The image to your left will give you some idea of the direction I'm now taking in my effort to find a more thermally efficient cylinder head.
What I have done is to move the existing exhaust: ports from their traditional location on the sides of the engine to a location beneath the engine.
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I've posted a bit more information on the rah GROUP but if you have questions they should probably be posted here.
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Picture of my smelter is posted to the right.
If you've not done any casting it is a handy skill, well worth your time to investigate.
-Bob Hoover