Rebuilding a b230f with a b23f head. I have flat top pistons on the way how do I figure the compression radio? The hight of the new poison is the same as the old just no dish.

 

displacement should be same (pi*diameter^2/4*stroke)

total volume is the sum of the displacement and static volume. you can probably estimate the static volume as a bunch of small thin cylinders using the same formula

the compression will be the ratio of total/static

 

They are over sized to 96.6mm there is a ridge at the cylinder top so I am going to bore the cylinders