I am preparing a new head and measured the combustion chambers at 54cc. My last head has 55.2cc chambers and gave me very low compression.
I am curious how small have others gone with the combustion chamber. I want to surface the head and that will make the chamber smaller. Anyone running 53cc chambers?

 

I've measured a few, they all seem to come in right at 53-54cc

you have to watch piston-head clearance once you start milling the head a ton. I've run mine milled upwards of 0.030". Never measured the chambers at that point.

 

Won't that increase your CR a little as well? What CR are you after sideways?

 

I have 9:1 pistons with the large chamber volumes it is probably around 8.5:1. I've done compression checks and it runs 155 per cylinder.

9.5 would be nice.

 

...and your still pulling down like 550 rwhp?
nice

 

If I remember my calculations right decking the head 0.015 will get you almost a point

 

A little heads up,

0.010 inches milled removes 1.5cc chamber volume.

This is theoretical using the bore size and also confirmed with measuring the chamber.

 

The s2000 chamber is only 86mm not 87mm

 

Yes, I rounded from 1.48cc