | Now to my Subject; I do have an interest in Aerobatics. Would the Corvair be good for
"Sunday afternoon aerobatics," say in something like a Baby Lakes or Starduster SA-900?
(The literature Pete Bowers sent me on the Fly Baby even mentions its "excellent aerobatic
ability".)
| | Also, if I get infected by the speed bug, how would the Corvair do in, say, a 1 seat Midget
Mustang or RV-3 (both originally designed for 90-100hp Continentals despite the
subsequent horsepower races among homebuilders)? Sincerely,
| | Mark Boberg, Oak Harbor, Wash.
| | Reply from WW:
| | You're quite correct in your assesment that the Corvair is an inexpensive alternative
to the small Continentals. They are good engines, but the high price of parts for them means
that most Continentals have been run on shoestring budgets for many, many years, and thorough
overhauls on them are astronomically expensive.
| | The Corvair has obviously flown a number of the original airframes you mention, like the
Pietenpol and Corben Baby Ace. Numerous Corvair Conversion Manual owners are installing them
in Junior Aces and Fly Babys.
| | Everyone has a different definition of what "aerobatic" is. If you consult FAR Part 23,
Pete Bowers and Curtis Pitts, you're going to get very different answers. You need to develop
your own personal experience in aerobatics to judge your real interest. I have flown aerobatics
in jets and 450hp Stearmans, and personally hard core aerobatics with negative maneuvers are
not for me. I do feel that normal flight maneuvers and recovery from unusual attitudes
should be in every pilot's skill set; if you have proper training, your Corvair-powered airplane
can handle any of these maneuvers.
| | The RV-3 was never designed to fly on 90 or 100hp. You can check the Van's Web site; I
believe the minimum size listed is 150hp. On the other hand, Midget Mustangs do fly well on 85-100hp.
I'm currently looking into a 3,100cc/Midget Mustang installation at our own airport. It looks
like a very good match.
| | Subj: Engine Parts at Sun 'N Fun
| | Date: 3/7/03
I intend driving down to Sun 'N Fun this year. I was hoping that I could pick up some engine parts while I'm there.
Will you have available a 10/10 reground crank with safety shaft and studs? I can bring mine down with me as core exchange.
I'm also interested in the prop hub, the light weight oil pan, and a remanufactured dual ignition distributor.
Please let me know so that I can pack my distributor and crankshaft.
Thanks,
| | Neil Hulin, Zodiac 601XL, Cincinnati, Ohio, nhulin@hotmail.com
| | Reply from WW:
| | Good to hear from you. Let me take a moment to explain our crankshaft situation. We did a little less than 100
crankshafts last year on an exchange basis, but for various reasons only got about 40 good cores back. This temporarily
depleted my on-hand supply of cranks. Currently, I am offering the same regrind and prep to drop in status that I always have,
but it will be done to your own crank. The turnaround time, because the work is done at 2 different machine shops, is about 3
weeks. If you send us your crank now, we will be able to give it to you completely modified at Sun 'N Fun.
| | All the other parts you mention I will have on hand at Sun 'N Fun. You can bring your distributor core with you.
Distributor cores are not a problem, as virtually every one is rebuildable and I have approximately 200 cores on hand.
| | Looking forward to seeing you at Sun 'N Fun. Our schedule is at
flycorvair.com News from The Corvair Authority.
| | Subj: Turbo
| | Date: 3/6/03
My recent review of your Web site indicates that you have completed a great amount of R&D since
I last studied your development of the Corvair engine conversion for aircraft. I am very
interested
in your new motor mount and will be ready to order your prop hub and other components when I receive
the New Manual and determine what other newer parts or assemblies you have available.
| | You have listed the Christavia Mark I as one of the experimental aircraft that has been built with the
Corvair engine. Turbo normalization is also of interest to me for maintaining power at mountain altitudes.
| | Dick Schoen, Christavia Mark I, St. Paul, Minn.
| | Reply from WW:
| | I am very close to having a turboed direct drive motor that I believe will be the answer to the quest for more power
while retaining the simplicity of direct drive. I have the engine in my shop now, and I have gone to great lengths to
minimize any of the changes so the system can be of benefit to guys who already have built motors. I'll put the whole story in
the summer issue of The Corvair Flyer newsletter.
| | Thank you again for staying in touch. As you know, the work I've done has been a big part of my life, and while
it's very popular these days, I will always remember the guys who recognized my efforts and supported me early on.
| | Subj: Ring Gap
| | Date: 3/5/03
Today I started the reassemble of the engine with the able help of one of our
EAA Chapter members. He is a licensed engine mechanic. We have the crank and camshaft installed and it checked
well using the Plastigage. He requested I give
you a ring and see what you suggested for the piston ring end gap clearance.
He was looking at the Manual but thought that perhaps it should be a little
more than the listed specs as the engine is being used for an aircraft.
What are your thoughts on it?
He showed me how to correctly increase the gap by filling the ends of the
rings. Neat.
Thanks for you help.
| | Alex M. Sloan, Greenbriar, Ala., alexms1@bellsouth.net
| | Reply from WW:
| | You are quite correct in assuming that we like to run the ring end gap at the looser end of
the range. When a cylinder is bored for a forged piston, and the rings are slid down in the
bore to check, I like to see the ring gap closer to the upper end of the limit rather than the
lower end of the limit. One of the great advantages of air cooled engines is that they can be
run hot for several minutes. To do this without damaging the engine, the ring gaps cannot
close, otherwise the cylinder wall will get scraped badly. Comparatively, a liquid cooled
engine will boil off its coolant under the same circumstances.
I have found almost all new ring sets to check out at the upper end of the limit, but it is a
simple matter to insert the rings in the bore and check them with a feeler gauge to be sure.
| | Subj: Flybaby
| | Date: 3/4/03
Starting a Flybaby project and wonder if the
Corvair engine would be suitable?
| | tkorange@localnet.com
| | Reply from WW:
| | Yes, it's a good match. There are even a number of guys working on
two-seat
Flybaby/Corvair projects. Although most Flybabys were flown on 65hp Continentals, its
sturdy construction allows the use of more powerful Corvair motors. The Corvair's simple nature
complements Peter Bowers' design philosophy with the Flybaby.
| | Subj: Nice job
| | Date: 3/3/03
Hi,
just a quick note. A friend here in Casper, Wyoming, is finishing a Pietenpol
with Corvair power and has showed me your fine Manual, Corvair Flight
Engines for Experimental Aircraft. For the past 13 years, I have owned and driven Corvairs;
5 are running, one turbo. I'm a Mechanical Engineering teacher, with
some specialization more in diesel engines.
Thought I would say congratulations on such a fine book and Web site.
Your articles and book are so very well done and technically correct. You
really have a thorough understanding of the subject and it is a treat to see
things done so well. I wish you the best!
| | Ardell Knudson, aknudson@caspercollege.edu
| | Reply from WW:
| | Thank you for the very nice compliments. Coming from someone who has both a
background in the mechanical world and education, I take it as a real compliment. The
work in the 2002 series Conversion Manual is not only the result of years of work on
Corvair engines, but also the accumulation of a lifelong interest in things mechanical.
Along the way I had many teachers, and I'm sure I never thanked them all properly, but a lot
of the credit belongs to them. I'm sure many of your students feel the same way about you.
| | Subj: Wag Aero Sport Trainer
| | Date: 3/2/03
William, I'm looking to build the Wag-Aero J-3 Cub with the shortened wing
option (also the L-4 Observer conversion). Anyway, what do you think of
the Corvair in this plane? Also, why not use the 140hp engine? I own a '63
110 Monza convertible and LOVE the engine. Thanks for your time.
| | Rick Davitt, rickdavitt@shrinkpackaging.com
| | Reply from WW:
| | The Corvair is a good engine for either the standard J-3 or the shorter wing versions.
A standard J-3's engine is of course only 65hp, and I have seen clipped wings fly well on motors
as small as a C-75. Although both of these engines make their rated power at low rpm, the
difference in thrust per horsepower is not nearly what most armchair theorists would have you
believe. The Continentals turned 72" diameter props. The Corvair can easily turn a 68" or 70"
prop, and the additional horsepower of the Corvair makes for an engine installation with
substantially more thrust than the small Continentals. If anybody tells you differently, simply
ask them which Corvair motor they tested. I have found that the people who blindly repeat
theory have never tested anything.
| | The whole story on 140s is covered in the Conversion Manual, available by check or money
order for $59USD (add $15 for overseas S&H) payable to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802. You can pay by credit card via PayPal at
the Online Catalog. But in a nutshell, the 95 or 110 motor converted
according to my Manual actually makes more power
below 3200rpm. Since all of the operation of a direct drive motor in an airframe like an L-4
is below this rpm, it is the optimum motor. Additionally, the 140 is the only motor in the
Corvair line known to drop valve seats. For these reasons, I recommend the 95 and the 110.
| | Subj: Corvair College
| | Date: 3/1/03
I'm going to try to make it to your place prior to Sun 'N Fun, and also
to SNF.
What will I need besides long block?
Do you have any TRW pistons?
Will you have any prop hubs available?
I'm planning on using front mounted starter and alternator accessories.
I already have Corvair fuel pump and 12 plate oil cooler.
| | Greg Jannakos, Zenair 601, Ga., gpjann@juno.com
| | Reply from WW:
| | The next step on your engine would be the connecting rods, pistons, rings and cylinders.
