We have all heard too big head kills performance.
While agree with etreme amount to be true.

Wondering hiw many here have gone to bigger head and lost performance? If so how much bigger.

If like to compare yorr heads to formula/
Int require flow. ci x rpm/9140 exh ,75 to ,80(call it .75) x int, flow. Seems lots of factors would influence real world requirements of air needed

I have been told by cpl dyno guys most all engine work out to 2.1 to 2.2 x head flow, Take it for what it is worth. Real world comparison be nice here too.

While on subject of head flow. therory on alky motors needing bigger ports to accomidate extra fuel taking more available area for oxygen. Thoughts?

Just the formula. Hopefully Chad will chime in with real world flow information.

555 ci motor with Dart pro1 335CC heads ran 5.7s all day

582 with Brodix BBX3 380cc heads. 5.7s real good air 5.6s

Same car - same MPH.