63stl_comet
Well-known member
About how much should be milled of the head on a 200 out of a 67 mustang. I plan on 264h 110lc cam, dual out header, and dsII/msd 6 ignition? Not looking for a huge increase, just a bump and good sound!
67 200 questions
- Thread starter 63stl_comet
- Start date
Just to keep CR the same as the 67 200 has, you will have to determine the thickness of the new head gasket (compressed) compared to the old steel gasket (0.025) and mill that much off the head.
Example: If your new gasket is a Felpro from CI it will be 0.050 crush thickness (compressed); you will have to mill at least 0.025 off the head to maintain CR.
If your new gasket is a Corteco it will be 0.053 crush thickness; you will have to mill at least 0.028 off the head.
If you want to increase the CR from stock, there is a rule of thumb on how much to take off for X amount of compression increase. Maybe someone else can chime in on that. The best way is to measure the combustion chamber volume and calculate your CR, then go from there.
Hope this helps.
Example: If your new gasket is a Felpro from CI it will be 0.050 crush thickness (compressed); you will have to mill at least 0.025 off the head to maintain CR.
If your new gasket is a Corteco it will be 0.053 crush thickness; you will have to mill at least 0.028 off the head.
If you want to increase the CR from stock, there is a rule of thumb on how much to take off for X amount of compression increase. Maybe someone else can chime in on that. The best way is to measure the combustion chamber volume and calculate your CR, then go from there.
Hope this helps.
63stl_comet
Well-known member
I'm looking for a small bump in compression. Probably around 9.0:1 to make up for the drop that the can will cause. Probably need to get to around 53-51cc chambers, I think!