Your Conversion Manual details exactly which parts these are, and what needs to be done to them.
I generally do not keep a big stock of pistons and cylinders and similar items on the shelf
because they are readily available from the sources listed in the Conversion Manual, and I avoid
being the middleman on standard parts. Once you have these items on hand, the next step would
be to bolt on the cylinder heads, which of course need a valve job before they're installed.
Cleaning and painting the pushrod tubes and the rest of the valve train components before hand makes the
assembly go smoother. If we have to take time to do these in my shop, it reduces what can be
accomplished in a weekend. My pre Sun 'N Fun Open House is the weekend of March 15-16. All of
the conversion parts that I sell, like prop hubs, aluminum oil pans, hybrid studs, etc., will
be available.
| | Our Sun 'N Fun schedule is posted at News from the Corvair Authority.
All Conversion Manual owners are invited to build up their engines for free at Corvair College, just as
we've done at the past three Colleges. Everyone is always welcome to watch and learn. The only difference is that this
year's College is at Sun 'N Fun rather than at my hangar, and they charge
admission. Their Web site is www.sun-n-fun.org. Looking forward to seeing you in Lakeland.
| | Subj: High compression Corvair
| | Date: 2/28/03
I just ordered your book on Corvair conversion, but I have a question I am
sure is not covered in it. I will be building a 194 cid engine and I would
like to use as much as 12:1 compression on it. I will not do this to gain
horsepower, but rather to retain the 75% hp to a higher altitude. I would
also want the additional compression down the line when I convert it to use
alcohol fuel. My question to you is, would this be possible without hurting
the reliability very much? If you do not know the answer, could you put me
in touch with someone that can answer it?
By the way, I will be putting it in the lightest weight BD-4 ever built.
Thank you for your time.
| | Dale Neddeau, BD-4, dneddeau@hotmail.com
| | Reply from WW:
| | Your question is certainly not run of the mill, but it is far from the most unusual one
I've ever received. I do not believe that raising the compression ratio will retain as much
power as you think at altitude. The motor would also detonate if the slightest mistake was made
about opening the throttle too far at low altitude. A naturally aspirated motor loses power at
altitude because the same volume of air has fewer molecules in it and because the effective
cylinder pressure is dropping. Your proposal would counter the second factor, but not address
the first. I would honestly suggest considering a turbo instead. I am continuing my work on
direct drive 2,700cc turbos, and I think it would be a much more promising altitude engine.
| | As for running the motor on alcohol, most of the high end Corvair powered sand
dragsters run on alcohol. Guys like Bob Sutcliffe, whose number is in the Manual, have a fair
amount of experience with this. My personal experience with alcohol is limited to motorcycle
drag racing. The horsepower improvement potential is about 15% on a naturally aspirated engine.
Against this, peak power air/fuel mixture is only 6:1, giving the engine a ravenous appetite
for fuel. And the main problem: it's horribly corrosive and will attack almost everything in
a standard fuel system, including the tank, the lines, the inside of the engine.
| | A 2,700cc turbo Corvair motor would probably be a much better bet for your ultra light
weight BD-4. (Note: BD-4s are not normally within the Corvair's hp range.)
| | Subj: TITAN AIRCRAFT'S NEW T-51 3/4 SCALE ALL-METAL MUSTANG
| | Date: 2/27/03
Hi William, always enjoy your articles on what's going on in the
aviation/Corvair engine world! I shared a few e-mails with you last year
regarding the Corvair engine's ignition system, and about the old '66 Dodge
pickup and engine with 86,000 original miles I found and bought. I have
overhauled several engines myself over the years and served as a crew
chief/mechanic on Hueys in Vietnam and Germany. Always enjoy engine work
and do most engine and other repairs on vehicles I own.
| | Now I am truly interested in buying a kit airplane to use a Corvair engine
in. Last year I was interested in the Loehle wood and fabric P-51 Mustang
replica, but when I mentioned using the Corvair engine with their P-5151
model, Sandy Loehle told me they had not heard of it, so never considered
it. When I told her the weight of the engine, she thought that the weight
may be too much for their design. They had no plans for attempting any
tests, but now with subject Titan aircraft coming out, they may become more
"adaptable" to compete.
| | Do you have any information on subject aircraft's potential for using the
Corvair engine? The Titan T-51 is gorgeous looking in the pics I have seen,
and since the P-51 was always my fav WWII airplane, I would be thrilled to
build and fly one! Here is the Web site for the Titan:
http://www.titanaircraft.com
| | Thanks for any help you can provide, although it appears you have very
limited time, so I feel fortunate if I hear from you.
Sincerely,
| | Wendell McGinness, Titan T-51, Gig Harbor, Wash.
| | Reply from WW:
| | We saw this plane in person at its Sun 'N Fun debut last year. It drew a huge crowd.
The pictures don't do it justice. It's very nice. I believe the intended engine for it is a
912S or a 914. They are working very hard to keep a decent useful load and stay under 1,232
pounds for the new Sport Pilot rule. If you're really interested in this plane, you might want
to call them and ask if it could be flown on an O-200. If the answer is yes, it's a good possibility
the plane could be Corvair powered.
| | I have recently been contacted by a company in Australia building a 1.6:1 gearbox for
the Corvair. More information is due in the coming weeks, but this aircraft might use such a
setup to turn a more scale prop. I almost never suggest using a gearbox, and this one is as
yet unproven. But, I'll keep an eye on it for everybody.
| | Subj: Corvair in Ercoupe?
| | Date: 2/26/03
Would the Corvair be a good engine for the 415C Ercoupe?
| | jleonard@cox-internet.com
| | Reply from WW:
| | Most Ercoupes were powered by 75 and 85hp Continentals. The Corvair, at 100hp, could
certainly power the aircraft. All of the difficulty of mating the two would be in getting
approval from your regional FAA office, and operating the aircraft under the restrictions they
might impose. If you're considering such a project, contact your local FSDO on the approval
procedure and flight limitations.
| | Subj: Dual ignition
| | Date: 2/25/03
Do you have a dual ignition set up for the Corvair and possibly dual plugs? I have had to put
a plane down in the water due to ignition
problems, so I hope you understand the reason for my question. Thank you.
| | Paul Mallard, papaquack@aol.com
| | Reply from WW:
| | The Conversion Manual details all the developmental work and experience I have with dual
ignition. My current dual ignition setup has two of all the heat sensitive components: points,
coils, etc. Yet it retains the simplicity of single plugs. It is flight proven with hundreds of
hours of service. I sell these distributors, complete, including Priority Insured shipping, for
$219 at the Online Catalog, or you can send a check or money order payable to William
Wynne, P.O. Box 290802, Port Orange, FL 32129-0802.
| | Subj: Change to Manual info
| | Date: 2/24/03
I think the phone company changed the area code on you...Page 21 shows CORSA phone number as 709-
and it is now 630....you might want to change that...
| | Bob, rwbtoy@internetcds.com
| | Reply from WW:
| | Thanks for the tip. For everyone else reading this, CORSA is the Corvair Society of
America. It is the national group for owners' of Corvairs. It is a large group, with state and
local Chapters.
| | Subj: C-150s and Corvairs
| | Date: 2/23/03
I'm looking at a couple of Cessna 150 airframes, less engines. They can be had for next to nothing. Is this a candidate for a
Corvair engine, and if so am I opening a can of worms?
Looking forward to hearing from you.
| | Ron Jones, Shelby Twp., MI
| | Reply from WW:
| | A Corvair would certainly power an early model Cessna 150 nicely. The earlier model
150, the better; they were lighter and had lower drag.
Here's the catch: You'll have to receive special permission from the FAA after filing proper documentation, and there will be restrictions on
how and where you can operate the aircraft. The documentation may have to include a report from a licensed engineer on such items as
engine mount design, etc. It can be done, but I highly suggest you contact your regional FAA office and learn all the details before you
actually acquire the aircraft.
| | Subj: How to clean the block?
| | Date: 2/22/03
What is the best procedure to clean the block? If sandblasting, what media
do you use? If some cleaning fluid, what is used? Or other???
| | Thanks, Greg, g_geer@blomand.net
| | Reply from WW:
| | The 2002 Conversion Manual contains an extensive section on cleaning techniques. In short, never sandblast anything on the motor.
This restriction includes glass beading. The only acceptable blast media would be Walnut shells or plastic. Glass or sand will upraise and
destroy the fit under the bearing shells, in the lifter bores and on the mating surfaces. Gunk engine cleaner, pressure washing and carb
cleaner and brushes are a much better way to clean the aluminum parts on your Corvair motor.
| | Subj: Just Starting
| | Date: 2/21/03
Hi to you William. My name is Charles Storey and I'm just starting to consider building because the cost of buying aircraft has
gone into orbit and just doesn`t seem to fit my wallet. I've been talking to people about building and the subject of engines came up
and I was told that your Corvair engine is going to be the recommended engine for this. Now I've said all that to say this: I'm no
Mechanic. I'm good at carpentry, and just about all home repairs, and can change a plug or two. I can take one part off and put
another one on, so is this going to be too big of a job for someone like me to tackle, or should I just hope to find one already
done. Stuff like this really confuses me. Any thoughts or suggestions will be most helpful, because as you know, money doesn't
grow on trees. Thanks for your time. Hope you can help.
| | Charlie Storey, RAMBLER444@aol.com
| | Reply from WW:
| | Many years ago when I started my work with Corvair motors, it was with the sole intention of helping out guys just like you.
