SBM Edelbrock/Speedmaster Head Data

273 said

This is above my paygrade also, what I meant by seems somewhat independent, if optimal valve job/area is kind of standardized, seems to me it's independent to the port configuration then.

Not saying I'm right, just an observation.

Click to expand...

I think I follow the logic. Not pretending I'm right either. It's my understanding that cid, rpm and # of cylinders determine cfm demand and therefore the ideal valve size. The valve size (somewhat) fixes the throat size. Since cfm is already determined, this fixes the ideal port size because of target port velocities. There are equations for all of this.

The real world of bore sizes, combustion chamber shapes, head bolts, water jackets, pushrod locations, hood clearance height and on an on force the valve and port sizes and configurations to be less than ideal, especially in a older street motor.

Some of the newer HiPo stuff and any good race motor - the whole intake system is totally interdependent.