William Wynne

"The Corvair Authority"
Mail to:
Sport Performance Aviation LLC
Attn: William Wynne
1528 Virgils Way, Suite 8
Green Cove Springs, FL 32043

November-December 2003 Daily Question & Answers

NOTE: Due to popular demand, we've split this page into smaller pages to make it faster to load. Those of you who have DSLs or cable modems can still view all the 2003 questions on one page at:

The 2003 Daily Q&A Page, which will be updated monthly.

To search for anything on any of these Web pages, the toolbar on the top of your browser has an Edit function with a Find on this Page feature. Just type in the key word in which you're interested, and the Find feature will take you right to it. If you don't see your question answered here, or at one of the following pages,

October 2003 Q & A Page

September 2003 Q & A Page

August 2003 Q & A Page

July 2003 Q & A Page

January-June 2003 Q & A Page

2002 Q & A Page

then by all means e-mail William at WilliamTCA@FlyCorvair.com. Thank you.

Subj: Hiatus
Date: 12/31/03

Thank you all for tuning in to the Daily Question and Answer Page. We've put this page on hiatus while we concentrate on completion of the Zenair 601. Those of you who subscribe to The Corvair Flyer will be receiving an update shortly. We'll also post any big news at The www.FlyCorvair.com News page. We hope to see you all soon. Of course, we're still answering an average of 20 private e-mails a day. It can just be done a lot faster without editing for page posting. Happy building and flying.

Subj: Gary Coppen's Skycoupe
Date: 12/30/03

Do you know what the typical cylinder head and oil temperatures are on Gary Coppen's Skycoupe? The pictures on your Web site of this particular engine installation are remarkable for their lack of clutter on top of the cylinders which, I imagine, makes for a good down-flow of cooling air. Where is the oil cooler in this installation? Regards,

Paul Madden, pmadden@draper.com
Reply from WW:
This engine is typical of Corvairs converted according to my Conversion Manual. It runs 320F in cruise, up to 400F in sustained climbs. The oil temperature is 210 in cruise, peaks about 230F. The front starter arrangement allows for a completely stock oil system, including the stock cooler, which is on the right rear corner of the motor when viewed from the propeller. Thank you for the kind compliments on the installation. I did it in my shop. I strive for simplicity, and neat appearance.

Subj: Engine disassembly - defeating frozen studs Ways & Means?
Date: 12/29/03

Is there any better way to tackle disassembling these backyard gems that have waited just a little too long to see a wrench that cares, now twisting on frozen studs?...

Your Web site and Corvair knowledge are a treasure... With much appreciation,

Steve Kiblinger, SKiblinger@cs.com
Reply from WW:
One product that works exceptionally well is Kroil. It's available from Aircraft Spruce. Try tightening the stud a minute amount first. You can always heat the nuts with a propane torch, and wick in birthday candle wax. Capillary action will pull it inside and make it easier to unscrew.

Subj: 601 Install Kit?
Date: 12/28/03

Another e-mail just to say thanks. And to let you know that I, for one, am hoping that you might consider a kit type of install for those of us who are ignorant of a lot of the engine matching of carbs, manifolds, where to install manifold pressure gauge, CHT, EGT, etc., etc., or perhaps a specific sheet with that info for those of us going the Corvair/601 route: a basic here's the exhaust, here's the intake manifold, the alternator bracket and the alternator package, or at least a parts list and drawings. I don't mean to presume on your good nature. I am sure there is a way that you can be compensated, at least I would be willing, since all of this stuff is new and I need guidance. Without you, I would not even consider this type of project, so, again, thanks. All my best,

Jim Dankovich, Zenair 601, Troy, Mich., jdankochiro@yahoo.com
Reply from WW:
I will be using an MA3-SPA carb on our 601. I think it is the best way to go. An Aerocarb would work also, but I am partial to float carbs. I will outline the whole 601 fuel system on our 601 Corvair Flyer Web page when we get it done, in case you want to follow along.

Subj: Oil Pan and top cover thickness
Date: 12/27/03

Do the Oil Pan and the Top Cover contribute significant strength to the engine case? Is there a minimum thickness you would recommend? How thick are your pan and top cover? Thanks,

Bill Wright, william_wright@wlbeng.com
Reply from WW:
The Oil Pan and Top Cover do not contribute to the strength of the case. The thickness is based on two things: The Top Cover needs to be .125" thick. Less than this will not effectively keep the gasket in place when a front mount starter is used. You could get away slightly thinner with a rear starter, but real thin pieces distort under the bolt heads and are prone to leak. On the Oil Pan, the rail is made of .125" and the box which forms the sump is .050". I consider this the minimum thickness desirable. You might go thinner if you used area washers under the heads of the bolts, but you would lose some of your weight advantage with the additional hardware. An oil leak at the pan level is serious business; it will make a big mess, and potentially drain most of the oil from the engine. I have flown this stuff a lot. The cover and pan are really part of the oil system, and not the place to be looking to save weight on the motor. We have gotten the stuff down to what I think is the minimum most people should consider.

Subj: Pitts Powered Corvair
Date: 12/26/03

Have you had any experience with Corvairs in Pitts Specials? I am building a Pitts S1C, and the early Pitts used 100 to 120hp engines (O-235 or O-290 Lyc.). Sunny Sunday morning flying will be the main use. Aerobatics are not intended at this stage. I am trying to build down to the weight of the early Pitts (later ones using 180hp to 200hp are up to 50% heavier) and the weight of the Corvair engine is particularly attractive for achieving this goal. I would appreciate your comments. Regards,

Dennis Emms, demms@bigpond.com
Reply from WW:
An early flat wing Pitts would fly with a Corvair. You are very right that most of them are too heavy. A friend of mine built an S1S, IO-360, metal prop, electric start (no alternator), aluminum geared, and it weighed an honest 808 pounds painted. Most planes never get near this. A very light S1C, built with this same philosophy, could be Corvair powered. I have a lot of respect for the designs of CP. They are strong, reasonably simple, and good flyers.

Subj: RB Engine, Zenair
Date: 12/24/03

Holiday greetings to you and yours! I just bought your book, but I'm visiting relatives in Ohio and I don't have it with me. Thanks for getting back to me so soon. Should I assume that your endorsement of the '65 Corsa engine cases for an airplane means they will be compatible with an 8409 crank, 10-10 cam, and other conversion components? By the way, I hope to purchase the Zodiac 601 kit, maybe by summertime. Did I understand correctly that you were able to buy major components such as the fuselage and wings pre-fabbed by the factory? Thanks. Next trip I'll bring the book - ya never know!

Doug Jamison, jamahaus@yahoo.com
Reply from WW:
RBs are true 1965-66 Corsa engines. Their bottom ends make good airplane motors. They do not have the 140-auto trans timing gear issue, because no Corsa ever had an auto trans. If available at a good price, buy them. An RB has an 8409 crank, and all Corvair motors can have an OT-10 cam installed. All of my conversion parts can be fitted to any model of the motor.

Our plane was slightly more prefabricated than the standard kit. It was the factory demonstration piece at Oshkosh. The kit is inexpensive to ship because it can be put in flat packages. No 51% kit can come with parts like wings finished. Ours were in kit form, and they have proven to be very easy to build.

Subj: Alternator
Date: 12/23/03

I have ordered your Front Starter Kit and Alternator Pulley from the Online Catalog today. I have made up my mind to do it the right way and make this Piet an electric start. The only question I have is, will the small alternator bracket in the Manual work with the starter kit I've ordered? Merry Christmas and a Prosperous New Year,

Gary Bell, Manual 5151, Pietenpol, Delaware, Ohio, glbell@midohio.net
Reply from WW:
Thank you for your order. The alternator bracket in the Manual is designed to work with a Kubota 14amp alternator. Today, most people are using the John Deere 18amp model which is slightly larger. We'll have the new drawings for this mount available shortly after the first of the year. Both are compatible with the Front Starter Kit, but I'd suggest you go with our new model. We're out of town right now, and we'll ship your Starter Kit when we get back after the New Year.

Subj: Corvair in CH701
Date: 12/22/03

Can the Corvair be used in the Zenair CH701?

Reply from WW:
The Heintz family tells me that the 701 was engineered for lighter motors. Although they have flown with engines like the O-200, which are in the same weight category as the Corvair, the family feels that 701 builders should really stay with lighter motors.

