|
Actually, since the head chamber has a slanted wall instead of a vertical one, the squish area is VERY SLIGHTLY increased when the head is shaved. Of course if you modify the combustion chamber to yield additional volume you will likely decrease that area even farther than it was stock!
If you happen to have dished pistons, of course, all this is blown into a cocked hat as the effective squish goes to zero in a hurry (unless they are custom pistons with squish areas incorporated...). Only use flattops myself but I thought it bore mentioning.
The only time you have to worry about piston contact vis-a-vis the bearing clearances, is on the exhaust stroke as the compression stroke is pushing down so hard on the piston crown (an "air-spring"). This is also present on the exhaust stroke but is lessened. I expect at lower RPM with a wild cam (lots of overlap) you may get a little "bounce" out of the piston. The contact is most likely when the heat of the engine is greatest (aluminum expands rather a lot) or if you are near engine failure anyway from lack of lube or poor cooling (lots of heat and suddenly expanded clearances).
Mike!
--
Mike!
|
