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O-320 convert to high compression pistons... worth it?

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Patric_L

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Hello there...
Is somebody on this platform with experience in the power difference before and after converting to high compression pistons?

My engine is a midtime (500h since complete OH) O-320 mounted on a Pitts S-1S. Engine runs fine so far but at least one cylinder is starting to have low readings on leak-test etc. This sure comes from corrosion on the cylinder walls and the leak test results slowly go down over the years. The engine has a history of sitting for quite some time. Lifters, Cam etc. have been replaced but for saving some costs we decided to go on with the cylinders as they were as long as compressions are ok and they don't start to leak oil etc. So far the engine is running fine, reliable and is not making metal.

I slowly start to worry at least a bit about the cylinder walls and maybe some new or overhauled cylinders are maybe coming in the future.
With an 160hp O-320 you are not at the high power end with an S-1 and more horses are always better. So I thought about converting to high compression pistons by the time the cylinders are off for a change. As I don't want to build a handgranade I prefer some "mild" increase like going with 9,5:1 compression. But is this even noticable? My thoughts are to stay with my current prop as I'm not unhappy with the performance in higher RPMs but with a bit more HP the slow speed performance should increase since the engine should rotate the prop a bit faster.

Am I totally wrong on this? Anybody with first hand experience? Is 9.5:1 enough to feel a difference?
I know that with more compression/hp you produce more heat, reduce TBO etc. I allready have that in mind :)

Regards
Patric
 

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