Originally Posted by
JesseT
It's very unconsiderate to make statements based on false assumptions. The difference in the compression rate is not made with the head gasket thickness. The ST170 gasket is on the order of 1.0mm and the other 2.0 gaskets, including RS, is on the order of 0.6mm thick. The thickness should be chosen so that the piston crown to cylinder head plane distance is optimum. Usually this is between 0.7-1.0mm depending on application. If you then end up with the wrong compression ratio, then you have an unsuitbale piston dish/dome volume.
Its right what you say about the pistons having a clearence to the head face but the thickness of the gasket does alter the compression ratio, the thicker gasket will create a larger squish area lowering the compression while the thinner gasket will reduce the squish area and increase the compression ratio. It wont make a huge difference but it does...FACT!
Thats why you can buy various thickness` of gaskets which makes up the "extra material" from having your head skimmed.
