Can someone please discuss the concept of overlap and lobe seperation in a cam? What impact does this have on an N/A motor vs. a supercharged motor? I really know nothing about cams and would like more info on the subject.
Overlap allows a well designed combination to have the exhaust pulse start pulling a fresh charge of air/fuel into the combustion chamber. Low to no overlap is good for vacuum levels in the intake. High overlap tends to lower intake vaccum levels.
Lobe seperation along with lobe ramp design determines how much overlap there will be in a cam.