Subj: Cassutt and Corvair
Date: 12/21/03

How would a Cassutt do with a Corvair?

Reply from WW:
I have done two installations of Corvairs into Cassutts, and they fit fairly well. The motor is shorter and narrower than an O-200. For reasons to do with people (marriage, money, etc.), not machinery, these two builders are on a very slow pace. Overall it is a good match, as long as you are not interested in hard acro work, as you said. Write me with any questions you may have.

Subj: Dutch Corvair Engine
Date: 12/20/03

I am going to build a KR2S and did some reading into suitable engines. I have read a lot about builders with Corvair engines and they are very happy with them. So I have a great interest in getting one myself. That is why I mail you. Every article I read shows me back to your Web site. It really looks like you know these engines.

I live in the Netherlands and I do not know of any Covair engines for sale. My question to you is if I would like to get one of these engines, is it possible to do it true to you? What would you suggest is the best thing for me to do? What engine do you think is the most suitable for the KR2S? Can you just give me a general idea of possibilities or if it is not possible let me know. If it is possible, at what cost will I be looking at if you would build an engine for me?

It is not that I am ready for an engine now, but I would really like to know what I can or can't do. Excuse my English but this is not my strongest point. Greetings,

Peter Waijenberg, KR2S, Netherlands
Reply from WW:
Your English is 1,000 times better than my Dutch. Your e-mail was very clear. We've exported engines all over the world. We can send you a rebuildable core or a completely overhauled engine. Crating and shipping on either motor is about $500 to Europe. Rebuildable core motors start at $299. A completely overhauled and test run engine with electric start and ignition system but no carburetor or exhaust is about $6,000. The cost in parts to overhaul and convert the motor yourself is about $3,000.

Everyone starts with one of my Conversion Manuals. You can order one from my Web site at The www.FlyCorvair.com Online Catalog, or you can mail us a money order for $74USDollars payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129 USA.

The Manual contains a lot of information on fuel systems, and other topics related to the airframe and preparing it for the engine installation. I also sell motor mounts for the KR. It is a great match.

Let us know how we can help you with your airplane building plans.

Subj: Corvair in Murphy Rebel
Date: 12/19/03

Would you know of anyone using the Corvair engine on a Murphy Rebel Kit aircraft? Just curious. Great Web page!

R. Wayne Moore, MOORERW@cpchem.com
Reply from WW:
We have had a number of guys talk about it, but I don't think one has flown yet. It is a very nice plane, and I distinctly remember being impressed with it the first time I saw one in person 10 years ago. I am sure that a Corvair could power one nicely.

Subj: Corvair in Vans RV-9
Date: 12/18/03

You have stated that the Corvair engine is not a good engine for the Vans line of aircraft. You also state that the Corvair may be used to replace the O-235 Lycoming. The RV-9 and RV-9A can use the O-235 Lycoming engine. My question is, can the 190cid Corvair engine be used on the Vans RV-9 aircraft? And does your Manual cover turboing the 190cid Corvair engine?

Harold G. Mothersill, lmothersil@aol.com
P.S. Love the information on your Web site. It may make it affordable for me to build and fly my own aircraft.
Reply from WW:
The RV-9 is certainly a fine aircraft, and I saw the picture in Sport Aviation of the one flying on a 100hp O-235. But I did note that the second one the factory built had an O-320. Most of the ones I've seen in the field also have O-320s.

While a large displacement Corvair can do the work of an O-235 in some airframes, particularly ones where propeller diameter is restricted, and there's an opportunity to use the Corvair's higher rpm potential, it is not a direct replacement for an O-235 in all situations. Additionally, a 190cid Corvair motor is potentially 50 pounds lighter than an average O-235, and may actually present a weight and balance issue on an aircraft like an RV-9.

If you've not made up your mind which metal airplane you like, but the economy of the Corvair motor appeals to you, I would suggest checking out Zenair's 601. While the airframe kits are roughly the same cost, the 601 is vastly easier to build, a lighter plane, and with a lower horsepower requirement, is a perfect match for the Corvair motor. You can check our progress on our own 601 at The www.FlyCorvair.com 601 Web page.

Subj: Corvair in Gyrocopter
Date: 12/17/03

I had the pleasure of talking to you during Sun 'N Fun, and with all the questions I asked you about Corvair engines, I forgot to ask the most important one: Can a Corvair engine be used on a Gyrocopter? I currently have a Benson Gyrocopter with a MAC engine and would like to replace it with something more reliable and easier to start. Thank you for your help.

Phil Tua, ptua@airtranairways.com
Reply from WW:
The Corvair engine has been used in Benson style gyros since 1967. However, it has not been a common installation like the MAC or other engines. The Corvair's double sided thrust bearing allows it to be used as a pusher. It is capable of developing substantial power, especially when used with a smaller diameter prop, like a gyro.

Subj: Corvair acquisition success
Date: 12/16/03

Your advice about finding an engine was a big help. I believe I've found an engine within 100 miles of me. Would it be prudent for me to get 2 of these engines (just in case!)? Thanks again for the great WEB site!

George Nelson (US Army, Retired), Magazine, Ark., smokie@arkansas.net
Reply from WW:
Many of our customers report finding an engine for $100, with a second one available for $50 or so. If offered a deal like this, I'd take the second one also. Corvairs have very good parts interchangeability, and a second core engine is good for mocking up engine mounts and cowlings.

Subj: Moveable Corvair College
Date: 12/15/03

My name is Tim Hendrix and I live in Rockport, IN. I am considering building a Pietenpol AirCamper and powering it with a Corvair engine. Is there any Corvair engine that is not well suited for conversion? I don't know a lot about them yet, so I thought I would ask. I have yet to locate an engine locally, but I am still looking. I just wanted to ask so when I do find one, I won't be getting something I can't use.

I have enjoyed your Web site and look forward to purchasing your Conversion Manual soon. Do you have a schedule for upcoming Corvair College dates and do you ever hold any close to Southern Indiana? Thanks for any info. Sincerely,

Tim Hendrix, Rockport, Ind., timandnanh@psci.net
Reply from WW:
The engine you're looking for is a 1964-69. Early motors are only 145cid and are not worth pursuing. The Conversion Manaul contains all this information in great detail.

We are contemplating another Corvair College in the middle of 2004 in the central U.S., but have not firmed up the date yet. We'll post the latest on Colleges at The FlyCorvair.com News Page.

Subj: Engine
Date: 12/14/03

I received the Corvair Conversion Manual and immediately read through it twice. Then I began a search for an engine core, using the resources suggested. I called all the wrecking yards here in Alaska, and they only laughed at me. I finally found only one Corvair with engine, but not for sale. I began scouting along all the back roads looking in yards, but with no success. So I then began searching the Internet, as well as wrecking yards on the West Coast. I did locate two engines in Vancouver, WA, with a cost of nearly $1,000 for cores, including transportation to me. As one final desperate attempt to find something closer, I ran an ad in the local paper. Wouldn't you know it - a gentleman called up who lives not more than 20 miles from me with just what I needed. It's just as you said, probably one is closer than you think. You just have to look. Thanks for the encouragement to start this interesting project.

Wendell Downs, Alaska, downswl@mtaonline.net
Reply from WW:
When you fly your Corvair powered plane to Oshkosh, I'm going to put you on the stage in The Theater in The Woods so you can tell this story to everybody. I've said it a million times, but the story of your engine search is certainly one of the better ones. It goes a long way to show how common Corvair engines really are. Thank you for sharing.

Subj: Bushcaddy L120
Date: 12/13/03

The Bushcaddy L120 would seem an ideal candidate for a 100-110 HP Corvair engine since the parent company, CLASS, recommends an O-200 for this service. Regards,

Moe Baxter, myb8@sympatico.ca
Reply from WW:
I've not seen a Bushcaddy in person. But a number of our customers have, and say they're very impressed with it. We have five or six Corvair guys who are either working on this plane as their airframe, or have said it is in the planning stages for them. The Bushcaddy Web site indicates 220 pounds as a maximum engine weight, but also lists a Lycoming O-235, which is 40 pounds heavier than this, as an engine option. Standard Corvair motors are fairly close to the 220 mark, and would probably power this aircraft nicely.

