Max horsepower with EQ heads?
Maybe this will help, from Muscle Motors...... .257 x no. of cylinders x flow @ 28"
example-- .257 x 8 x 410 = 843 hp.
There are similar formulae out there, the variable is the aggressiveness of the valvetrain action & it's control. Most of these are based on a fairly(but not extremely) mech.
flat tappet camshaft profile. Not max velocity .904 dia. based with high ratio rockers, not mushroom tappets, not rollers. The output factor goes up with these as long as
the springs/pushrods/etc. are up to actuating & controlling this high rate. Similarly, the velocity in a head is going to limit flow as IQ52 said, the more efficient a port is,
the higher this
can be. But the viscosity of the fluid(air&fuel) will eventually develop sufficient friction that, for lack of a better "visual", the boundary layers "swell" up &
start "closing" the effective flow area of the port. Bigger engines demand more and the port velocity for a given RPM is automatically higher, so if the port CA can't handle
6K, it does little good to equip the engine with a 7K combo..........................
