73GreenMachine
Well-known member
My motor is coming together. At the moment, I have just dropped in the engine and torqued up the head when the questin crosses my mind: what is the compression ratio of the motor. Ford Six Performance manual says that the combustion chamber volume is 60cc for a US 200. Looking at the heads though, there appears to be a different combustion chamber design. Its more kidney shaped than a wedge like the US head. I'm wondering wether the Aussie head has a different combustion chamber volume because of this. My head is a 72 cast low compression head for a 200ci pre crossflow. The head had about 30 thou taken off of it and bigger valves put in. It had been faced before. The block also got faced and I'm running flat top pistons and standard ACL vrs kit head gasket. I was originally aiming for 9.5:1 compression but I think its closer to 9:1. I'm now wishing I had cc'd the combustion chamber.