Subj: Vans RV-9
Date: 12/12/03

You have stated that the Corvair engine is not a good engine for the Vans line of aircraft. You also state that the Corvair may be used to replace the O-235 Lycoming. The RV-9 and RV-9A can use the O-235 Lycoming engine. My question is, can the 190cid Corvair engine be used on the Vans RV-9 aircraft? And does your Manual cover turboing the 190cid Corvair engine?

Harold G. Mothersill, lmothersil@aol.com

P.S. Love the information on your Web site. It may make it affordable for me to build and fly my own aircraft.

Reply from WW:
The RV-9 is certainly a fine aircraft, and I saw the picture in Sport Aviation of the one flying on a 100hp O-235. But I did note that the second one the factory built had an O-320. Most of the ones I've seen in the field also have O-320s.

While a large displacement Corvair can do the work of an O-235 in some airframes, particularly ones where propeller diameter is restricted, and there's an opportunity to use the Corvair's higher rpm potential, it is not a direct replacement for an O-235 in all situations. Additionally, a 190cid Corvair motor is potentially 50 pounds lighter than an average O-235, and may actually present a weight and balance issue on an aircraft like an RV-9.

If you've not made up your mind which metal airplane you like, but the economy of the Corvair motor appeals to you, I would suggest checking out Zenair's 601. While the airframe kits are roughly the same cost, the 601 is vastly easier to build, is a lighter plane, and with a lower horsepower requirement, is a perfect match for the Corvair motor. You can check our progress on our own 601 at The www.FlyCorvair.com 601 Web page.

Subj: Corvair Horsepower
Date: 12/11/03

How many HP can the Corvair engine produce?

Duane Davis, Universal City, Texas, Tankboot@HotMail.Com
Reply from WW:
The Corvair motor can reliably produce 100-125hp as a direct drive powerplant. This depends on what displacement you use. Additionally, I'm working on turbo versions of the engine, which have the potential to increase this by 15-20% and retain this level of power to 10,000 feet. The Corvair motor is a very strong design. Engines built for drag racing have recorded in excess of 450 rear wheel horsepower on stock crankshafts and engine cases. Engines with stock connecting rods have exceeded 350hp. While these are short durations, it is an indication of how we have de-rated the engine to obtain reliability. The Corvair is the only automotive engine I can think of where we actually ask less hp of the engine than the automotive use was rated at.

Subj: Canadian Corvair Pietenpol
Date: 12/10/03

I have been going over your Web page and find it very interesting to read. I am building a Pietenpol aircraft and have built the short fuselage with the intent to install a Model A Ford.

But I have changed my mind and I am very interested in the Corvair engine. Finding a block up here seems to be a hard thing to do. But here is what I want to know...can I build just a simple Plane-Jane engine? Nothing special, I just want to hand prop it! And have it not cost me an arm & leg, so to speak. I have an aviation parts business up here. You would think I could get cheap parts for an O-200 up here - not likely. The Corvair looks like the way to go. I just want it simple and reliable. Can you help to guide me in the right direction!

Bill Budgell, Pietenpol, Canada, wbudgell8965@rogers.com
Reply from WW:
Bernie Pietenpol was an aviation entrepreneur just like you, but still he chose the Corvair motor every time he built an airplane after 1965. I have to think he had access to a lot of 65 and 85 Continentals, but never used one. Our Pietenpol airplane was originally Ford powered for a few hours in the 1960s, but was then converted to Corvair power for the rest of its life. I like the sound of A motors, and they're fun. But there's just a lot more utility to be had out of a Corvair engine. Somewhere between 8-10% of our customers are from Canada, and for the most part, they've all been able to find good core motors to work with. A complete overhaul and conversion of a hand-prop motor has been done for less than $1,500. There simply is no other bargain quite like this in aviation. Our simple Front Start Systems are retrofittable to hand prop motors built from my Conversion Manual. They are not heavy, nor exceptionally expensive. I like them on a Piet because it is not the easiest plane to get in and out of, and being able to start it from the inside is nice. Let us know how we can help.

Subj: Engine Mount Delivery for 601XL
Date: 12/9/03

After reading through your Conversion Manual, I've decided to proceed with the Corvair for powering my 601XL. This leads me to ask about the approximate lead time and cost for the Engine Mount for the 601XL?

Thanks for writing a no nonsense, easy to read Manual.

Bill Cribb, Zenair 601XL, N601WC (reserved), wscribb@centurytel.net
Reply from WW:
We have several 601 Motor Mounts in the works right now. I intend to finish them in time for Christmas (we just moved into a brand new 4,000 square foot hangar and we're just getting the tools organized). I plan on working through Dec. 22 to get out every order.

I've built about half a dozen Mounts for 601s already. This tune up period allowed me to perfect the jigging, and come up with an accurate number for the time and materials involved, etc. Our price for 601 Motor Mounts is $589. This price includes all the polyurethane bushings to mount the motor, the actual AN hardware to mount the motor itself, including the nuts, washers and cotter pins. The Motor Mount is shipped unpainted. It has a light coating of oil, so it will not rust. The cost of shipping and handling varies with each address. Most of the mounts I've built over the years have gone out by FedEx ground. It is typically $40-$60 to ship one. They are very light, but they are subject to an oversize charge. Let us know whenever you're ready. You can simply send a check made payable to William Wynne, P.O. Box 290802, Port Orange, FL 32129-0802, or pay by credit card via the www.FlyCorvair.com Online Catalog.

Subj: Sport Pilot 601
Date: 12/8/03

I am very interested in your Zenair 601XL with Corvair engine. I am wondering if this airplane and engine combination would be a good candidate for the "Sport Pilot" category. Do you have any idea what the finished airplane's empty weight will be? The Corvair engine is a bit heavier than the Rotax 912 that Zenith is promoting as the best choice for Sport Pilot (because of its light weight). I'm wondering what the useful load will be using the proposed 1232 pound gross weight that the Sport Pilot proposal allows. Your thoughts are appreciated. Thanks,

Rob Fierberg, rfierb6707@hotmail.com
Reply from WW:
The XL model of the 601 was designed from the beginning for the proposed Sport Pilot category. As our aircraft is not complete, I cannot tell you exactly what the empty weight will be. The factory airplane has a full panel and a number of items which may make the airplane weigh a bit more than average. We're shooting to bring our airplane in at 732 and retain a 500 pound useful load in the category. Watch our www.FlyCorvair.com 601 Web page as we make further progress on this airplane.

Subj: Distributor Recurving
Date: 12/7/03

I have a distributor that would need re-building/curving. I live in Winnipeg, Canada. I will be in Miami, Florida, on May 1st next year and would like to pick up the rebuilt distributor there and avoid the shipping/handling/brokerage/tax/etc. charges. Questions: How much lead time do you need to re-build and test the distributor? Would I get the same one back or would you just store the one I send as a core? What kind of condition must it be in when I send it to you? What do I tell the security people at the airport when the distributor goes through the x-ray machine? Thanks. Clear Skies!

Martin Bima, STOL-Vair, Winnipeg, Canada, mbima@hydro.mb.ca
Reply from WW:
We're about 240 miles north of Miami. It is an easy four hour drive on the Interstate if you'd like to visit. I keep dual ignition distributors in stock. I can redo yours, but it's much easier if we exchange it. I can generally re-use something from every Corvair distributor we get. Even if it looks pretty grimy, send it. It doesn't need to have a cap, vacuum advance or points plate. We carry aircraft parts around the country all the time, and never have a problem with this. If you look at my safety shaft design, at first glance, it must look suspicious in an x-ray machine. Yet, we've had no problems traveling on airlines with these parts after they're inspected for a minute.

Subj: Corvair engine in Ercoupe
Date: 12/6/03

Have you ever heard of an Ercoupe with a Corvair engine? Is it possible? Feasible? I had a '67 Corvair convertible totally restored quite a few years ago. I'm looking at buying a two-place airplane and am not sure if I want to go with a homebuilt or not. In the non-homebuilt category, the Ercoupe is in my price range. Some I've seen are projects with no powerplant. Just wondering what would be involved in putting a Corvair powerplant in an Ercoupe.

