This is a NEW (new old stock) PAW (Progress Aero Works) diesel model airplane engine. It is called a PAW 80 because its displacement is .80cc. This is the same as .049ci. This is an absolute jewel of an engine. Once the compression and needle valve settings are found it is very easy to stop and start. The engine was run for about 45 minutes total in this session, edited down to about 17 minutes. It used about 1.5 ounces of fuel to run for 45 minutes and it's now pretty well broken in. The counter-piston is still too tight but reducing speed to idle and loosening the compression screws allows the CP to "pop" free. It will probably become more free with more run time. This little diesel runs like a swiss watch.