8/30/2014 08:30:38 PM

Camshaft Calculator

For a more accurate calculation try Larry Meaux's Pipe Max.
His program is excellent and will provide a lot of info.
Pipe Max

Camshaft Lobe Center / Duration Calculator
Intake Opens BTDC (ATDC is -) : (in degrees)
Intake Closes ABDC : (in degrees)
Exhaust Opens BBDC : (in degrees)
Exhaust Closes ATDC (BTDC is -) : (in degrees)

Input Intake Opening,Close and Exhaust Opening/Close Please


The amount of time, expressed in crankshaft degrees, that describes the window of time between the the Intake Cam's opening point BTDC and the Exhaust Cam's closing point ATDC. Increasing the degrees of overlap tends to move the powerband up the RPM band. Increasing the overlap can increase peak power, but only if the exhaust system is properly designed to scavenge the cylinder. Decreasing the overlap tends to boost lower rpm performance.

Lobe Centers

This is the angle between the intake and exhaust camshaft lobe peaks described in camshaft degrees. Generally speaking the majority of cams will fall between 98 and 120 degrees. This angle dictates two important events: the valve overlap around TDC, and intake or exhaust valve closure delay there is in the relevant stroke (inlet/exhaust). Tightening the lobe center angle produces more overlap around TDC and wider angles mean less overlap.

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