Corvair engine was a Franklin
Not sure where you've heard that. Perhaps you are thinking of the Tucker...
The Corvair engine was developed entirely in house by Chevrolet.
Ed Cole was in charge of coming up with the design and he used his experience from being a member of the team at Cadillac that developed the M41 Walker Bulldog tank at Cadillac's Cleveland facility. The M41 was powered by a Continental AOS-895-3 engine. This was a six-cylinder, air-cooled, four-stroke supercharged boxer engine, similar to contemporary aircraft engines.
Ed was also a pilot and flew his own Bonanza.
Robert P. Benzinger and engine designer Adelbert “Al” Kolbe were given the task of developing the engine under direction of Ed Cole's Corvair team. The engine was named the "Turbo-Air 6," and was first built in the Chevrolet Engineering department in December 1957.
Also, the Volkswagen engine was never based on an aircraft engine. It evolved from a Ferdinand Porsche design that started out as a two cylinder inline, similar to a motorcycle. When that design failed miserably, Porsche "borrowed" the flat four design of the Tatra engine and scaled it down to four cylinders.
Any resemblance to aircraft designs in 1936 was purely coincidental.
Yeah, I am an amateur automotive historian. I read a lot of books as a kid...
