The hot vapor engine. He talks alot about it in his biography. Seems like it would be fun to try and build one. His was turbocharged. The fuel air charge would get blown through a radiator built off of the exhaust. It would vaporize the fuel just before the engine sucked it in. He was able to make great power with very little fuel.
Hi javajoe
After reading my post it sounded as if i was contradicting you about the radiator, what I meant was no radiator for cooling engine he was using all the heat from engine to make power and the radiator you mention was used for other means.
Hope you didn't take it the wrong way

JL222