stk. long life cams have long opening closing ramps (cushion ramps) where valve is moved slowly off the seat and returned slowly to extend valvetrain/seat wear. these use up a lot of degrees when the valve is at low lift and low flow occuring. even on the 08 race int. duration measured at .050 is 235 degrees compared to 296 at 0 lift. means 61 degrees of duration the valve is .05 or less off the seat. not much flow happening here, a race cam profile can be much different with faster valve accleration/closing ramps allowing higher flow sooner and duration added to the profile at full lift holding the valve open longer there where maximium flow is occuring. cams can be same lift, same stated total duration, how quickly they achieve full lift, how long the valve is open in that area is the key to performance. it's not that it's only 4 degrees, more to do with where on the lift profile the added duration is most effective. could be much more than 4 there. all about the cam profile.
Last edited by gazx10; 03-18-2014 at 09:39 PM.