Steve Roberts, Claymont, Del., dvcsteve@comcast.net
Reply from WW:
It is not easy to get FAA approval to put a non-certified motor on a certified airframe. If you pull it off, the airplane will have to be flown in a restricted flight category which likely will not allow passengers or flights outside your area. While a Corvair would certainly power an Ercoupe nicely, it would not provide you with a very useful aircraft. My best suggestion is continue looking for a homebuilt of your choice.

Subj: 'Vair Powered Piet Update
Date: 12/5/03

Hope all is well with you both. The (wood frame) Piet is going well. I decided to rehab the landing gear and wheels I bought from you after all. The cable/drum brakes are really just for run ups anyway. Got any idea where I can get replacement brake shoes? I'm real close to having the fuselage up on the gear. Also, I think we have taken care of the flywheel/starter issues after a good bit of "toothy" research (we have a love/hate relationship at NAPA now, just kidding...). Gonna lay a good one on you: We're looking into testing an updraft carb for the 'vair in just a bit. It's 35mm with a choke and standard float and made by Holly and they are fairly reasonable. Yup, leave it to a farm boy. The Ford 3000 gas tractor uses this carb and all indications are that it should work just fine. To start the break-in period though, we're going to mount the stock two carbs, synched, while I work out the tubing for intake system. I'm finishing out the rest of the "systems," i.e. charging, starter and monitoring instruments. Well, that's about it for now. Let me know if you guys get up this way. I'm going to do my best to catch Sun 'N Fun and look ya'll up! Till then,

Mike Denton, Pietenpol, Clarksville, Va., islanddocks@kerrlake.com
Reply from WW:
It's good to hear from you. When reading your e-mail, I thought about how long we've been hearing from you - four years to my memory, anyway.

The wheels were original equipment on J-3 Cubs. You can check Web sites that specialize in J-3 parts. I think Wag-Aero has J-3 parts. If not, Univair does.

Your carb ideas are good. I used to break in brand new engines on stock carbs just so they would start and run cleanly right off the bat. The engine's not finicky about carburetion, and as long as you don't tell the Chevrolet product it's sucking through a Ford item, it should work for you. Look for us at the Zenair booth at Sun 'N Fun. We'll see you then.

Subj: Corvair + Zenair 601
Date: 12/4/03

I ran into the link to your Web page and the Corvair engine installation - looks clean. I will be checking back to see how you optimize the installation and the performance.

Your article on carb ice is definitely food for thought. I've been mulling over the auto gas conversion to save money so I can afford to let my five kids learn to fly. But, the common sense in your article brought reality to that idea.

Reply from WW:
Thank you for the complimentary thoughts. Auto gas can definitely be used, but does require more attention to a number of issues. We have several pages of information on this in the Conversion Manual. A number of our customers fly on it and we've done a lot of testing. It works, but as I've said, requires more care in operation than AvGas.

Subj: Experimenter article
Date: 12/3/03

I just wanted to say I enjoyed the article in Experimenter last month. I guess there's still a few snake oil merchants out there, eh?

Reply from WW:
Yes, there are, and I'm sure there always will be no shortage of snake oil manufacturers. But, by and large, the good outweighs the bad, and as long as all the builders are educated, the market will take care of itself.

For those of you who don't subscribe to the premier magazine for homebuilders, I can't recommend highly enough visiting the EAA Web site and adding the publication to your membership.

Subj: Alabama Core Motor
Date: 12/2/03

I know that you're busy and this is probably one of the most frequently asked questions that you get, however, I am having real difficulty finding a core engine to get started. At this stage on the construction of my Zenith 601XL and given my current building pace, I don't have to resolve engine questions just yet, but I would like to go in that direction.

Originally, I was looking for a Lycoming core to rebuild because I have some limited experience with the engine type from a previous probject. I had also previously purchased your original conversion manual and, later, the upgraded version (Manual #5289) when I was still considering building a KR. It was only when I recently visited the Zenith Web site and noticed the reference to your Zenith project that I began considering the Corvair installation for this aircraft.

As a part of this process, I re-read your Conversion Manual in detail and have also reviewed the shop manual and some other publications. I also reviewed some of the parts sources (Clarks, etc.) to see what's available for the engine. To date, however, the only problem which has developed occurred when I began to search for a good core engine to continue the process. I've talked to a local Corvair group, looked through the Internet, and have searched through all of the junkyards within a reasonable distance. So far, the limited number of units that I've found (four in all) have been unacceptable because of damage.

Consequently, I hate to bother you with this, but do you have any suggestions that you could help me with ? Thanks.....

Mickey Pledger, mpled3559@aol.com
Reply from WW:
From our records, I see you're from Spanish Fort, Ala. I'll share with you the e-mail addresses of two builders who have running engines, one from north Alabama, and one from the Florida panhandle. Each of these guys found a good source of engines when they were looking for their own. Contact me again if these leads don't turn up a good motor. Numerous customers have written in saying that a cheap ad in a local newspaper quickly provided them with very inexpensive cores. One way or the other, we'll get you started on the engine part of your project.

Subj: Crank End Play
Date: 12/1/03

I just ordered your new video on engine assembly. The first one was really helpful, and I look forward to the new addition. I did it online, so there wasn't any allowance for the $5 discount for Corvair Flyer subscribers. No big deal because even at $25, it's a deal.

I did assemble my case, and the crank and cam rotate real nice, but I don't seem to have any endplay. I'm going to take the case apart to see if there are any burrs or problems, but do you have any suggestions on what to look for? Thanks,

John Krumrine, Zenair 601XL, State College, Penn., jqk4@verizon.net
Reply from WW:
Thank you again for your order. And thank you for understanding on the discount. We'd specified check or money order payments so we wouldn't have to give PayPal its percentage on top of the Flyer Subscribers Discount.

If your engine turns freely by hand, in all likelihood, it has sufficient end play. You really have to push the crank back and forth quite hard to measure it with a dial indicator. Even engines which have almost none on assembly end up with 5 or 6/1000ths after an hour's worth of operation.

Subj: Crank Shipping
Date: 11/30/03

We are building a Zenith 601 and plan to use a Corvair engine. Your Manual was very helpful in helping us decide which engine to use and what models we should use.

At the present time, we have a crank that is within specifications that we would like to exchange for one of yours. I made a box out of half-inch plywood to hold the crank for shipping. I guess my question is: How should we ship the crank to you?

We do not believe in reinventing the wheel and we are open to any suggestions that you might have concerning our project. Sincerely,

Robert & Shaun Rehmel, Manual 5602, Zenair 601, Richmond, Ind., Traveler601@earthlink.net
Reply from WW:
Thank you for your positive comments about the Manual. We're shooting to have our own 601 done by the end of January. We're going to make all the installation parts available in both drawings and finished parts, and additionally make videos just on the 601/Corvair combination. This should keep reinvention to a minimum.

When shipping a crank, I've found the best way to do it is to wrap it in old carpeting. All other types of padding fail to hold up. UPS commonly drops boxes 3 & 4 feet (we know people who work there). Carpet inside a box holds up to this fairly well. At this point, you can send your crank to our new hangar at 735A-3 Air Park Road, Edgewater, FL 32132.

Subj: Corvair Engines
Date: 11/29/03

I have been looking for Corvair engines and have found someone with two. I am probably going to buy both. Only one has a bellhousing and I know I need one and I'll either have some spare parts or maybe I can help someone else who is having trouble finding one. You mention in your Manual to only buy an engine you can turn over. These both have been stored inside for the past 15-20 years. Should I go ahead and buy them even if they won't turn over? I know. I know what the Manual says, but if these are what I can find, will I be way off base to buy them? Thanks in advance,

Marv, Marv@myrealbox.com
Reply from WW:
If the engines are in the $100 range, and they don't turn over, they may still be worth buying. If an engine won't turn over, pull out the plugs and look to see if one or two are completely rusty. This means the engine was filled with water at one time, and this isn't good. If they just look dirty and it won't turn over, chances are it's something less damaging.

Subj: Corvair Powered Midget Mustang
Date: 11/28/03

I would like your opinion on the Midget Mustang powered by Chevrolet. I like the fighter aircraft looks and am a classic airplane and car fan. Am I going the wrong direction with this? Thanks,

Reply from WW:
I've already built one motor mount for a Corvair engine to go on a Midget Mustang. A friend of mine at our airport has one that's 90% done. After studying the installation, it's a good match. There are several other guys working on the combination, but no one has flown it yet. Before starting one, make sure you'll fit. It's a small airplane. It should be understood that it's not an easy airplane to build. You don't have to be a genius, but it will take longer than other planes. You can search the past months' Q&A pages here at www.FlyCorvair.com with Ctrl + F for mustang and find several pictures and comments.

