William Wynne

Ask The Authority! January-June 2003 Daily Question & Answers

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

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 t