12/21/2024 08:28:17 PM

PONTIAC POWER RULES ! ! !

Head Flow Ratio Calculator



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Superflow determined a long time ago that the maximum ideal value for head flow ratio is 146 cfm/sq.in.
This number is for an 'ideal' frictionless orifice with no dump or expansion losses.
A good ratio would be 133 cfm/sq.in. for a single intake valve.
137 cfm/sq.in. is good for a 2 intake valve setup.
If your flow ratio is smaller than the 133 cfm/sq.in. then you are losing some power.
Talk to your head porter and see if he can get some better numbers.

Head Flow Ratio Calculator
Number of Cylinders:
RPM at HP Peak:
RPM at Torque Peak:
Bore:
Stroke:
Rod Length:
Head CFM (@ 28"):
Intake CSA:

Input Stroke, Bore, Please