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As with everything, there's history behind it. Read through Langford's adventures and see what happened and why it happened. Great information. And you'll learn the story of the "5th Bearing".

Azalea Aviation is another provider of Corvair equipment, and Bill even designed an airplane to go around it.

azaleaaviation.com

http://azaleaaviation.com/

~Chris

**Papa Foxtrot** · 10-24-2017, 07:55 PM

Originally posted by Battson View Post

Suddenly I don't feel as confident about Corvair's engines....

The crank issues are mainly due to the original GM cranks being cast. They appear to give few issues in low performance applications(i.e. Pietenpol Aircamper). If you read Mark's site, he freely admits to pushing the envelope. Dan Weseman(https://flywithspa.com/) sells a new billet 4340 crank; which, along with his 5th bearing, should make this a non-issue.

**Papa Foxtrot** · 10-24-2017, 08:08 PM

Originally posted by Chris In Milwaukee View Post

Azalea Aviation is another provider of Corvair equipment, and Bill even designed an airplane to go around it.

Full disclosure - I've never done business with or even met Bill Clapp. By all accounts, he's a very nice individual. However, as a long time member of the KR and Corvaircraft mailing lists - I've read a lot of history of Bill and his companies. There's been some very dissatisfied customers over the years - of course, the internet tends to magnify these conflicts.

I'm not saying to avoid his business, but do your due diligence.

**davzLSA** · 10-26-2017, 09:19 PM

Since William Wynne and several others have developed the 5th bearing the broken crank in the corvair has not been a problem and this has been so for years. There are hundreds of planes flying corvair engines for thousands of hours with no problems. What I like about dealing with William Wynne and Sport performance aviation is these are the people that have tested and developed the corvair for 25 years and are the ones I trust to know more about corvairs than anyone else. William Wynne has been in the business of developing, testing and flying corvair engines for 25 years. The products and support that William Wynne and SPA provide are without equal when it come to parts and most of all education on how to build them, maintain them and fly them. I recommend that if you are considering a corvair dont let anecdotal information influence your decision but get real facts from proven sources. https://flywithspa.com/ https://flycorvair.net/ or https://flycorvair.com

**Papa Foxtrot** · 10-27-2017, 10:24 AM

Since Mark was flying with one of William's first 5th bearings(I believe it was no. 2, IIRC) when he broke his third GM crank, I'm pretty sure that didn't fix it. Not sure about "anecdotal information", but I've known Mark Langford for 20 years. The first time I visited his house to look at his KR project, he was still planning to use a Type IV VW. In the immortal words of Elmer Keith, "Hell, I was there" for most of this saga. I know more of this story than I'm willing to tell in an open internet forum. There are a lot of "personalities" involved. Be very careful.

There are no new GM Corvair crankshafts. I would not fly behind a cast iron, 50 year old Corvair crankshaft of unknown history, period. While Dan's billet crank isn't cheap, it's not optional, IMO. Carefully examine the motives of anyone that tells you otherwise.

**davzLSA** · 10-29-2017, 01:02 AM

HI Papa Foxtrot, William doesn't sell his 5th bearing any longer but he steers people toward Dan Wessmans 5th bearing and as far as I know there has not been any broken old GM cranks that is been processed by Dans shop. Im not 100% sure about that but you can check with Dan. I have had dealings with him and I believe him to be a truthful man. But the cranks do get a very through going over before they are put into flight engines and there are a lot of them flying everyday with no problems and they are cheap and plentiful. One of the main problems with Corvairs is that some people thought since it is a car engine that they can treat it like a car engine and take it to a car shop to do their machine work and other tasks and what they get back are parts good enough for a car. As you know a flight engine demands a much higher standard of precision. The advantage of dealing with people that build Corvair flight engines for a living and have researched them for 25 years is that they know what works in a flight engine and what doesn't. I know you probably think Im a salesman for SPA or Flycorvair but im not. I have built a Corvair flight engine and I have met Dan Wessman and William Wynne and the thing that impressed me the most about them was the way they do business which is highly ethical and the mass of information they have on the Corviar and of course all the flight proven research they have done. I have looked and I have not found and company or any other entity that has been around as long at William Wynnes company. The philosophy they have in regard to the engines and builder is very genuine All I would tell anyone is to get all the information them selves and there are several good references are posted here.