A big part of the reason I chose the simplicity of direct drive, air cooled and simple systems is because it's the only practical engine to
teach people to build for themselves. Complex engines would be beyond the scope of safely teaching first-timers to build for themselves.
By and large, a Corvair motor, as converted, requires no machine work for you to do. It requires only careful assembly and light fabrication.
When a first time builder expresses the same concerns you have, I'm never worried. In my experience, first time guys exercise more care and
tend to build by the book rather than with a been there, done that mentality. Converting the Corvair motor is much easier than building the
simplest airframe.
| | Occasionally people ask about buying a motor that's "rebuilt." I sincerely recommend against this. In the past years, with my help,
dozens and dozens of Corvair motors have been rebuilt. The owners are justifiably proud and I cannot think of a single one which is for sale.
Occasionally, stories surface of engines for sale, but I know from our records that we've never met the seller, and he doesn't own a copy of
the Conversion Manual, so I largely suspect it's just an overpriced car engine. You're always much better off to buy a good core motor and
rebuild it yourself. You'll know a lot more about the motor when it's done, you'll have the pride of having created it, and you'll be putting your
trust where it belongs, in your own craftsmanship.
| | Subj: Corvair College #4
| | Date: 2/20/03
I had a request for more info on the upcomimg Corvair
College. What is the cost & exact dates/time (since Sun 'N Fun is running
Wensday through Tuesday).
| | Michael Amick, mkamick@edge.net
| | Reply from WW:
| | Our Sun 'N Fun schedule is posted at News from the Corvair Authority.
All Conversion Manual owners are invited to build up their engines for free at Corvair College, just as
we've done at the past three Colleges. Everyone is always welcome to watch and learn. The only difference is that this
year's College is at Sun 'N Fun rather than at my hangar, and they charge
admission. Their Web site is www.sun-n-fun.org. Looking forward to seeing you in Lakeland.
| | Subj: Corvair for Australian Piet
| | Date: 2/19/03
G'day, have just started on a Piet long fuse, (plans from Andrew P) and
would like to use a Corvair. As you are probaly aware they are a bit thin
on the ground over here so would like to know whether you have looked at
shipping a suitable core and some of your other mods to Oz. I have noticed
on one of the UK sites that you have sent some there. If you can let me know
if it can be done and an estimate of shipping costs I will start talking to
customs at this end to see where I stand.
| | Regards, Arthur Johnson, Townsville, Australia, aejonhson@email.com
| | Reply from WW:
| | It is true I've shipped aircraft motors and cores to Brisbane and Birmingham. Incidentally, I've shipped Manuals to such far flung
places as St. Helena, Sai Pan and South Africa. The last time we sent a motor to Australia, the shipping was about $500 by air freight. Contact
me when you're ready.
| | Subj: CORSA motor
| | Date: 2/18/03
Thanks for returning my e-mail, and the info about the prop. I was a little
alarmed to hear about the potential destructive flaws with this motor. I
hope you can enlighten me some more to what they might be.
The motor I have is a genuine Corsa motor. Serial number TI 216 RB. Mileage
- 63,000. It was overhauled according to the 1965 Corvair shop manual. I
purchased it from an ex- helicopter inspector in England, now in Adelaide,
Australia, who originally rebuilt it in England and brought it out to
Australia some years ago. It is the 4 carburetor engine, which was
converted to a single Aircraft Carby underneath, which I have now changed to
a Dual side draught Webber, one half of the 45mm carby feeding each side of
3 cylinders, also underneath (I will not be flying over 5000 feet). It has
not been run since re-built.
However following is what has been done to the motor internals:-
Crank crack tested using X-Ray. Crank dimensionally checked. Cylinder head
cooling fins cleared of casting flash. Airways opened up. Cast iron valve
guides replaced with aluminium bronze guides. Valve seats re-cut and valves
re-ground and assembled with new springs. GM cast alloy pistons replaced
with TRW forged alloy pistons. Double capacity oil pump fitted. Camshaft
replaced with Otto TB-10 shaft to improve lower RPM performance. New
hydraulic tappets. Sump replaced with cast aluminium ribbed cover. GM main &
big end bearings replaced with TRW CL-77 High performance shell bearings.
All oil seals replaced and push rod "O" rings replaced with Viton rubber
seals. Engine re-assembled with shake proof bolts and hardened flange
cylinder hold down nuts. Crankshaft, Prop Hub, Harmonic Balancer and starter
ring dynamically balanced. Pistons and con rods Statically balanced.
Also Thrust Bearing:- Based on American experience (Bernie Pietenpol), It is
of the later type with a thrust face on both halves. All parts replaced are
either TRW or OTTO parts.
Is this sufficient not to have to strip the motor down again, or are the
potential problems not covered by what has been done.
Please let me know what is needed to be done, and what your Manual is now
worth. Also do you accept VISA Card.
Hoping to hear from you again.
| | Regards, Roger Foster, randgfoster@hotmail.com
| | Reply from WW:
| | Thank you for your detailed records. It sounds like the engine had a first class rebuild. The only item on the engine that I would
change would be the cylinder heads. Although this sounds extensive, it's not. Virtually all the other parts on the motor will bolt right to them.
The only difference is that the 110s require a slightly different rocker arm. Your cylinder heads, as they are, are worth about $400USD. You
could easily find someone with whom to exchange them for a fully rebuilt set of 110s or 95 heads. The 140 heads do not make power at
direct drive rpms. This is covered in the Manual, which costs $59, plus $15 for overseas S&H. You can pay by credit card via PayPal at
the Online Catalog.
Although several people are interested in Webers, the best setup is yet to be determined with this carb. I strongly suggest running both barrels
into a common plenum. A single barrel feeding a long intake track on the Corvair can send a resonant pulse down the tube. This is eliminated
by feeding a common plenum. It's not a problem on the car because the intake is short.
| | Subj: Excavating an Engine
| | Date: 2/17/03
Hi, Thanks for the manual and video tape at San Geronimo, TX.
I have the 1965 Corvair shop manual and after reading the engine and
transaxel removal instructions and special tools needed, I am still
wondering what to do at the junk yard when I go to pull the engine
myself. What process do you recommend for the "Pull the engine from a
car sunken into 20 years of dirt"?
O.K. Then how much would the shipping be on one of your engines to San
Antonio?
| | Richard Elder, San Antonio, Texas, relder@flash.net
| | Reply from WW:
| | We had a great time in San Antonio. The best way to remove the motor from a late model car is to jack up the back end of the car
till the bumper is 30" high or so. Remove the bolts around the bell housing, with the exception of the bottom two, and disconnect the motor
from the rest of chassis, wiring, fuel line, etc. With the carburetors removed, you can lower the car down, disconnect the rear motor mount
by the harmonic balancer, and take the bottom two bolts out. When you jack the body up this time, the motor will sag down and it can be
slid away from the transaxel and out from under the car. If the car has an automatic transmission, you'll have to disconnect the three bolts from
the torque converter to free it from the flex plate. Richard Finch's How to Keep Your Corvair Alive has step by step instructions on his
method of engine removal.
| | I have traditionally sold dozens of engines inspected and guaranteed to be rebuildable for $299. This served me well to jumpstart the
re-emergence of the Corvair motor, and got a lot of people going. Today, the popularity of the motor leaves me little time for tasks that guys
can easily accomplish in the field, such as acquiring a core motor. The popularity of the motor dictates that I spend more time doing things
like driving to Texas to teach you and other builders. I heartily encourage you to get your core motor locally. Not only will it be cheaper than
me having to ship it to you, your tracking it down and liberating it from a junkyard will provide a much more dramatic beginning to the story
of how you built your own airplane motor.
| | Subj: Carb Ice
| | Date: 2/16/03
Does the Conversion Manual deal with adding fuel injection? I'm paranoid when it comes to carb ice.
| | Ron Mills, Burbank, Calif., MILLS42@aol.com
| | Reply from WW:
| | The Conversion Manual covers the issues surrounding fuel injection, and my opinion that carburetors are a much better idea
for amateur aircraft builders. Plenty of airplanes have automatic carburetor heat; an Ercoupe is a good example. There is no need to be
paranoid about carb ice. If you read the Web site closely, on the Carb Ice Page you'll learn that fuel injected engines are not immune to carburetor ice.
The complexity of installation and high pressure fuel
pumps associated with fuel injection are things of which to be leery. People have flown millions of hours on carburetors, even without
automatic carb heat. This has been done safely. Amateur fuel injection does not have a safety record to match this.
| | Subj: Looking for Engines in Indiana
| | Date: 2/15/03
William, I just ordered your Conversion Manual a couple days ago using your PayPal method [Online Catalog].
My wife told me to just order it by mail, but I want it yesterday.I wanted to know if you know of any places in the
Indiana area that may have an engine or two laying around? If they are what I need to get the job done, I will travel to Illinois or
Ohio. Thanks in advance and I'm looking forward to getting your book. I'm hoping to put it in a
KR2S some day. Thanks again.
| Bob Glidden, KR2S, Martinsville, Ind., glidden@ccrtc.com
| Reply from WW:
| | Thank you for your order. I'll research my records and also invite anyone who reads your request here to contact you directly with any leads in your area.
| | Subj: Engine break-in runs
| | Date: 2/14/03
Hi William.
