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Static CR doesn't mean anything. Your effective or "Dynamic" CR only begins to start compression at . 004" or . 006" lift. Static CR is just compression if your valves were closed the whole travel of the piston, calculated with the chamber volume. Pistons are never exactly at bdc or tdc when the valves are opening or closing. This is why cam manufacturers give you a recommended compression ratio for their cams. They are doing the math for you to get your effective CR in a range best suited for the cam. You can tweak this a little if you know what fuel you want to run and do the math yourself.
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