Inliners International Forums General Discussion Hi Performance Help to Compression and Piston issue

to lower the compression ratio further, you now have a wonderful opportunity to optimize the combustion chamber by unshrouding the valves by removing material from the "tub". I would not hog it out wider, just deeper and open up the area around the valves so the mixture has somewhere to go once it passes the valve.
You could probably also dig the piston dish deeper some, without risking anything, considering your mild build and intended use. I would try to see if you can mirror the combustion chamber shape on the piston dish if possible, so the dish isn't wider than the chamber tub unnecessarily.

One of the advantages of what you now have is the zero deck, it alone allows for higher compression ratio, everything else being equal.