Subj: Oil Filter
Date: 11/27/03

Thanks for your Manual. It is a great study. The first video description mentions re-curving the distributor. How much detail does it go into, i.e., could I re-curve/re-build the distributor myself after viewing the video?

Also to other Canadians looking for Corvair blocks, there were tens of thousands of these cars made up here and they are around. After six months of on/off looking and calling, I found two side by side in a small northern town. Be patient. Thanks,

Martin Bima, STOL-Vair, Winnipeg, Canada, mbima@hydro.mb.ca
Reply from WW:
If you're a hard core do-it-yourselfer, there is a lot of good information in Corvair Engine Assembly Video I about how to rework the distributor. However, in almost every case, it's much easier to get the completely Remanufactured Distributor from us. If you study all the work and parts that I put into our Dual Ignition Distributors, you'll see that it is a very low profit margin item in our catalog. I keep it this way because I feel that everyone who is flying a Corvair should be using my Dual Ignition System. I don't want anyone on a tight budget to choose a less desirable ignition system for financial reasons.
Subj: Super FRED
Date: 11/26/03

I had a Son "William" October 4th and have been rather busy, but now I am thinking of Super FRED again.

The O-164 Corvair is considered by Eric Cluton as too heavy. However, his A-65 is 6" in front (mags are recessed into the FW) of the firewall and has an installed weight FWF minus the prop of 216 lbs. What is included in the 205 pounds - intake, and welded tube exhaust? I figure the mount at 6-8 lbs.

Matt Naiva, Wauwatosa, Wisc., steamlaunch@softhome.net
Reply from WW:
Congratulations. 205 is intake, no exhaust. Motor mount 5-7 pounds. My guess is that there'd be a lot of work in successfully reworking the FRED for Corvair power. But you're a clever guy, and I'm sure you could get it if you wanted it bad enough. Just for inspiration, consider that a Heath Parasol Model V has been successfully flown hundreds of hours on Corvair power.

Subj: Odd-fire imbalance
Date: 11/25/03

In the "Engine Beat" section of the December 2003 Kitplaness issue, John Larsen was critiquing the new Bombardier V220/V300T engines. I'm wondering about his statements regarding horizontally opposed engines. I'll paraphrase: 4-cylinder horizontally opposed engines are naturally balanced due to a power stroke every 180 degrees (in phase with the basic layout of the engine). Six-cylinder horizontally opposed engines, however, are NOT naturally balanced (he says) because the cylinders fire 1.5 times every 180 degrees, making them "odd-fire" engines (the power strokes are out of phase with the layout of the engine).

I was wondering if you could comment on Mr. Larsen's observations (possibly prompted by the Bombardier reps?) and speak to the types of mechanical and geometric balance required for a smooth running, reliable aircraft engine in your Q&A section. You mention on your Web site that Corvairs run like sewing machines. Does Mr. Larsen have a significant and valid point about horizontally opposed 6-cylinder engines? And if he does, how is this "odd-fire" phenomenon compensated for?

I know I said I'd shut up until I'd ordered your Manual and videos, but I thought that this article raised some interesting questions that might be worth responding to on the big stage of your Web site. Excuse me if this has been covered exhaustively already. If such is the case, I'd appreciate guidance to the section so I can learn something about it.

Terry Bendickson, La Crosse, Wisc., Terrben@aol.com
Reply from WW:
I know John Larsen and have met him personally. He's usually right about engine issues, but he's clearly mistaken in this case. He does not know what an even firing engine is. The Corvair motor is certainly an even firing motor. The actual definition is any motor that has equally spaced firing impulses. I don't know where his claim of broken 6-cylinder cranks comes from. The NTSB records show that quite the reverse is true. Six-cylinder engines have a phenomenon known as power lap, where the firing impulses overlap each other because they occur frequently enough. This significantly lowers the stress on the engine. Four stroke engines with five or fewer cylinders do not exhibit this characteristic and therefore are subject to internal stresses not seen in engines with six or more cylinders.

Subj: 601XL
Date: 11/24/03

I have come to your Web pages via a link on the Zenith 601 page. I have recently started my second Zenith project. The first a 701, and now the 601. I had been considering using a Jabiru 3300, but feel like Christmas has come reading all of your info. The ability to save substantial costs safely on the engine will allow for better avionics etc. I do have several questions for you, however. The cowling is always a concern on engines other than those the manufacturer uses. I see from Zenith's Web page you are building a 601 yourself using the Corvair engine. Will you keep me updated on how you are doing the cowling?

The second area of interest is the motor mount and exhaust system. Do you have these available or plans for them?

The final question is regarding turboing with the props you have. I live in Colorado on the front range and will be looking at flying at altitudes of 16,000 feet or more to clear the numerous fourteeners we have here in Colorado if I want to fly point to point without numerous diversions. I would also like the ability to get in and out of the mountain strips past 7 in the morning. I look forward to your reply and doing business with you in the future. Thanks,

Michael Armstrong, Zenith 601XL, #5207, EAA # 674318, ma80904@netscape.net
Reply from WW:
Over the next few months, I'll have all the 601 pieces available. Currently, I have the motor mount jig, and the cowling mold is not far behind. For guys operating on a budget, I intend to share drawings of some of the pieces.

My turbo engine is close to operating. All the plumbing, instrumentation, etc. is matched to my 601 airframe, so when the time comes, it will bolt right in. The Corvair is perfectly capable of mild turbo boosting. I think the 601XL, with its generous wing span and area, and sizable engine compartment, is a logical turbo airplane. 16,000 feet seems doable. But of course, the proof is in the test flying. We'll keep everyone posted at the www.FlyCorvair.com 601 Page.

Subj: Corvair/701
Date: 11/23/03

Came across your site this day and your information on the Corvair engine. I have always thought they would make an excellent aircraft engine. I am about to buy a kit for the Zenair 701. I noticed that the 601 has been mentioned. To your knowledge, could this engine be used in the 701? Have you had anyone inquire about such an installation? I would be most interested. I have been thinking about the Subaru EA81, but after my recent reading about weight, etc., the Corvair sounds as if it would be ideal. I am certain you are a very busy fellow, but if you could find the time to share this info with me, it would be most appreciated--Respectfully yours,

Terry O'Dacre, jto@monarch.net
Reply from WW:
The Zenair people tell me the 701 airframe was really designed around engines lighter than a Corvair or O-200. They asked me not to encourage people to install a Corvair in a 701. I'm sure somebody's going to fly the combination, and we have customers working on it. But out of respect for the family's wishes, I don't promote it. On the other hand, the 601 can easily handle engines in the Corvair's size category, and that's why we've chosen it for our own airplane.

Subj: FBI - Flyer Back Issues
Date: 11/22/03

I would like to purchase the back issues of your newsletter and the drawings for the new low profile Front Starter Brackets. I have Manual #5423. Please reply with costs and I will deposit the funds to your PayPal account. Thanks so much!

Al Manley, Longmont, Colo., amanley@attglobal.net
Reply from WW:
The back issues of The Flyer cost $10 and we cover the postage. The original Front Starter Bracket drawings are in Issue #4, and the back issue set is a booklet that includes Issues 1-4.

Subj: Engines
Date: 11/21/03

My name is Angelo Ferraro, and I'm a 601XL builder. Since the beginning, I was convinced that I needed at least 120HP for the plane to fly well, and this is more than the Subaru EA81 can deliver. Since I don't want to spend $15,000 for so called aviation engines, I elected to go for a Subaru EJ2.5 hoping that I could keep the weight down to 300 pounds... But I think it will be more like 350 pounds.

I can keep the power down by programming the computer, but it's the weight that I am concerned about. You are working on a turbo version of the Corvair - maybe that will do. I must confess that I am completely at a loss when it comes to motors. I don't even know what a spark plug is. So could you please, when you have some time, let me know what you think of all this. Best regards,

Angelo Ferraro, aferraro@videotron.ca
Reply from WW:
The 601 will fly very well on as little as 80hp. It has generous wing area and span in the XL model, and I have no doubt a standard 100hp Corvair will make it a fine flying airplane. We will probably fly our turbo Corvair 601 in the middle of next Spring. An engine like this would be 120hp with the standard size Corvair, 135hp or so on a large displacement engine. But I again emphasize that either one of these would be a turbo option, rather than a requirement. Understanding engines is fairly simple. Like anything else, you can learn about it by reading or asking people questions directly. If you have a local airport, this is a good place to start.

