I have finished my Thompson Engine. Plans and casting by Bob Herder. A relatively easy build. I did have a question earlier about rotation direction because of the tendency for the crankpin to come loose when running clockwise. I decided to reverse the direction and it seems have worked well. I used an o-ring in lieu of an oil groove or rings. Seems also to work well. There was no information given on timing, so I winged it. Set the exhaust valve to open shortly before BDC and to close at TDC. From there I set timing to fire at several degrees before TDC. Fired right up. Only problem seems to be getting fuel to the engine. Just a basic mixer with a check valve in the fuel line. I prime it by squirting a couple drops of fuel into the mixer and after a couple short bursts there is enough draft/suction for the mixer to take over on its own. Runs well after that. I am attaching some photos. Rick
