This calculator determines the "Static Area Flow" value of the combination of head air flow and valve lift for camshaft type, lobe use and profile choices. The calculator interpolates the head flow data between each listed valve lift and matches it with the calculated valve lift at each crankshaft position for the chosen cam specs. You can pick a predefined head and/or cam or enter your own values. The resultant Area Flow listed is "Static" because engine RPM and piston speed at crank position is ignored and instead the head port vacuum is assumed to be a constant 28inH2O (common flow bench standard). The Avg AF is the "Average Area Flow". It is calculated by dividing the "Area Under Curve" of the Area Flow values between TDC and BDC inclusive by that rotation amount.
The data displayed will change if a different Lobe use (intake or exhaust valve), "Ctr line" or "Rocker" is selected for the same head and cam.
NOTE: Air flow below 0.050" valve lift is ignored.