Subj: Starter/Generator
Date: 11/20/03

A thought occured to me as I looked at the pictures of the starter and alternator. If you used a generator/motor, could you start the engine using the proper pulley setup for charging? And does such a generator/motor exist? Or is an alternator such a superior device that one wouldn't want to mess around trying to save 20 pounds? Anyhow, I will order a Manual in the near future. I love Corvairs! We had six at one time. Thanks,

Kieran, kieranmays@tds.net
Reply from WW:
The only time in aviation where starter/generators were used was on early jets. These engines had extreme space requirements, and it was easy to mount a starter/generator straight in the nose of the engine. They haven't appeared on any piston engine aircraft that I know of. A starter/generator is always a loser in the weight department compared to a starter/alternator combination. Thank you for your interest. Write with any other questions you have.

Subj: Corvair/Vision
Date: 11/19/03

I'm Danny Johns. My question is whether a Corvair is going to be powerful enough to fly a full size Vision & not the Fold-A-Plane? Thanks for your reply.

Danny Johns, dfgpro@bellsouth.net
Reply from WW:
Fold-A-Plane is a building technique that's applicable to one-, two- and four-seat Vision aircraft. The Corvair motor is the design engine for the single-seater, and a good option for the two-seater with the EX extended wing. Fold-A-Plane tends to produce very light parts which require almost no filling or sanding. The Corvair is the most economical engine available to two-seat Vision builders, but it does require building a fairly light version of the airplane. The Fold-A-Plane technique makes this easy to achieve.

Subj: Avid
Date: 11/18/03

I met you at the Quickie fly-in in Kansas a couple of years ago. I sold my Q2 and now have an Avid MK IV with an NSI Subaru in it. My wife and I were thinking of an Avid Magnum or the equivalent Kitfox next, but don't like the complexity and weight of the water cooled engines. Seems like the Corvair is lighter than the Subaru? The six cylinder Jabiru is nice but $$. Seems like the Corvair is a natural for the Kitfox/Avid aircraft. I have to have a 25 lb. weight at the tailwheel now with the Subaru. Thanks,

Pierce Stewart, Avid MK IV, stewinttdrs@mail.telis.org
Reply from WW:
On a number of aircraft that were formerly Subaru powered, we've completed and flown direct drive Corvair installations. I can assure you that the standard Corvair would be significantly lighter. Options like 190cid Corvairs and the potential of using aluminum cylinders would further the Corvair's weight advantage. While it is true the core Subaru motor is light, by the time the reduction and the plumbing are done, it's frequently heavier than an O-235. As far as I understand, an Avid Magnum was originally aimed at engines in the 150-160hp range. It may fly well with less horsepower, but I'd check this out first. The standard late model Avid would certainly be a good match for the Corvair. If you'd like to see what one of our customers is doing with his Corvair installation in an Avid, check Dennis Smith's Web site, http://fp1.centurytel.net/aero-Smith/.

Subj: Corvair/CH601/Sonex questions
Date: 11/17/03

I'm new to the EA scene, so forgive me if you've answered similar questions before. I have read your FAQ by the way. First let me say that the Corvair sounds like a great step up from the VW. I am looking for an engine I can maintain myself at a resonable cost. Like you, I'd like to opt for a kit that will get me into the air relatively quickly (5-6 year projects are nice, but I want to go flying!). So it has come down to one of the 601 or 701 planes from Zenith, or the Sonex.

The 601s are cool, can accommodate the weight of the Corvair, and more importantly, you're already doing the bulk of the work! Not having flown in one, I have read they handle nicely. I really can't decide on which model 601 yet. What about putting a Corvair in the 701?

More importantly, I really like the Sonex design, and after speaking to a number of people, I have two questions for you:

1. Are you discouraging the Corvair out of respect for the designer? The weight of a 3300 Jab is pretty darn close to the installed Corvair...is the Corvair really such a bad match with the Sonex?

2. I have heard that there are weight and balance issues with the Sonex when one uses the recommended low-weight engines. Wouldn't this be partially alleviated with a slightly heavier (but more powerful) powerplant?

If you have had test flights in both planes (601 and Sonex), which one were you most impressed with in terms of flying qualities? Like I said, I think the Sonex styling wins hands down, but when one considers engine options and kit-confidence, Zenithair really starts to take the lead. Hope you can help me out. Thank you in advance for your time!

Rob, schaumr@hotmail.com
Reply from WW:
The Zenith people tell me that the 701 is really best off with engines lighter than the Corvair or O-200.

Many people are talking about installing a Corvair on the Sonex, and one has flown, but it is a tough match, and I promised John Monnett that I would not market the Corvair for his airframe. Can be done, but not easy, and I will not make a mount for it. The Corvair is about 35 pounds more than a 3300. This is significant. I dont really think the plane has real W&B issues, just different envelopes.

The Sonex is smaller. It is also a stronger plane. I build FWF parts for the 601, and it is an easier plane by far to put a Corvair on. They both fly well, but I suspect that the 601 will fly slower. They are both good companies, run by honest people.

Subj: 140 Distributor
Date: 11/16/03

Received the Manual (5797) last week. I have read it through a couple of times and it gets a little clearer each time. I have never attempted to remodel an engine before so this is going to be fun.

I do have a 1964 block and appropriate heads. However it does not have a fuel pump or distributor. I have found a distributor for a 140hp engine. My question is whether this can be rebuilt by you for my engine, or should I continue to look for a distributor off a 110hp engine? Thanks.

H. D. Yarbrough, Salmon, Idaho, yarbro@salmoninternet.com
Reply from WW:
Any late model distributor can be used for a core. I can rebuild any one into an aircraft grade dual points ignition. Fuel pumps are available fairly cheaply, and it's not worth searching out a core.

We're trying to keep a dozen Remanufactured Distributors in stock. Let us know whenever you're ready.

Subj: Flying Corvairs on a Davis
Date: 11/15/03

Thank you for all that you have done and are doing! A love of aviation and a thin wallet lead me to homebuilts. Airframes are fairly cheap, used instruments can get you by, but that darned powerplant. A spent engine with maybe 100 hours left on it is the least expensive at $5000-$6000? New engines-ha. Rotax looked like the answer, then the 912 got certified and doubled?tripled? in price.

So auto conversions! I love the Mazda rotary, but single rotor 80-100 horsepower are talked about but don't make it to the party. I had given up after a long path down VW motors lead to buy everything new for $6000, and then get 70 horsepower. So use the twin rotary at 170 horsepower on a different airplane. Won't even tell you how many sets of airplane plans are littering the house. (It is under twenty.) Then, heck, ultralight engines must be easier to come by! WRONG. Now I am looking at the two cylinder Corvair conversion by UltraVair that led me to your site and information.

Or heck - just build the Davis DA-2B with a Corvair powerplant (it is a set of plans I own). Thanks for keeping the dreams alive!

Neale Eyler, EAA #0526930, neyler@cessna.textron.com
Reply from WW:
Thank you very much for your e-mail. We saw our friend Jim Ballew this summer. He lives in Oklahoma and has about 500 hours on his Davis DA-2B.

Isn't it great how an affordable powerplant option fuels the imagination with so many possibilities of airplanes to build. And now, our old friend Fletcher Burns even has the 1/3 Corvair Ultravair motor. The Corvair has made a lot of people's aviation dreams a reality. If you want to get a look at a Corvair-powered Davis DA-2, check out Jim Ballew's Davis DA-2 at www.FlyCorvair.com.

Subj: Distributor Core
Date: 11/14/03

I am writing on behalf of Dan Palmer, Conversion Manual #5489 owner. By way of introduction, I am a retired Corvair repair person (I had my own shop), having built over 70 engines from the crank and cam up and have coached and supervised 12 to 15 people in building their own engines besides doing all the regular Corvair engine and mechanical work. Many, many years ago, I also took courses in wood aircraft construction and A&E Certification. The A&E should indicate that I am very much out of date.

