Author Topic: Thompson Engine  (Read 1223 times)

Offline rick41

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Thompson Engine
« on: October 04, 2020, 05:41:06 PM »
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

Offline propforward

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Re: Thompson Engine
« Reply #1 on: October 04, 2020, 11:50:14 PM »
Fantastic - really nice engine!

Forging ahead regardless.