[T Smith]

I don't see the valves having anything to do with it, they're closed when all this quenching is going on, the piston is coming to tdc to fire. The turbulence comes from the piston/head squishing together and causing the mixture to cross into the combustion chamber.

I'm mocking one up right now, 1.560 pin height flat tops w 2 valve reliefs, gonna cut it zero deck, .041 head gasket, 64cc heads. It'll be 10.6ish to 1 but with good quench and aluminum heads it should be fine on pump premium