Advancing cam 2 degrees

the full, layman's response to the question is this:

You have 2 "timings" that are discussed in automotives - ignition timing and cam timing...................both are in regards to their timing in relation to the piston (usually at TDC)


While ign timing is relative to WHEN the spark plug fires, valve timing is relative to WHEN the valves start to open.

When you advance the cam, you open the intake valve sooner and close the exhaust valve sooner.

If you were to take a cold cranking compression measurement now, advanced the cam 2*, and took another compression test, you'll see pressure INCREASED.

This will be true for your dynamic compression as well.............

Its true that advancing the cam brings power in sooner while retarding it bring power in later.................

If you dyno the car, you'll make a torque "curve".......................advancing the cam or retarding the cam will not change the curve, rather it will move the curve forward or back on the scale; but NOT change the curve the cam creates.

When playing with valve timing, please ensure p/v (piston to valve) clearance.............

Valve timing is not infanite.............and you can measure this with cranking compression................ie. 0* may make 135 psi, +2* may make 148 psi, +4* may make 155 psi..............................but then when you goto +6* you may see a decrease to 142 psi......................this is the point of deminishing return.

Now you know that this cam will not benefit you @ anymore than +4* and we would assume the same going the other way (retarding). But, this gives us an 8* sweet spot to "play with".

When you advance, please note you'll most likely need to change spark advance for best benefit..............