I have two hours of run time so far, 4 half hour
sessions. On the last run, I did 30 seconds of WOT at
three different pitch settings. The Ivo Prop range is
30 to 90. With it set right in the middle (approx 60)
the rpm was 2300. I turned the prop back 1 turn
(approx 54), I got 2400 rpm. And then I turned it back
another turn (approx 48) and got 2500 rpms. Is the
Ivoprop so far off that I don't know what pitch it is
at, or does that static rpm sound right for a 60 inch
prop. I have the carb set pretty decent. I haven't put
a timing light on it yet. How many hours should I run
it before I do extended WOT sessions. And how long
should I do WOT at a time. And what static rpms should
I try to achieve with a 54 inch wood prop.
| | Del Magsam, "Outlaw Sonex," New Richmond, Wisc., farmerdel@rocketmail.com
| | Reply from WW:
| | Good to hear from you. First, before anything else, verify your maximum timing advance. For ground runs and break in, use 30
degrees of total ignition advance as an upper limit. You'd like all this advance to be in before 2,400 or 2,500rpm.
| | The propeller pitch sounds like it's in the right neighborhood. As you know, I'm no fan of Ivoprops. Keep a very close eye on the
hub for any signs of separation or rough running behavior. The Ivoprop I sold to Bob Bean for his Lycoming-powered Tailwind disintegrated
in the 1999 Sun 100 Air Race. If you choose to fly this prop, please pay very close attention to it.
| | You want your static rpm to be approximately 3/4 or more of your planned WOT level flight rpm. I would not use less than
2,500rpm static in a plane like a Pietenpol, and with a smaller diameter prop in the 54-58" range, I'd shoot for a number like 2,750 or better.
Before any runs at all, make sure that your engine is completely baffled, and you run it with the cowling on. Before I fly a motor, I like to see a
30-45 second run with the airplane blocked up to its maximum angle it will see on climb out to verify that fuel flow at full power is adequate.
Keep an eye on the oil pressure gauge also. With all of your baffling and cowling in place, and the engine properly broken in and warmed up, you can run the
engine at full throttle as long as the cylinder head temperature is in the green arc. Before the engine is fully broken in, I would limit WOT to about
2 minutes.
| | Subj: Crankshaft dampeners
| | Date: 2/13/03
Are crankshaft dampeners used on the Covair engine? What brand do you
use and do you sell them? Thanks,
| Howard, howash@juno.com
| Reply from WW:
| | Almost all 164cid Corvair motors left the factory with harmonic balancers. The standard harmonic balancer will fit any model engine I
recommend for flight conversion. Most of these balancers have damage to the rubber after 35 years. Dale Manufacturing has rebuilt
thousands of balancers, replacing the rubber with cast urethane. These balancers are available from the suppliers listed in my Conversion Manual.
They are not expensive, and I have used one on every motor I have ever built.
| | Subj: Reverse rotation 'Vair
| | Date: 2/12/03
In your Conversion Manual you mention that you are working on a reverse
rotation Corvair engine. I'm currently kicking around the idea of a twin
BearHawk and was wondering what luck you've been having and how far along in
the process you are.
| | Dr. Andrew Rekow, BearHawk, Waterloo, Iowa
| | Reply from WW:
| | I am building the reverse rotation motor currently in the shop. I expect it to be done just after Sun 'N Fun, and I'll have a complete
list of the details that go into it in the Spring issue of The Corvair Flyer newsletter.
| | Subj: Christavia MK IV
| | Date: 2/11/03
Would the 4 place Christavia MK IV be severely
underpowered with the Corvair motor? Thanks for any
info.
| | Joe, antjuju58@yahoo.com
| | Reply from WW:
| | I am not familiar with the Christavia MK IV performance details. I did note that the Christavia 2-seater was originally advertised to
fly on 65hp, but the general consensus of builders was that 90 or 100hp was a practical minimum. This leads me to believe that the
four-seater would require more power than the Corvair could economically deliver.
| | Subj: Just started
| | Date: 2/10/03
I just started tearing down my engine, and I have a few questions. I
bought the engine from the Corvair Ranch in Gettysburg. It is out of a '66
and has the RD Towanda suffix.
| | When I removed the first head, I saw that the one piston had a hole burnt
through it. I'm planning on replacing all the pistons and rods, so my
question is, would this type of damage have created any other problems with this
engine that I should be looking for? The engine turned over, but could it
have bent the crank?
Thanks,
| | John A. Krumrine, Zodiac 601XL, State College, Penn., jqk4@psu.edu
| | Reply from WW:
| | It is not likely that the motor was damaged at all by having the weak, stock, cast
piston let go. I would be particularly careful when cleaning out the oil cooler and the oil
galleries, as this metal went somewhere in the motor. The people who rebuild your connecting
rods will be able to check the straightness of the rods. A standard rebuild as I recommend in
the Conversion Manual (available by money order
or personal check for $59USD plus $15USD for S&H for those outside the U.S. payable to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802, or by credit card via PayPal at the Product Catalog Page)
will work fine on this motor.
| | Subj: Sonic Detectors
| | Date: 2/9/03
On Page 17 of your 2002 Manual you refer to a "stand-alone sonic detector"
in a back issue of Contact! magazine. Doing word searches on
their Web site on their back issue summaries turned up nothing using the
word "sonic" or the word "detector." However, using the work "knock" turned
up:
| | Issue 28: "Steve Parkman develops a stand alone engine knock sensor.
Complete DIY plans are included."
| | Q1. Is that the issue to which you were referring?
| | Q2. Also, what oil temp min and max limits would you suggest for Take-off,
Climb and Cruise?
Thanks,
| | G. Andris Vaskis, Manual #5236, vaskis@gte.net
| | Reply from WW:
| | Yes, that is the Contact! issue to which I'm referring. Pat Panzera,
panzera@experimental-aviation.com, who is
the current editor of Contact!, is a Corvair engine builder. Also, Steve Makish,
Boca Raton, Fla., is flying his Corvair-powered KR2 with an MSD knock detector. These are
available from hot rod shops.
| | I would consider 160F to be the lowest oil temp I would fly at; 180F would be a better
idea. Ideally the motor would operate above 212F to boil off any condensation or entrained
water in the crank case. New motors will occassionally hit 260F on a climb. After a few hours
of operation, you'll notice the oil temperature will drop 20-30 degrees due to reduced internal
friction in the motor. We run fully broken in motors on synthetic oil. I don't have specific
information on what is too high for synthetic oil, but I strongly suspect you could run it
30-40 degrees hotter than non-synthetic oil without damage.
| | Subj: John Deere Alternator
| | Date: 2/8/03
William, we have the new John Deere Alternator that you recommend in the Manual but have run
into a problem in mounting
it so it can be driven. Our question is, "If we drive it from the original balancer pulley it
will be turning in excess of 8,000
RPM,-- Will it stay together or will it tend to throw the segments out of the armature?"
We have clearance to add a smaller pulley to the face of the balancer but the mounting would
be more difficult so we would like
to drive from the balancer pulley. Please advise us as to what you recommend?
We are anxious to get this engine running so we can be ready for the fly in season.
Respectfully,
| | Ray and Rich Hill, Pietenpol, raydot@pcpartner.net
| | Reply from WW:
| | We have an awful lot of flight time driving the John Deere alternator from the stock
pulley, so I can assure you that it works, even though the rpm is high. The design of the unit
is such that only the magnets are rotating, and they are bonded to the inside of the cup-shaped
outer housing. Thus, centrifugal force holds them in place instead of straining the bonds. I
have momentarily turned one of these 16,000rpm by accident, and it did the unit no harm.
Reducing the pulley diameter is technically a good idea, but not necessary.
| | Subj: CH701
| | Date: 2/7/03
Will this engine work in a ch701 or is it too heavy? Thanks,
| | Miles, M150@aol.com
| | Reply from WW:
| | The Heintz family has told me directly that they do not want engines which weigh 200lbs.
or more in the 701. Despite the fact that their 701 brochures have pictures of engines like O-200s and
EA-81s, which weigh as much or more than a Corvair, they do not encourage installations like this.
A number of people who liked the 701, but wanted to use a Corvair, are now working on an aircraft
called a Pegzair from Canada. You can find out more about it in the EAA Aerocrafter catalog.
| | Subj: Forged Pistons
| | Date: 2/6/03
Mr. Wynne, Turns out Larry @ Larry's Corvair is recommending
boring out a '60 cylinder (not a '61 cylinder) to the 110 HP standard piston size. Then fasten it to a late model case and crank.
Top it with a '61 102 HP head (9:0 compression). Run standard size 110 forged pistons on a late model crank. It seems to
me that the boring process increases the volume of air being compressed - therefore, the CR must increase. Larry says no,
it doesn't. He insists that he's done this same operation for other aircraft builders. Can you help here? Also, do you
know if the '60 heads are heavier? Too heavy? Would appreciate any help you might care to give.
