Cam Help

[Super73]

Typically you want to choose valve events first based on what or how you want the motor to run, then build for max dynamic compression based on the fuel you will run. The fuel is the limit before predetonation becomes an issue. There is more too it than that like head chamber shape, head material, quench ect. But a generic rule of thumb is 8.5 DCR is about the max you can run on pump gas.

With that being said, I was trying to help you work that backwards based on our camshafts intake valve closing point but you only provided .050" numbers not .006" numbers. You are not starting to build compression until the valve is fully closed. Since the intake valve is closing after bottom dead center, the later it closes the less DCR you have.

You are almost always going to make more TQ and HP with more dynamic compression. You mined as well max it out at the 8.5 DCR.

The cam you were looking at going with, can you provide a link to the MFG's page or give us the .006" duration numbers? Then we can work your 8.5-1 DCR backwards and figure out what SCR would be required. Then we can look at the heads you are using, gasket thickness, bore, stroke and figure out what you will need in a piston to achieve your final DCR.