I have read your Manual three times to digest your information and had some questions that Dan asked you and Richard Finch at the EAA meeting in Wisc. BTW, Richard has been a member of our Corvair club for some time. Dan has purchased a 1966 95 hp 9:1 engine from me and is in the process of cleaning, machining and accumulating parts for future assembly. On Page 18, you state that since the cam and ignition timing are replaced, there is no effective difference in a 95 hp 9:1 and 110 9:1 motor. My question is, which distributor should I give to Dan to send to you? In our shop, we had the same 1960 model Allen Tune Up distibutor machine and set up many distributors (we had specs and correct part #s for the many different distributors for different hp engines made by GM ) to correct parts houses' errors and mechanics installing the incorrect distributor. Do I give him a 95 or a 110 shaft? A 95 or 110 point cam? Which weights do you require? On Page 50 you state that you make adjustments to the advance weights, springs and stops. The shafts had many different size holes for the advance stops. Can I give him any, non 95 or 110, very good, very little worn shaft? The shaft posts were sometimes very badly worn, as were the holes in the advance weights. I still have most of these used items on hand.

Are there still AC44F plugs available? I will send you our 5th printing of our club publication booklet, The Care & Feeding of Your Corvair, for your perusal. Sincerly,

Sylvan Zuercher, Albuquerque, N.M.
Reply from WW:
Sounds like you have a real good background in Corvair motors. You should be a real asset to Dan's progress. As far as distributor cores go, I'll take any core you have which has the larger roll pin holding the gear on. I buy a steady supply of cores from Corvair automotive sources to supplement the cores people send in. Generally, about half the parts find their way into the wastebasket. I ask people to send us their cores so I have a steady supply of incoming material. I do them in batches and very rarely do I actually send the same distributor back. As you're aware, there are numerous different shafts, cams and counterweights. I have about six different combinations that will produce the desired results. Flight distributors are made out of a combination of parts from different distributors. AC44F plugs are available still as the resistor plug, R44F. Thank you in advance for the booklet.

Subj: TBO, Instrumentation
Date: 11/13/03

I am a prospective CH 601 HD builder. I have my plan set and will be building from plans, at least to start. Although I feel I am a long way from needing to make an engine decision, I have been looking around and discovered several builders on the Zenith board discussing the Corvair option.

Can you give me an estimate on the TBO on a freshly rebuilt Covair engine, or is there some way to tell when an engine needs re-build?

I'm also curious about engine instrumentation other than the tachometer - I found the info for that on the Web page. I am specifically interested in EGT and CHT probe locations and choices as well as normal operating ranges. Of course all of this may be answered in your Manual. Thanks in advance for any assistance,

Bob Lindley, travliman58@hotmail.com
Reply from WW:
An overhauled Corvair motor done to the specs in my Conversion Manual should easily go 1,000 hours. An engine such as this could be built for about $3,000, and when overhaul time arrives, the complete overhaul will likely cost less than $800. I have fairly good indications from flight testing that the engine may truly last 1,500 or more hours, but I'll wait till we get there to make it a statement of fact rather than a goal. When operating a Corvair engine, you'll know when it reaches TBO, just as you would if you were operating a certified engine. The engine will have above normal oil consumption, and have lower compression as measured by a differential compression tester. Additionally, if you're using oil analysis, you can spot trends in the engine's lifespan. We measure CHT with probes underneath the sparkplugs. The Corvair has one-piece cylinder heads, and generally one probe on each bank will give you a very good picture of CHT. Any EGT gauge style you like can be used on the engine. Each gauge manufacturer will have a recommendation for probe placement.

Subj: Corvair KR2
Date: 11/12/03

I was interested in puting a Corvair engine on a KR2. I was wondering how much they weighed and if there are any KRs with Corvairs on them. Thanks.

Matt, MSHUBAT@aol.com
Reply from WW:
Our Web site, at Flying Corvair powered planes at www.FlyCorvair.com, contains links to several flying KRs, including photos. The main Corvair FAQ page also contains data on weight. Most of our conversion parts work well on KRs. Most KR guys begin the conversion process with the purchase of one of our Conversion Manuals. It contains all the information you'll need.

Subj: Ragwing II and the Corvair
Date: 11/11/03

First I wanted to say I enjoyed your part of the Pietenpol presentation at Sun 'N Fun 2002. That is where I really got interested in the Corvair motor.

I am wondering what you think about the Corvair in Roger Mann's new Ragwing Wing Special II RW26. He is showing the Rotax 912 in the plane. I am interested in his RW26 because I am 6'4" tall and it is designed for a person of my size with the ability to bring along a second smaller person.

Thanks for all you do for the sport, and I enjoy your articles in the Experimenter. Thanks.

Chris Steckmann, Vidalia, Ga., EAA#0566212, talltwo@cybersouth.com
Reply from WW:
I've not personally seen a flying Ragwing aircraft, nor examined one structurally very closely. I'm not familiar with all the different models of his aircraft. One or two people who I know personally have said some of his earlier designs were very lightly built and not suitable for powerplants like a Corvair or O-200. I'm not sure if the RW26 is different from its brethren. Perhaps the appropriate thing for you to do is ask Roger Mann if the aircraft is appropriate for engines of the O-200's size and weight category. If it is, it can handle the Corvair.

Thank you for your positive comments.

Subj: Zenith Zodiac XL Support
Date: 11/10/03

I will be purchasing a Zenith Zodiac XL as soon as I sell my acreage, and I am at the planning/prepping/education stage of the project right now. I have been comparing many engine configurations for the Zodiac XL, and yours looked interesting. I am just a first time builder, so I would feel comfortable with more support, for example: the engine, engine mounts, reduction units, props, cowl, etc. supplied, so that I can basically bolt it on and go ... i.e., a firewall forward package or kit would be interesting. Knowing your engine can be supplied by you for $6,499, how much would it be for a firewall forward "package"? Any info would be greatly appreciated. Thanks! Regards,

Mark Mutschlechner, Allied.Seismic@pulsedatainc.com
Reply from WW:
In the next few months, we're working our way up to having every firewall forward piece for the 601. Even if we built your engine for you, test ran it, etc., I don't think the parts could possibly top $9,000, including the prop, cowling, mount, etc. Please follow along on our www.FlyCorvair.com 601 Web page and we'll have everything posted there. Keep in mind, however, the Corvair is a very simple engine (it has no reduction unit, it's direct drive), and you could save thousands of dollars on this estimate by building the motor yourself.

Subj: Turbo Parts List
Date: 11/9/03

In previous conversations and assorted posts you have mentioned that you will soon have the air turbo-Corvair finished, tested and unveiled. I am currently waiting on hold for this grand event. My engine has been disassembled and thoroughly cleaned, but I don't want to move forward until I hear what parts I should order that differ from those mentioned in your Manual, or what (if any) special machine work will be required. So the freshly-cleaned engine parts are sitting in a box collecting dust. While the grand unveiling may be a ways off yet, do you at least have a list of parts that I should order, or any special machining instructions that may be required. Also, are you considering writing a supplement to your Manual for these special conversions? I know, I for one, would gladly pay for such a supplement.

Bill Howerton, Bill@Howerton.com
Reply from WW:
I released three-quarters of a page of turbo information in the latest issue of The Corvair Flyer. Have you seen a copy of the newsletter? In short, the only internal difference you may wish to consider is utilizing a TB-10 camshaft. It's available from Clark's, and its part number is C-8801, or C-8801R if you wish to use a regrind. With that, you can go ahead and assemble your entire motor. All other changes are external. I still find the time to work on the turbo motor, but I don't see us flying it until spring. However, I'd like to have it running on the test stand long before then.

Subj: SA-7 and Corvair Engine
Date: 11/8/03

Thanks for your response. I reviewed your parts list. Looks good. I understand Corvair engines came in 164cid and 190cid sizes. Seems like the 190 would be a lot closer in torque to the O-200 recommended for the Skycoupe. I imagine they are a lot rarer than the 164. Can the 164 be converted to 190? What drawbacks might there be? And it seems to me that only low RPM engines like the A-65 ever develop their full at the propeller power potential - at around 2,300 RPM. How would the Corvair be with a reduction drive? Too heavy?