**Papa Foxtrot** · 10-29-2017, 10:05 PM

Dan Weseman's a good guy. Best thing William ever did for his business was outsource the order desk and fulfillment to Dan. As good as Dan is - magnafluxing, stress relieving and nitriding can't change the base metallurgy of a 50 year old cast iron crankshaft. One problem with experimental aviation is that it takes a long time to determine that you have a problem. Parts get sold, engines assembled and then they sit in a corner waiting for the airframe. A very large percentage of projects never reach completion. Mark had 456 hours on his 5th bearing motor before the crank broke. How long does it take most builders to fly 400 hours even if they do manage to get to first flight? I think Dan's doing everything possible to make those old crankshafts safe for flight. It's just not enough for me personally.

Interesting that VW Type I aircraft conversions had the same problems until the builders started using 4340 cranks from the performance suppliers instead of the factory cranks.

If your personal risk tolerance includes building a flight motor with an old crankshaft that was originally designed to be used in an inexpensive economy car, then best of luck to you. BTW, Dan's last name is Weseman, not Wessman.

**davzLSA** · 10-29-2017, 11:52 PM

Hi Papa Foxtrot, I totally agree with your post and here is a description of what Dan puts the crank through. https://flycorvair.net/2015/08/23/so...00-crankshaft/ As far as using the old crank that is a personal choice that anyone building one of these engines must make for them selves. Thanks for the spelling correction on Dans last name. It's usually mispronounced as well. Since Dan and William are working together now the parts do come much quicker. I built my engine during the transition and I noticed a real difference when Dan's company took over distribution. They are very responsive and any answer to a question is just a phone call away. I dont believe anyone could have made it any easier to build a Corvair flight engine. I believe even if one used Dan's billet crank when building a Corvair flight engine the price would still be less expensive than rebuilding an o-200. One of the really cool things about dealing with Dan and William is of course the Corvair colleges where you can take your engine parts and William or Dan will personally supervise you assembling the engine. I assembled my engine from the instructions and took it down to Jacksonville Fl and ran it on Williams test stand during one of the finishing schools they put on. It was a great experience and I learned a lot while running my engine and helping others run their engine. https://flycorvair.net/?s=finishing+school I wish you good luck in all your flying endeavors Papa Foxtrot.

**William Wynne** · 11-02-2017, 09:58 PM

A friend sent a link to this thread an suggested I read it. While I understand that much of the conversation is light hearted banter, and isn't serious guidance, I want to offer a few words of correction for people who may later read this thread and repeat some of the errors in it.

In several places, mr Papa Foxtrot, who feels he knows the Corvair Crankshaft story states that the stock corvair crankshaft is "Cast Iron". This is patently false. 100% of all 1.8 million corvair cranks made by GM were forged steel. If you don't even know the material the cranks are made of, perhaps you don't know the story as well as you imply.

If you look at my website and search Bob Barrows name, it will spit out a lot of pictures of Bob, my wife and myself. You can see Bobs comments on Corvairs filled by the EAA photo crew that produced a documentary about one of the Corvair Colleges we gave at Barnwell SC in 2013. Bob offered his opinion that the engine as we teach people to build it is a viable option. You don't have to choose the engine, but I assume that people building Bobs design respect his opinions.

I understand why many people don't want to use their full name on the internet, but I'm really reluctant to form options on things based on comments made by people with strong opinions who don't use their actual name. If that guy is just casually looking over the shoulder of one person with a negative experience, you are not going to get a very accurate picture. I trust that I'm better friends with Mark Langford that the guy making the comments, and you can verify this by looking at pictures of both Mark and I staying at each others houses on the web. Mark langford clearly states that he isn't a typical builder, and he built his equipment his way, not mine. for that reason, his experience isn't representative of my builders. You can get a much better idea of how the engine works when it is built in my recommended configuration by going on you tube and looking at all the SPA/Panther Videos of the engine flying aerobatics. Notably, Dan Weseman has more than 1,000 hours of Corvair time, about 75% on forged steel stock cranks and 25% on his USA billet crank, he flies a lot harder than Mark Langford, and Dan has broken 0 cranks. So maybe configuration matters.

The engine isn't for everybody. The people we serve best are those willing to put the effort in to take advantage of the educational and hands on support we offer. Today, a lot of people just want to buy something, and thats fine. But if you are a traditional homebuilder, and you got into aviation to see how much you can learn, not how little, the Corvair may be the engine for you.

William Wynne

**Chris In Milwaukee** · 11-02-2017, 10:02 PM

Thanks for checking in, William. Glad to get your input on this popular engine from a fellow with immense experience with it. Appreciate your guidance!

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