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Lift, duration and even spring pressure is NOT what kills cams on the street. It is how aggressive the lobe is. IE, how fast it opens and closes the valve. A VERY aggressive ramp speed on a lobe will murder a valvetrain in short order on the street. Keep the lifter ON the cam and you will be fine. Ultra fast "closing ramps" where the cam basically falls out from under the lifter will munch parts.

Monte



But that is directly related to spring pressures. There is also valve seats and guides and lifters to worry about. And spring pressure will have an effect.

I can have two cams, with the same lift and duration and also the same seat and over the top pressure.....lets say 300 and 800. With lobe profiles I can make one ultra reliable and the other beat valvetrain parts out as fast as you can change them.

I design some BIG stuff for several Drag Week cars. Lifts approaching 1" and seat pressures of 375. They survive Drag Week just fine. Its all about the ramps

Monte

So the big question has been for me, and ive asked this on Yellowbullet with no sucess, is, how do you see or judge an agressive lobe by looking at cam specs? I know its easy to just ask a lobe designer, but I want to know myself.