Tim, here are some 50ish Diesels to check out per our conversation.

Below is an excerpt from Feb of 09
Diesel Friends, I put another hour on the Fox .50 today, it takes that long to burn a little over half of a 16OZ tank. At the end of the 60 minute run it is turning the Graupner 12x7 at 9,650, this time I used a stock EZ Just carb and stock Fox muffler. I can tell its improved in another way, it now holds compression like an ABC engine, no leak off when slow flipping.