something to think about

crassius

Well-Known Member
Sep 30, 2012
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got new 40mm stroke motors

got 2 thick base gaskets so port map at TDC remains same (until it moves a bit & then # of degrees timing changes)

better or not to put 1 thick base gasket & add 1 thicker head gasket to give 1mm greater closure at both top and bottom

better or not to put a thin base gasket & add 2 thicker head gasket to give same port map at BDC
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
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You should try using just one stock base & head gasket first.

I've built several racing engines with 42mm cranks that didn't require any extra gaskets... (& this will give you higher compression). ;)
 

crassius

Well-Known Member
Sep 30, 2012
4,032
156
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USA
done that with the thick head gaskets back in the H2 motor days - if I still had a dyno, I'd try them all, but lacking good measurement of result, I'll just stick with what I have unless I see a need to experiment

got 2 of the new motors up on test bikes and won't offer them for sale until I see how they compare to each other, as that seems a good way to check factory tolerances - I believe they are both a bit better than the ones I had tho