Thanks.
| | John, josandt@netzero.net
| | Reply from WW:
| | The operation as Larry described will work. The Corvair's advertised compression ratios are slightly optimistic. I haven't done the
calculation, but would suspect Larry is correct that the compression ratio is just a little over 9:1. '60 cylinders are slightly heavier than others,
but it's not much, maybe 2 pounds for the whole motor. The '61 heads should weigh just about the same.
| | Subj: I'm inspired now... hand me the wrench!
| | Date: 2/5/03
Thanks again for visiting our EAA meeting last night. It was definitely an exciting presentation and I am now pretty certain that
I will be embarking on a Corvair project this year... as soon as I get through the wedding I'll be getting your Manual and looking for an
engine core. (Maybe sooner if I can manage it!) I've realized that working on these engines is not nearly as scary as I had come to
believe previously. Looking at a typical modern car engine can be a bit imposing, but when you see the Corvair motor, you realize
that there really isn't that much to it. The thought of building an engine for a homebuilt has gone from being something that I was
going to leave to the experts into something that I both can and want to achieve myself, with the expert's friendly guidance and the
benefit of experience gained by those who have done it before me. Like you said, learning by doing instead of merely buying the
engine will help me gain knowledge and skills that will make me a better airplane builder and a safer pilot. As far as I can tell, it
would be hard to beat a Corvair for a good engine to learn these skills on... it's not all that complicated! You guys have a great
attitude that truly reflects the spirit of sport aviation that has attracted me to experimental aircraft for longer than I can remember.
I will definitely see you guys at Sun 'N Fun to learn even more.
| | Will forward a copy of the EAA meeting report when I'm done. Thanks again to you, Gus, Arnold, and Dave... everyone
enjoyed it a lot and were genuinely excited about Corvairs!
| | Mike Whaley, merlin@ov-10bronco.net, MerlinFAC@cfl.rr.com, Webmaster, OV-10 Bronco Association
| | Reply from WW:
| | Thank you for your kind words. We got your newsletter and it looked great. We look forward to seeing you again at Sun 'N Fun.
| | Subj: Corvair engine for Zodiac XL
| | Date: 2/4/03
Just thought I'd drop you a quick note to say that I'm building a Zenith
Zodiac 601XL, and I've been following with some interest the recent
indications that you may be working with a Zenith builder to create a FWF package for
the XL. If there is any truth to that, I just wanted to add myself to the
list of interested builders. The Corvair conversion seems to be just the
ticket for an economical powerplant for my XL (and yes, I already have a
copy of your Manual!).
Any word on when you might realistically have a FWF package available, if
that is still your intention? Thanks.
| | Mike Fortunato, Zodiac 601XL, mike@city-commercial.com
| | Reply from WW:
| | I am still working toward that package. Please note that I'm working on it independently,
not with the factory. The Heintz family remains neutral on alternative engine installations
which they have not personally tested. While they have been fairly supportive, the development
of the combination is being done solely by me here. I'm very busy prepping for Corvair College
#4 and Sun 'N Fun, but I suspect I could have this done by Oshkosh.
| | Subj: Bell Housing
| | Date: 2/3/03
William,
Thank you for taking time out of your schedule to reply.
Actually after I sent the e-mail to you, a fellow called who had a Corvair about 25 minutes from the house. The motor turned over so I offered
him $100 for it. He accepted, then ended up giving me the whole car. It was the RF designation and had matching heads of the 110
non smog variety. Haven't taken it apart, but everything looks ok.
Since I made a deal with the guy in Little Rock, I feel obligated and will make the drive. I shouldn't have been so hasty, but he has my word.
Lastly, will the bell housing for the standard transmission work, or will I have to obtain one from an automatic?
Best Regards,
| | Ed Jones, Xocouple2001@aol.com
| | Reply from WW:
| | We're answering this on the laptop while driving down the road. Gus is in the back seat and says thanks again for dinner in
San Antonio. On the bell housings, either one can be used. They're completely interchangable. Keep in touch. We'll see you soon.
| | Subj: Engine Choices
| | Date: 2/2/03
When you
have a wide choice of Corvair engines, is there a particular one you would
prefer? Also, they will sell me an untested engine for $350 and a running
engine for $450. Is there any advantage to buying the running engine if I
plan to rebuild it anyway?
| | One final question. I have a Subaru Legacy wagon and hope to pick up the
engine in my car. I know about all the measurements, but do you know of
anyone who has ever tried to transport a Corvair engine in this size vehicle?
| | Thanks for your help. I 'm hoping I'll be able to get to Sun 'N Fun and
meet you personally.
| | John A. Krumrine, Zodiac 601XL, State College, Penn., jqk4@psu.edu
| | Reply from WW:
| | The Corvair, stripped of the outer sheet metal, will certainly fit in anything pretending to be a station wagon. In looking for a motor,
generally we're looking for a 1965-69 95hp or 110hp. All the letter codes and serial numbers are contained in great detail in the Conversion
Manual, available by money order
or personal check for $59USD (add $15 for S&H outside the U.S.) payable to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802, or by credit card via PayPal at the Online Catalog. Please note that either motor, the 95 or 110, will produce the same 100hp when converted for aircraft use. It does not matter which
one you start with. For $450, the motor would have to run pretty darn well. This includes idling well and not smoking. Running motors have
the advantage that they are almost always rebuildable at a lower cost. The price these people ask demands the motor be in very good
condition.
| | Subj: Corvair Prop
| | Date: 2/1/03
I have obtained a Corvair Corsa motor which has already been modified for
Aircraft use, with an output of approximately 100 hp, but I am currently
remodeling it to suit my requirements. It will be going on a cantilever low
winged single seat aircraft. What I would like to know is, what type of
ground adjustable propeller do you recommend, and what diameter. The engine
will have a maximum rpm of 3300 revs. I need a ground adjustable prop, as at
this stage, I do not know what pitch I will need and I will have to
experiment.
Can you assist me please.
Hoping to hear from you.
| | Roger Foster, randgfoster@hotmail.com
| | Reply from WW:
| | I will be glad to help you in any way I can to ensure you safely operate your motor. Anything I comment on
comes from first hand testing. The Internet being what it is, a lot of advice is tossed around by people who have never
tested anything.
| | Corsa refers to a 1965-66 140 or 180hp Corvair motor. I have flown both of these motors in the direct drive
form and they perform poorly. Additionally, they each have potentially destructive flaws which are not shared by the vast
majority of non-Corsa Corvair motors. A lot of people use the term Corsa loosely, so perhaps you do not have one of these
engines, but it is a serious matter, so I ask.
| | Before you fly a motor, you need to know what is inside. Despite the fact that I have sold thousands of conversion manuals, many people do not follow recommendations I make. It is a free world and this is OK, but many of these motor are later sold as "converted according to WW's manual" when they are not really close. A lot of this is small but crucial deviations which can be corrected without too much work. It is well worth checking into what you have.
As for props, there is only one adjustable one which is flight proven on the Corvair, the Warp
Drive. I would start with a 66" two blade without tapered tips. This can be trimmed if it proves to need it. We have sold a lot of these, they cost about $600. They work very well.
Write back with any question you may have. I highly suggest a copy of my Conversion Manual, available by money order
or personal check for $59USD (add $15 for S&H outside the U.S.) payable to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802, or by credit card via PayPal at our Online
Catalog Page.
| | Subj: Corvair College Curriculum
| | Date: 1/31/03
Thanks for the new info. I have a question about bringing a motor to Corvair College. Do we
break them down, clean them, and rebuild them
there? Or do you start by taking motors that have already been broken down and cleaned?
If the latter, then I would just need to buy a
rebuild kit from say Clark's Corvair and bring a good clean motor?
Just wondering what all specific tasks are performed at the event. If you could send me a list
of what all is covered, I would appreciate it.
Thanks.
| | Greg, g_geer@blomand.net
| | Reply from WW:
| | The best thing to do is to bring a completely cleaned motor with all the replacement parts and a prepped crank.
We can assemble it at the event. We will not have the cleaning equipment from my hangar on the airshow sight.
| | Subj: Zenith CH 701
| | Date: 1/30/03
Hi, I was wondering if anyone has attempted putting a Corvair engine into a Zenith CH701? Plans state an installed wieght of 200 lbs.
Thanks.
| | Paul Hodgson, amehodgson@hotmail.com
| | Reply from WW:
| | The Heintz family has told me directly that they do not want engines which weigh 200lbs.
or more in the 701. Despite the fact that their 701 brochures have pictures of engines like O-200s and
EA-81s, which weigh as much or more than a Corvair, they do not encourage installations like this.
A number of people who liked the 701, but wanted to use a Corvair, are now working on an aircraft
called a Pegzair from Canada. You can find out more about it in the EAA Aerocrafter catalog.
| | Subj: Motors in Arkansas
| | Date: 1/29/03
How are you doing? I enjoyed very much the Jr. Corvair College in SA. Started looking for
motors immediately after and couldn't
come up with any. Finally, a guy in Houston sent my e-mail out to a list serve of
Corvair fanatics and a fellow in Little Rock, Ark.,
sent an e-mail. He will let me have 3 to 4 motors for $75.00 each; does this sound reasonable?
Also do the head numbers have to
match or will any of the recommended head numbers act as suitable pairs? I am ready to get
going on a motor and appreciate
your help! On your reply I will go to Little Rock to pick these motors up if you think this
is reasonable. He has indicated the motors
are complete w/o carbs.
Have a great day!
| | Ed Jones, xocouple2001@aol.com
| | Reply from WW:
| | Good to hear from you. The deal doesn't sound bad, but there may be motors closer to you. Dave Morris, who
ate dinner with us during the Alamo event, told me that there were several in his home town. I am sending out a roster
in the Winter 2003 Corvair Flyer newsletter of all the addresses of the guys at the Jr. College so everyone can stay in touch.
