This is a statement for the record as to which mass produced engine converted to diesel was the most powerfull. It was American and was the Cox and later K&B Conquest .15 with one of our conversions. Larry Renger the point man for Cox sent me 2 Conquests an R/C and Free flight version and an 8X4 Cox gray Propeller. We made a head and ran the prop on both engines and got 18,200 Rpm a great number. I called and told them the results and I got this response. "That's great, it as good as glow." Many years later I came across an article in the foreign notes by Peter Chinn. It was a review on the Conquest glow 10% and on a cox gray 8X4 the Rpm was 16,500 Rpm, what do you know! More recently there was an endurance free flight/R/C event to honer the a famous pioneer and the engine was the Conquest with our head and a then available Kraft Radio an all American system.

P.S. the three most powerfull engines are still American the Nelson, Jett and the fox.

Bob Davis
Davis Diesel