The late Smokey Yunick (1923-2001) was one of the greatest automotive engineering minds the world has known. Smokey was also notorious for cheating and being so full of BS in NASCAR that stories about him are legendary. One of Smokey’s most legendary engineering feats (and rule violations) was building a 7/8 scale Chevelle and racing it in a NASCAR race.
It’s no surprise then, that one of his most significant accomplishments has people who doubt it’s very existence. The adiabatic engine project by Smokey was an engine design that promised unreal feats from a carbureted gasoline engine. The claims of a 150 horsepower, 50 miles-per-gallon, two cylinder engine are enough to set the tin-foil hat brigade chattering about a possible government-big oil conspiracy to keep Smokey’s invention out of the hands of Joe Consumer.
After a few Google searches and a few days looking around to see what I could find, I didn’t come up with much beyond theory and anecdotal evidence. I did notice a few patents, with this one being most likely the one that sets everyone’s brain gears a-whirring. Here’s the only diagram of anything remotely related to an adiabatic engine:
It seems this guy probably did more research than just about anyone, but most of the links are broken now, and the site’s a bit hard to read due to a language barrier.
Nearly every Smokey Yunick historian remembers the adiabatic Fiero, but no one can find evidence of it’s existence or an actual guide to the technology it possessed.
After reading a few days about Smokey, it seems to me that he would have enjoyed the controversy.