You may want to get in touch with Dave if it seems like a long drive for the motors you are considering.
| | Subj: Propeller Diameter
| | Date: 1/28/03
I discussed the possible performance of the Zenair CH 601 HD using the 100 HP Corvair engine
with Sebastian Heintz. He felt it probably
would work in the plane, but with a weight penalty. He advised using a prop with a diameter
of 68 to 70 inches and not less than 66 inches.
Again I would appreciate your feeling on the prop size. As usual thank you for taking the
time to answer my questions.
| | Paul Mallard, papaquack@aol.com
| | Reply from WW:
| | I have a lot of flight time on 68" Warp Drive props, and we have sold and flown 66" ones as well.
You can turn these props 3000rpm without them getting noisy and inefficient because they have very thin tip sections with
very high allowable mach numbers. These props are about $600.
| | Subj: Storch engine
| | Date: 1/27/03
I'm thinking of building a Storch type aircraft, such as a Preceptor Stol King or a Ragwing Stork RW-20. They need to swing a large prop. They need at least 100hp, big torque and weigh under 250 lb.
| | 1) Would a Corvair Engine work without a PSRU?
| | 2) Real Aircraft Engines have a special Main Bearing to keep the Crank in place. Does the Corvair?
Thanks!
| Gary Van Meter, gvanmeter@cox.net
| Reply from WW:
| | The Corvair does have a double sided main thrust bearing, which has a perfect track record of flying for the
past 42 years.
| | People have flown Corvairs with PSRUs, but they have a poor track record and none are available now.
They are non-existent because the motor works so well as a direct drive engine. There are no PSRUs available for
O-200s for the same reason.
| | The Ragwing is a very light plane and I am not sure it is approved for 200+ pound motors.
| | Subj: Fuel lines
| | Date: 1/26/03
One technical question. My Avid has all 1/4" fuel lines, from the outlet in the tank, through the header tank. Do I need to replace all
of those with 3/8" fittings? I think I know the answer, but thought I'd ask anyway.
| | Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
| | Reply from WW:
| | Yes, use 3/8''. You might get by with 5/16", but 1/4" will not work.
| | Subj: Vari-EZ
| | Date: 1/25/03
I am interested in a Corvair powered Vari-EZ project. I noted in your
Daily Q&A letters that you were working on a mount for a customer. What
is your current price for such a mount? May I contact the person you
made the first one for to get their advice as well? I am coming to
Sun 'N Fun & thought of making a side trip to your place of business
either before or after. Are you planning any Corvair Colleges around
that time?
I already bought your book @ OSH & look forward to seeing you again.
| | Michael Amick, Vari-Ez, Franklin, Tenn., mkamick@edge.net
| | Reply from WW:
| | The Vari-Ez installation that I worked on belonged to my neighbor Arnold Holmes.
However, Arnold and his father are planning to relocate to a grass strip, which the
Vari-Ez could not fly from. Thus, they have sold the Vari-Ez and put their full emphasis
into completing their Corvair-powered Dragonfly project. The Vari-Ez project was put on Ebay and
sold to a newly formed EAA chapter in Minnesota that is enthusiastic about completing and
flying it. The motor mount I built was custom made to fit the pre-existing cowl, and firewall
hard points. I did not build a jig for it, but it was similar in design to the motor mounts
that I build for Dragonflys.
| | Our Sun 'N Fun schedule is posted at News from the Corvair Authority.
All Conversion Manual owners are invited to build up their engines for free at Corvair College, just as
we've done at the past three Colleges. Everyone is always welcome to watch and learn. The only difference is that this
year's College is at Sun 'N Fun rather than at my hangar, and they charge
admission. Their Web site is www.sun-n-fun.org. Looking forward to seeing you in Lakeland.
| | Subj: Pietenpol Aircamper
| | Date: 1/24/03
I am hoping to build a plane
in the next couple of years and I am really interested
in the old, low and slow style of flying. I have a
question on the useful load of the Aircamper with the
100hp Corvair engine. Is the useful load of the
airplane controlled by the airframe structure, or by
the power of the engine? I am 250lbs. and would like
to take a passenger up with me. That doesn't leave
much for fuel. I am attracted to the Aircamper
because of the ease of construction and it being
primarily wood. If you would rather pass these
questions on to another group I would totally
understand. Are there other airframes out there that
you would suggest with similar ease of construction,
low initial cost, and perhaps a little more payload
available? I have read some of the other airplane
specs, but have also heard that talking to someone
with personal knowledge or exposure to these other
airplanes is invaluable.
| | Once again, thanks and I hope that I am not taking too
much of your time.
| | Tim Moody, Pietenpol, tj_moody@yahoo.com
| | Reply from WW:
| | The Pietenpol, if well built, can fly well above the
early published gross of
1150 pounds. Here is a good example: My plane
weighed 734 pounds, and truly
could have been 30 pounds lighter. My friend Gus who
weighs 280 flew
passengers who weighed 220 with 16 gallons of gas in
the tank. This is about
1330 pounds. The CG was within limits and the plane
flew well. The Piet is
one of a handful of planes which behave like this.
If you were putting a
lower power engine on it, the gross would be limited
by minimum climb
performance to a lower weight. At 1300 pounds, a good
Piet could still pull 4
Gs without damage.
| | Subj: Conversion costs, pistons
| | Date: 1/23/03
Hello Mr. Wynne,
A couple of questions: What is the estimated
cost of converting a Corvair engine, for the average
person, at this time? Also, how to know the
difference between cast pistons and forged pistons?
When they are in the engine, can it be done by taking
the head off and looking at the top of the piston, or
by taking the pan off and looking at the bottom?
Thank you very much for your time and trouble.
| | Ed Cody, #5259, mcalder_2000@yahoo.com
| | Reply from WW:
| | Good to hear from you. A forged piston will have the number L2206 on the head.
Most guys are spending $2800 to $3200 to completely overhaul and convert a motor, including a core.
| | Subj: Insurance for Homebuilts
| | Date: 1/22/03
There has been a lot of talk
about insurers not providing coverage for auto engined
homebuilts. This could be real trouble for us and I
was wondering what you thought?
Best wishes,
| | Mark Deacon, wrenchspinner1@yahoo.com
| | Reply from WW:
| | Several people have alerted us to the issue that the Corvair is not currently on Falcon Insurance's list of approved engines.
The Corvair has an excellent track record, and I am currently working to find out what Falcon's requirements are and gather documentation of
Corvair-powered flight to meet those requirements.
| | EAA HQ is very concerned about issues for grassroots aviation. I am quite sure HQ will urge anyone with their approved insurance
program to cover 100% of homebuilts which fly off their restrictions. It should be understood that there are great differences between auto
insurance coverage and aviation coverage. In my experience, auto insurance companies will always live up to their obligations, despite small
mitigating factors. Conversely, aviation insurance has a very hit or miss record. I have watched while companies like Avemco have paid out
obvious fraudulent claims, and then watched companies use the smallest of unrelated details to weasel out of legitimate claims. I personally
plan on carrying only liability insurance on my flights, as I do not believe that average insurance companies will pay hull claims on
experimental aircraft, even though their rates are extremely high.
| | Subj: San Antonio
| | Date: 1/21/03
Just a note to tell you how much I enjoyed attending the Corvair College in San Antonio. It got me reved up to get started.
I just swept out the old shop and rolled the table out that is supporting my '65 110 engine. On the way home, my son told me
he has the hots to get started too. Anyway, you will be hearing from me as things progress.
| | John Weikel, Kerrville, Texas, jandd@maverickbbs.com
| | Reply from WW:
| | Ttank you for the nice note We had a very good time ourselves.
| | Subj: Parts
| | Date: 1/20/03
I am one of the people in cold Michigan who is
getting started on a conversion of a Corvair engine. I will need one of
the distributors you modify, a prop hub and one of the aluminum oil
pans you mention in your Manual. I have my Chevrolet manual and my other books
you recommend about engines. At this point I am confused by all the
reading but I will work it out. You ask me to let you know if I found a
source of engines in this area; I got one in Bangor, Mich., from Jerry's
Garage. I didn't follow your advice and accepted one that was partially
dismantled. As you said, some parts are missing. So far I have not gotten
any response from the fellow I bought it from about changing for one
whole engine. I can't say I would recommend doing business with him
unless you are VERY certain you know what you are buying. On the other side
of the coin, I bought a complete engine from Clyde Stanton of Middleville,
Mich., and he is a pleasure to do business with; he has several Corvairs and
many parts for them. He e-mailed me that he is going to Florida and would
try to stop in to see you while he is there. If he does stop, you will
know him when you see his Corvair Motor Home he drives. I had never seen
one of those before. It would be fun to own one. I would like to see
either a picture or a drawing of how you mount your carburetors on your
manifolds; all the pictures I have seen so far are from the front of the
engine and do not show the carb itself. Let me know the way I can order
the parts I mentioned so I can get them here. Thanks,
| | Dick Van Fossen, evanfossen1@juno.com
| | Reply from WW:
| | Good to hear from you. Thanks for the tips on core motors; we have a number of guys in your area who have
asked for a source and we will pass the info along.
| | As for the parts:
| | Pan, $269
| | Prop hub, $319
| | Distributor, $219, and we need your old one as a core sent to 210-11 Cessna Blvd., Port Orange, FL 32168.
