Optimum Intake Runner Calculation By Bowling

Engine volumetric efficiency and power can be increased considerably by taking advantage of the natural dynamic effects which occur during the intake filling cycle. The kinetic energy of the resonant pulses can be harnessed to fill the engine cylinder at volumetric efficiencies up to 130%. When the intake valve closes, a pressure pulse "bounces" back of the intake tract and then in again towards the valve, and if timed properly, extra air can be "shoved" in. To use this pulse, the intake port must be the correct length, and only occurs during a narrow RPM band. The following calculation yields an simple, empirically-derived range of RPMs for a given intake runner length (mean). Second, third, and fourth order harmonics are provided.

Program Inputs:

Intake Runner Length in Inches:

Press this button to submit a computation:

To reset the form input:

Bruce Bowling
Bowling Superior