Cam timing (adjustable timing chain)

What generic effect does adjusting the cam timing have on engine performance? Advancing a cam using an adjustable timing chain does what? I'm pretty sure my cam was ground to be set straight up but I'm just wondering.

Dan, in general terms, advancing a cam usually gives more low end power, and retarding a cam will give more higher rpm power. This is usually at the expense of some power loss at the opposite end of the scale.


cheers
Ed N.

Theoretically what ED said..But in real world testing retarding the cam has more often then not lost power all over the RPM range while advancig has generally gained power throughout.

It depends on the motor. If you lack head flow for the provided cubic inches and/or have a large stroke then retarding the motor will take the unneeded low end torque in substitution with high end torque and horsepower.

If you have a small block motor advancing the cam does the opposite. It gains low end and in most situations power is increased in the upper RPM ranges due to less drafting off of other cylinders aka less "reversion."

With forced inducted motors it is best to leave the cam straight up and leave it up to ignition timing to make up whatever difference you need.

I agree

Whats been said above is generally right. We have experimented ALOT on the engines we do (mostly motorcycles) and advancing the cam(s) always brings more power, low, mid and high in most cases. Retarding cams will kill low and mid range for a miniscule gain up high in these motors. My drag racer friends say that on big block type engines retard can work though.

I have yet to have the opportunity to play with cam timing on a forced induction set up. Would love to hear opinions/experiences from someone that has done it on an SC or otherwise.