Usually when riders talk about cams they refer to the lobe profile or the lift of the valve that they provide. Though, if you look at enough cams, you might begin to notice that cams with the same duration and lift can have different performance characteristics when installed in similar engines. A difference in the lobe separation angles (LSA) of the cams can explain the difference. LSA is the Lobe Separation Angle or the number of degrees between the intake and exhaust lobe centerlines. The LSA has a direct relationship to amount of overlap on a cam. Cams with identical duration and lift specifications can have very different LSAs. Generally speaking, a wide LSA will produce greater low end torque and a narrow separation angle will produce better top end power. For any given LSA, an engine will give similar torque curves and peak torque RPMs even with different overlaps. Intake Lobe Centerline is an imaginary line that passes through the camshaft rotation axis and the point of maximum lift of the intake lobe. Changing the lobe centerline without changing the duration can increase or decrease the point at which intake events take place during engines cycles. Increasing the intake lobe center line from 104 to 106 degrees is considered retarding. All events will take place later in the engine cycle. Retarding the cam causes the intake valve to open and close later. This will reduce cylinder pressure which reduce the low speed performance of the engine. Remember that advancing or retarding a cam effects both the intake and exhaust. Exhaust Lobe Centerline is an imaginary line that passes through the camshaft rotation axis and the point of maximum lift of the exhaust lobe. Changing the lobe centerline without changing the duration can increase or decrease the point at which exhaust events take place during engines cycles. Better get an expert to all these parameters prior ordering your set of cams in order to make sure what you are doing
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