What do the cam specs mean?
Duration: This is the basis for how your motor will perform in the RPM range. A higher duration cam will make power higher in the powerband, and lower duration will make power lower in the RPM range. Duration refers to how long the valve is opened in relation to Crankshaft position. If a cam is listed as a 220 Duration, that means the valve is opened for 220 degrees of crankshaft rotation. Lift: This spec is stating how far the valve is opened. measured in thousandths of inches (.xxx). More isnt always better, but you want to make sure that you have enough lift to compliment the duration, or you will have an airflow restriction. Lobe Separation: This refers to the spacing between the Intake Lobe, and the Exhaust lobe on the camshaft. This value is expressed in the in degrees on the camshaft, NOT the crankshaft. Every company that sells camshafts will include what each cam is designed for. Naturally Aspirated cams will normally have a lobe separation between 110 and 113, Nitrous Cams ar