Mike Smith, Skycoupe, EAA Chapter 511, Shenandoah Valley, Va., turkeyridge@cat4.net
Reply from WW:
The 190cid motor is a modification of the standard 164cid, as explained in detail in The Corvair Conversion Manual. Primarily, the modification is machining it to adapt 94mm VW pistons and cylinders. It's approximately a $1,000 option on the rebuild when you consider it as a price increase over the standard 164cid rebuild.

Gary's Skycoupe has very good performance on a very mild 164cid conversion. It has a solid 100mph cruise on a 4.5 gallon per hour fuel burn at 2,600rpm. The Skycoupe plans show it to be approved for engines as small as 65hp. 100hp is not the minimum recommended engine. Most Skycoupes were built with 85s.

I'd respectfully differ with your opinion of engine thrust above 2,300rpm. An A-65 makes its rated 65 horses at 2,350 rpm; an O-200 makes its rated 100hp at 2,700. If you've flown the same airframe on these two different engines with properly matched propellers, you would clearly agree you could feel every single one of the O-200's extra 35hp. Prop efficiency at low rpm is largely a myth perpetuated by people who have done no direct testing with their own hands. Virtually all engines certified since WWII have been rated at 2,700rpm. If it weren't efficient to transfer power at these rpms, they would not have built these engines.

Although there may be some airframe that may benefit from having a reduction drive on a Corvair, the Skycoupe isn't it. It is an elegantly simple, solid airframe which is best matched by a simple, inexpensive, direct drive Corvair motor.

Subj: Corvair for Vari-eze or Taylorcraft
Date: 11/7/03

I have attended your demos at both Oshkosh and Lakeland, and I am very impressed with what you are doing with the Corvair engine. I was wondering if anyone had ever installed a Corvair engine in a Vari-eze or a clipped wing Taylorcraft. At present time I have a Great Lakes Bi-Plane which I have just about completed, and I am starting to consider what my next project will be. I am leaning toward the clipped wing T-Craft, but whatever I decide to build, I would like to have it powered by a Corvair. I would appreciate your comments and thoughts. Best regards,

Steve Davis, stephone@lexcominc.net
Reply from WW:
At least one Corvair powered VE flew. We have several people working on them, but it is not my favorite combination. The plane doesn't have a lot of versatility. I like planes which can land on grass.

Grace owns a Taylorcraft BC12D and looked into buying a clipped one last year. A Corvair would power either one.

Subj: RE: Zodiac 601 XL/Corvair
Date: 11/6/03

Thanks again for the quick response. My only thought of buying a turbo motor was for the nitrated crankshaft, but evidently Corvair engines are different from VWs. I built a EMPI "inch pincher" in the '70s and had to make sure the crankshaft was nitrated for the addition of turbo boost.

Well, let's get me started. I will locate the best engine I can, but before purchasing it, I will call or e-mail you to make sure it is suitable. I will also order your Manual, because I think I would be happier with the Corvair than the Revmaster 2100/turbo I have been looking for. My reasons are evident. Thanks again, and I will be back in touch.

Bob Geerhart, Zodiac 601XL, Carson City, Nev., thegeerharts@msn.com
Reply from WW:
While it's true that Corvair turbo and 140hp crankshafts were Tufftrited, I have a significant amount of flight testing on standard Corvair crankshafts, as well as cranks ground .010/.010, proving the standard Corvair crankshaft is suitably durable even for demanding flight applications.

Let me highly recommend you arm yourself with the Conversion Manual before you start shopping for egnines. The Manual and supplements including videos and The Corvair Flyer newsletter are available at The www.FlyCorvair.com Online Catalog. Occasionally you'll stumble across what appears to be a good buy, and it pays to have the information in the Manual at your disposal to save you from purchasing an unsuitable conversion candidate.

Subj: Zodiac 601 XL/Corvair
Date: 11/5/03

I read about your engine in the recent issue of Contact! magazine. And now while reviewing the Zenith Web site, I notice you are building a Zenith for your Corvair.

I live in Carson City, Nev., with an airport altitude of 4600ft. In the summer, density altitude can be quite high, and I will be flying into and out of other airports of equal and/or higher altitudes, so I think I would like to use a turbo on any engine I use. As the Zodiac will handle engine weights up to 265 lbs., I don't think that would be a problem if your engine can handle a turbo. The aircraft also has enough fuel storage to handle any length flight I would want to make. Any enlightenment you might give me would be appreciated. Thanks.

Bob Geerhart, Zodiac 601XL, Carson City, Nev., thegeerharts@msn.com
Reply from WW:
The flying turbo does not use any parts from the land turbo. Turbo car cores are expensive. The Conversion Manual covers all models of flying motors. Any good 1965-69 95 or 110hp will make a good flying turbo motor core. Our 601 will be turbocharged, but not right off the bat. The first motor we'll fly in it will be a straight-out-of the Conversion Manual, naturally aspirated, 100hp engine. After logging some time on this, I'll install a pre-tested turbo engine. I'll keep everybody posted on the developments of the turbo motor through the Corvair Flyer newsletter.

Subj: Corvair Flyer
Date: 11/4/03

I enjoyed your presentations at Oshkosh this year, and have been keeping up with your Web site and the discussion groups. I have obtained a very nice core engine with all the correct numbers. I may start the rebuild process this winter.

At Oshkosh I wrote a check for $30; for a year's subscription of your newsletter and copies of the past newsletters, but have not received anything, yet. BTW, I purchased manual #5169 at Oshkosh July 2002. Can you tell me of the status of the subscription and back-issues? Thanks,

Tom Hubbuch, Louisville, Ky., hthomw@yahoo.com
Reply from GE:
For being so patient and understanding, you'll be the first one outside The Corvair Authority Hangar to receive the Official Book of Corvair Flyer Back Issues.

William is still working on the Fall 2003 issue of The Corvair Flyer, and I'll get that in the mail as soon as it's complete. There's a lot of new stuff going on, so it will be a very full issue.

Subj: Teardown video?
Date: 11/3/03

I have the Corvair Engine Assembly Video II and have enjoyed it a couple of times already......... I'm looking forward to number III.

Have you given any thought to making a "teardown video" for a used motor in-tact, to pieces laying on the table, to pieces that need to be saved, to pieces for cores, etc.

Bob Moore, bobandlindamoore1@msn.com
Reply from WW:
Yes, we've given this more than thought. It's scripted, organized and ready to be shot. Our video genius, Merrill Isaacson, will be producing this one also. It's actually more difficult to film than any other video we've done because we need to find a core that's suitably difficult to disassemble so that we can show all the techniques for removing stuck nuts, etc. We're looking to have this video done by Christmas.

Subj: Awesome video
Date: 11/2/03

You folks are great!!! I have just returned home after eight days on the "Fire" line. I work up in Lake Arrowhead, California. I am in the water department up there. We have been running diesel fuel round the clock to standby generators to keep the pump stations running so they can have water as needed. The video is awesome, can't wait to get the rest of the series. Thanks,

Doug Blackburn, Yucaipa, Calif., twinboom@msn.com
Reply from WW:
Good to hear that you guys are winning the battle against the fires out there. The third in the Engine Assembly Video Series will be out shortly. We'll keep everybody posted. Besides the compliments, the most common comment about Video 2 was that it was short on funny outtakes. Believe it or not, we left them off out of a misguided attempt at the appearance of professionalism. But, the builders have spoken, and Merrill will go back to the traditional format of information first, outtakes at the end.

Subj: Aerobatic Corvair
Date: 11/1/03

I am very interested in the Corvair engine for its reliability and low cost. I am planning to design and build a Sport Aerobatic plane in the coming year. I note fuel injection for Corvair engines is not recommended. Can this engine be utilized with other carburetion and inverted oil for aerobatics in the 100 to 110 HP range??? While I have done some work with engines, I do not consider myself an engine person. This is not to indicate that I would not use this outstanding engine on other designs. Thank you for your assistance.

Benny J. Clark, texaswings@cox-internet.com
Reply from WW:
Although anything can be done with time, money and skill, I think that the Corvair is not for aerobatics. No one has ever broken a crank in a direct drive Corvair flight motor, but I am not sure if the crank is strong enough for real harsh aerobatics. You would spend a lot of time and money putting inverted systems on a Corvair, and in the end, very few people are looking for less than 200hp in single seat acro planes these days. I think your efforts would be better spent on other engines.

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