Even if you account for the con-rod's main bearing clearance, and distortion, the
length the rod expands, the piston pin's clearance, and distortion, much of that is
off-set by the expansion of the cylinder block.


Do expensive and / or modified engines use the approximately the same squish clearance?

If they all use .5mm or greater squish clearance, why don't they use a hemispherical
(homogenous) combustion chamber. At some point, any gains in reliability by using a
stratified combustion chamber is lost when the squish clearance is too great.

Why lower the compression (by increasing squish clearance) for nitro content, if you
exceed the ability of the stratified combustion chamber, to keep the piston crown
cool?


Bill Mazz