If you dont have it, add $45.
| | All prices include Priority, Insured S&H in the U.S. You can send a personal check payable to
William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802,
or use a credit card via PayPal at the Online Catalog.
| | Subj: Prop question
| | Date: 1/19/03
A prop question for you. I have a 3-blade Warp Drive 70" prop with standard hub. I hope I can
use it in a 2-blade format for my
Avid/Corvair. Can you sell me a high-HP 2-blade prop hub for my current blades? If the blades
turn out to be too long at 70", can
I shorten them or should I buy new shorter blades (like your 68")?
Thanks again.
| | Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
| | Reply from WW:
| | Yes, Warp Drive blades can be shortened. They are fairly easy to cut and smooth out, and
can be shortened from 72" well down into the 50"s. The material is of very uniform density, and
they will generally be balanced if you remove the same length off each tip. I am a Warp Drive
dealer, and can sell you the correct hub.
| | Subj: A Funky Corvair
| | Date: 1/18/03
William, I have a 1946 Funk that is supposed to have a C85-12 powerplant. I purchased the airframe from a gentleman that wanted
the powerplant. Thus I am interested in installing a Corvair auto engine. I scrounged up a Corvair engine about 14 years ago for
one of those some day projects. According to the engine serial # it appears to be a viable powerplant for conversion. However,
I would like to be certain it is a suitable engine for the Funk. What do you think? If so, I need to order your Conversion Manual and
get a liability release off to you so that I can get started on the some day project.
Thanks for your input.
| | Paul Peterson, Fargo, N.D., Peterson58104@cableone.net
| | Reply from WW:
| | You have a Funk airframe? They're terrible airplanes. If you give me your address, I'll
leave with a trailer tonight from Florida and relieve you of this burden. I couldn't allow a
fellow aviator to suffer with such an aircraft.
| | I'm just kidding. A Funk is a personal favorite airplane of mine. I always stop to get a good look whenever we come across one.
The only picture of a plane hanging on the wall in my shop is a Funk we saw last year at the SAA Fly-In at Urbana, Ill.
It is a very good match for the Corvair. You should look into how much rework it would take to get it to qualify as amateur built. Let me know
what you come up with.
| | Subj: Hand Prop Installation
| | Date: 1/17/03
If a Corvair motor were to be installed without a starter, could the flywheel be eliminated also? It seems like the prop alone should
have enough rotational mass to keep the motor running. What would the installed weight be of an installation like this? I would like
to build up a hand-propped motor with nothing more than a small lawn-tractor belt-driven dynamo for electrical power.
Thanks,
| | Doug, sputnik@aug.com
| | Reply from WW:
| | You are quite correct that the motor uses the prop for a very effective flywheel. The only type of "flywheel" I use is
a ring gear for electric starting. A motor set up as you propose could be brought down to 200 pounds ready to fly.
| | Subj: Smart Plugs
| | Date: 1/16/03
Can the standard 190 engine be ignited with smartplugs?
| | Jerry Plumlee, tplumlee@juno.com
| | Reply from WW:
| | Although I saw a Rotax 503 run a very convincing display on smartplugs, the last I heard they were still working on
four strokes. The operation is dependent on compression ratio, and must be specifically tailored to each engine.
| | I have worked several years to come up with a very reliable dual ignition system for the Corvair, and it is flight
proven in hundreds of hours in the air. Although smart plugs are interesting, I have little need to pursue another ignition system.
| | Subj: Front Starter
| | Date: 1/15/03
What are the part numbers for the:
Nissan ring gear for front starter?
Alternator drive pulley?
| | Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
| | Reply from WW:
| | All the front starter stuff is being redone to make it simpler and more off the shelf.
I want to get this wrapped up
in a month or two, but I will have parts that are much easier to find, and have the
brackets in stock.
| | Subj: Coils
| | Date: 1/14/03
Which coils do you use?
| | Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
| | Reply from WW:
| | The best coils are Bosh blue coils with the internal ballast resistor.
| | Subj: Suitable Aircraft
| | Date: 1/13/03
Hi William. I'm looking to build a two-place airplane on a limited budget. I recently came
accross your Web site and I'm very excited
about the Corvair conversion. I've narrowed my choices to the Littner Whisky IV, Sonex,
Nesmith Cougar and Sonerai II. I know
the Corvair can be used on the Sonerai. Do you know if any of the other designs can
use the Corvair? Any advice you can
give me will be greatly appreciated. Thank you.
| | John Minton, Kodiakmarine8550@aol.com
| | Reply from WW:
| | If you are looking for a plane which can be powered by a Corvair, you should look up the EAA Aerocrafter
manual; it lists all of the planes available in the industry. Look for all the ones which list an O-200 (100hp Continental)
as a good motor and this will be a good guide.
Write me back with any specific questions you may have.
| | Subj: Distributor Recurve
| | Date: 1/12/03
I have a rebuilt distributor that I got from Corvair Underground, with the points plate
removed. I read in your book that you will
re-curve my distributor for a modest price. I also need the bolts to mount everything.
If I ship my Dist. to you with the dual points
plate, the points rotor and cap, will you re-curve it for me? And how much will I need to
send you?
Thanks for your time
| | Fish Fischer, Ore., fishhole@pacifier.com
| | Reply from WW:
| | We now sell completely re-manufactured distributors, which precludes the need for getting
them from suppliers. The cost on these is $219, which includes Insured Priorty S&H. These are
complete with cap, rotor, etc. We need your old distributor as a core, or a $45 core charge.
| | Please note that I much prefer to work on our own distributors, but guys who already have a rebuilt
distributor body and want me to do the rest of the
work on it can for a limited time send it UPS to the hangar, 210-11 Cessna Blvd., Port Orange, FL 32128.
Cost breaks down as follows:
| | Points Plate $39
| | Points $20
| | Recurve $40
| | S&H $20
| | Total $119
| | Subj: Corvair Carb
| | Date: 1/11/03
Would a Corvair turbo carb be ok to use on a Corvair aircraft engine ?
Thank You
| | Dave Clark, Ga., Dclark356512@cs.com
| | Reply from WW:
| | The turbo carb has been flown on a naturally aspirated Corvair. But it's heavy, and expensive. There are a
number of other carbs I'd choose first. I discuss carbs in detail in the new Conversion Manual,
available by money order
or personal check for $59USD (add $15 for S&H outside the U.S.) payable to William Wynne, P.O. Box 290802,
Port Orange, FL 32129-0802, or by credit card via PayPal at our Online
Catalog Page.
| | Subj: Who can do repairs?
| | Date: 1/10/03
THE CORVAIR CONVERSION LOOKS COOL AND COST EFFECTIVE. WHO CAN DO REPAIRS ON THE
ENGINE? DO YOU HAVE TO BE "CERTIFIED"? I WANT TO BUILD A HOMEBUILT AND AM LOOKING AT
ENGINE OPTIONS. IF I DECIDE TO CONTINUE. I QUICKLY FOUND OUT THAT THE ENGINE CAN BE THE
MOST EXPENSIVE PART OF THE EQUATION.
| | NOTE THAT ALTHOUGH I AM NOT AN EXPERT, I DID DO 2 FORD 289s. IT WAS FUN AND THE SECOND
ONE RAN FINE. THE FIRST ONE FAILED BECAUSE I WAS TOO YOUNG/FOOLISH AND USED THE
WRONG SEALER ON THE OIL PAN.
| | PETE, Ptfoof@aol.com
| | Reply from WW:
| | Experimental aircraft are built and maintained, including the engines, by amateurs. None of the parts need to be
certified.
| | Subj: You've Convinced Me
| | Date: 1/9/03
I just ordered your Manual and tape yesterday, and I'm anxious to get
them. I'm building a Zodiac 601XL and just went through your Q&A pages and
was very pleased to see your remarks on the Corvair engine and the 601
combination. I have a 0 time O-235 engine sitting in my shop that I had
intended on using on my project, but started looking at other (less
expensive) engine options figuring I could sell my Lyc and help finance the
rest of my project.
| | I like what I've read in your Web page. I travel a lot to Florida in my
job, and hope I can perhaps stop by and meet you at some point. I'm only
about 2 hours from The Corvair Ranch in Gettysburg and have already
contacted them about paying them a visit. They quoted me $350 to $450 for
an engine. I called a local salvage yard where I have parked two Subarus
and one Toyota in the past, and they have several Corvairs, but they're not
sure what they have. I hope to go exploring tomorrow.
| | Anyhow, you've convinced me to sell the Lyc and build (or rebuild) my own
Corvair engine. I like the idea of knowing everything about the insides of
what will be flying in front of me in the future.
