25 years after warning people, cast pistons still show up in planes.
William Wynne
Builders,
More than 25 years ago, long before the internet, I wrote my first Corvair manual, and printed it on a then modern dot matrix printer. In that manual, and in every one since, I have told builders not to use cast pistons in aircraft motors. I have never built a single flight engine using them, and this is not a new position. Yet, after all these years, people still put them in engines, and if they later resell that engine, it is frequently said to be ” Built to Wynne’s Manual”, a statement we would generously call “misleading”, the polite word for “dangerous lie.”
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The two reasons people put cast pistons in motors are they are cheap, and they are advised to do so by a “Local Expert”. If you want to read a direct story of this, follow this link:“Local Expert” convinces builder to use cast pistons. When you are done, please get a look at this story, and the links in it before buying anything: Junk you should not buy..
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Many people believe in “Let the Buyer beware” and I sort of do, but not in aviation where the penalties are pretty stiff. Truth be told, I have another angle also: When junk like cast pistons fails in a Corvair, none of the people who look at it say “That was not compliant with how William teaches people to build engines” In almost every case, nearly every witness will only learn Corvairs=Bad. Most people are not very sophisticated in how they develop opinions these days, and they bring that to aviation, complete with a ‘facts don’t matter’ attitude.
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Many people know that a very large effort was put out by a law firm to blame me for a non-fatal accident several years ago. This is an extreme example of how people who don’t want to listen to my experience will not take personal responsibility for that decision. The facts: I didn’t sell the person a single part. I sent him 11 emails saying his plane was un-airworthy, including one the day before his 45 second flight. He refused, in email, to buy a timing light saying the previous owner must have set the timing. He was a 60 hour powered Parachute pilot with no transition training. He brought a passenger on the first flight. His Dynon recorded the CHT at 628F in 45 seconds into the take off. He used low grade car gas for the flight and failed to conduct a two minute test. All of this made no difference, they still wanted to get it into Federal Court in Arkansas. So If I sound heavy handed on this and not very libertarian, it is because after something goes wrong, the guy who made the choice almost never stands up and publicly says “This was my fault.”
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Above, these came out of a motor which a guy was actually building to fly. The motor was based on a Short stroke early Corvair, with a weak early crank, no 5th bearing, and plenty of other things I have told people to never do. If you look above, an irony: they guy used billet connecting rods with Chinese cast pistons. If you look at the underside of the piston there is a mark that is a G outside and N. It is a Chinese brand. This engine was sold to a builder, who fortunately treated it as a core motor. It came to Corvair College #42 as parts. But someone who owned a manual of mine actually put this together to fly. If it was flown, it would have almost certainly broken, and caused a crash. How would you like it if a wealthy law firm claimed this was your fault? Welcome to our legal system. As I have said many times, I am a devout believer in the ideals of our nation, but the execution of those ideals can fall pretty short at times.