Thanks,
| | John A. Krumrine, Zodiac 601XL, State College, Penn., jqk4@psu.edu
| | Reply from WW:
| | Thank you for the nice words. Feel welcome to stop by the hangar anytime, but call to make plans as we are there
odd hours. We will get your Manual right out when the order arrives. Let me also encourage you to subscribe to our
newsletter, The Corvair Flyer. You will get a free copy with your Manual to look over.
| | An O-235 is a good motor and they bring a lot of money in good condition. Your plan will inject a lot of cash into
your aircraft project. There is a lot to be said for knowing your whole plane, including the motor.
| | You will find a lot of friendly people in the land of Corvair flyers. Welcome to the club.
| | Subj: Distributor
| | Date: 1/8/03
I spoke with you last week about a rebuilt distributor. I have my distributor packaged and
ready to send. Do you have a
UPS shipping address that I can send it to?
| | Chuck Snyder, Greenbrier, Ark., rgilliom@alltel.net
| | Reply from WW:
| | You can ship it to the hangar address, 210-11 Cessna Blvd., Port Orange, FL 32128.
| | (Everyone, please take NOTE: The Port Orange USPS somehow recently seceded from Daytona
Beach, and at some point will end the grace period for delivering mail that is not addressed
to the hangar as "Port Orange." So please note the change to Port Orange in your address books.)
| | Subj: Spark Plug Removal
| | Date: 1/7/03
Greetings William!
Thank you for bringing some excitement in building a KR2S. I had the plans since '83 and
finally am starting on it: Engine First! I am in no rush
and started to break down a 66 RH engine that I recently purchased and broke one of the
spark plugs in the hole. Easy-outs do not budge it
even with a breaker bar. Any suggestions?
| | Richard L. Cowles, KR2S, Madison, Ala., richardcowles@knology.net
| | Reply from WW:
| | Try either Kroil or Mouse Milk. These are two extremely good penetrating oils. Failing this, heat it with a propane
torch and melt a wax candle into the threads. When it cools, it may be loose. If this fails, heat the head in an oven at 400F for
an hour. Use a turkey baster and pour cool water through the plug threads.
| | Subj: Corvair engine for high elevation use
| | Date: 1/6/03
I am interested in knowing if your engine is suitable for me. I live in
Bogotá Colombia South America. I am thinking (1st time builder) of
constructing a 2 seat airplane or biplane that will be able to fly
here. The elevation in our city is of 8,355 feet MSL (really, check out
a Jeppessen chart for apporaches into Eldorado Intl Airport).
I know of a lot of people flying behind Rotax 912 engines here but I
believe they are expensive and underpowered.
I am looking at a biplane because of the ample wing area (double) and
because I do not plan to cruise at mach numbers!! I am also interested
in the KR2S and own a set of plans for a SuperKingfisher 2 place
amphibian.
| | My questions relate to:
| | 1) Will I be able to build (rebuild) a Corvair engine?? (Would it be
better for me to purchase an already rebuilt engine from you?)
| | 2) Will it function reliably at my elevation/altitude?
| | 3) Would I need any sort of boosting and /or is it desirable?
| | Flight schools here mostly fly Cessna 152s powered by O-320 150 hp
engines on x country flights and usually climb up to 10,000 ft to depart
through mountain passes. This is a power to wt ratio of approx 10.25
lb/hp. (I know this from fact, as I validated my commercial and private
pilot's license here in one of these, with a 180lb instructor and
myself @ 150lbs + 39 gal of fuel! Climb rates were low, but got us
through.)
| | I have looked at several kits as well as plans and might go for plans
because of the lower initial cost of building the plane. I also was
considering the Hirth http://www.recpower.com/f302c11.htm
2-cycle 110hp engine which claims to do this at about 5600 rpm and
weighing in at about 120 lbs (!!). However, it seems to be more
expensive than your Corvair. Do you think that a 2 cycle engine will
really output such hp?
| | I have looked at planes such as the Fisher Celebrity, KR2S, Ragwing
Special II. What would you recommend?
| | My mission profile is to fly around the patch, with my kid (father of
one, soon to be two!) or wife, sometimes shoot very short x country
flights of about 1 hr, 100 mile range, mostly above the mentioned
elevation.
Temperatures year round vary between 0 and 22 degrees centigrade, very
dry air, average temps between 12 and 18°C about 85% of the year.
Can it be done or should I just switch to golf??
| | I am already involved in aviation as mg of charter flights for a TAMPA
Airlines cargo. Our CEO graduated from your school but from the Arizona
campus, I believe. I went to FIT in Melbourne where I got my pilot's
license. Wife flies as flight attendant for AA so I want to start flying
light planes again for fun and slow flight enjoyment.
My best regards, and a very happy new year.
| | EFRAIM, Bogotá, Colombia, eotero@tampacargo.com.co
| | Reply from WW:
| | Thank you for your very nice note. Your questions are very well thought out and reasonable.
One of our projects this year is to turbocharge the Corvair motor for flight. As you know, many Corvairs were turbocharged
from the factory. They were the first mass produced turbo cars in the world. We are working on a motor which will use a
modest 6 pounds of boost. I would estimate this to add about $1,000 to the cost of a conversion.
| | Anybody who can build a plane can convert a Corvair motor successfully. Do not worry about this. We've sent
parts worldwide, and have never had a problem with customers being able to order directly from suppliers in the U.S.
When evaluating an airplane, especially for high altitude work, the crucial feature is span loading. This is gross weight divided
by wingspan in feet. Compare a couple airplanes that you know and you'll see as long as they have similar power loadings,
the ones with lower span loading will fly much better in thin air. We've done a lot of flying with a density altitude near 5,000 feet
and the naturally aspirated motor works well here. For local flying, a Pietenpol with a few more feet of wingspan would beat
any light biplane for efficiency. You may want to consider this design.
| | I've only been to your country once, for a single day in Cartegena. I've met a number of very nice people from Colombia.
Every one of them spoke lovingly of their home country.
| | Subj: Corvair to Italy
| | Date: 1/4/03
I WRITE YOU FROM ITALY AND I'D LIKE TO BUY AND TO KNOW HOW MUCH ARE:
| | 1) A CORVAIR ENGINE, 3100cc 120hp, COMPLETE AND CONVERTED FOR AIRCRAFT USE, NEW AND USED.
| | 2) A CORVAIR ENGINE TO ADAPT TO AIRCRAFT USE WITH ALL THE COMPONENTS FOR CONVERTING IT.
CAN YOU HELP ME?
BEST REGARDS
| | mitt.MARINI GABRIELE, Italy, info@vetreriagorbini.it
| | Reply from WW:
| | My main business is teaching people to build Corvair motors. I build very few complete motors. I can provide all the
parts to convert the Corvair for aircraft use, and show you where to buy all the standard rebuild parts. If necessary, I can
find you a good rebuildable core motor to work with. A rebuildable core with crating and shipping is approximately $1,000USD to
Europe. The parts to overhaul this motor are about $1,500USD, and the components to convert it for aircraft use cost about
$1,500USD additional. The 3,100cc motor is a very special conversion that requires significant machine work and very careful
custom assembly. It is a much more difficult motor to build.
| | Subj: Corvair vs. Jabiru
| | Date: 1/3/03
I just came across your Web site tonight--- very interesting. I am
scratch building a Zenith CH 601XL. (Earlier I had built and flew
(300 hrs) a Zenair CH 701, Rotax 582.)
I have been planning on installing the Jabiru 3300-- 6 cylinder- 120
hp.----- I really like the engine (except for price), but just found out
one thing which I am very concerned about; IT HAS NO HEAD GASKET !!
I think this is not good, as the cylinder block is machined from 4140
and the heads are machined from aluminum. Two dissimilar metals which
expand at different rates. The 3300 hasn't been out very long, the
2200 has been out for a while without any problems in this area, (that I
know of)---- I can't spend over $11,000 for an engine to find out that
at 500 hrs the heads might warp------- I know Jabiru wants the heads
torqued rather frequently.--------- your thoughts on this please-----
I like the "fly-away weight" of the Jabiru vs. the Corvair
engine------- I wouldn't mind the extra weight of the Corvair engine
for the dollars saved --- I guess I'm asking, "can you tell me if this
is a major concern, and should I strongly consider the Corvair engine
for this plane"----- I had a friend who started building the CH 601HD
and was planning on putting a Corvair engine in it, but gave up on
the idea as he is remodeling his house.-- He tried to "sell" me on
Corvair engines earlier------- In advance, thank you so much for your
time- and I'll put more time into researching your info----
| | Fritz Gurschick, Zenith CH 601XL, Turner, Maine, klondike2@midmaine.com
| | Reply from WW:
| | Good to hear from you. Despite the fact they don't have head gaskets, Jabirus seem to be good motors.
Of course, their primary problem is the arm and leg cost. The Corvair motor does typically weigh 35-40lbs. more. But the 601 is
certainly capable of carrying either motor. My honest guess is that a 601 could be plans built with a Corvair motor for the same
cost as buying a 3300 Jabiru.
In the coming months, we'll be doing more work to develop this installation. Watch our Web site for details.
| | Subj: Gauges
| | Date: 1/2/03
What brand oil pressure and temperature senders and gauges do you recommend?
| | Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
| | Reply from WW:
| | I use Autometer gauges. Go to your local performance auto shop and you will see that they offer them in both electric
and mechanical and in a number of face styles.
| | Subj: Copper washers
| | Date: 1/1/03
Where do you get soft copper washers for plugs?
| | Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
| | Reply from WW:
| | McMaster-Carr or any other of the industrial supply catalogs have them. My local hardware store has them in the
Weatherhead line.
| | Subj: Copper washers
| | Date: 1/1/03
Where do you get soft copper washers for plugs?
| | Dennis Smith, Avid Flyer, Lebanon, Ore., famflier@centurytel.net
| | Reply from WW:
| | McMaster-Carr or any other of the industrial supply catalogs have them. My local hardware store has them in the
Weatherhead line.
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