Originally posted by Stazi:
The degree wheel needs a reference to - that what I'm getting at - there is non on the camSHAFT



That isn't how I learned to use a degree wheel. If you are proficient with one you learn very quickly how often the stcok reference marks are incorrect. Actually more so on aftermarket cams than stock ones.

First, the degree wheel is indexed by finding TDC on cylinder #1.

After that, there are at least two ways to do it. One is a certain amount of valve lift when the crank is in a certain position according to the degree wheel. Another is valve wide open with the lobe "straight up" at a certain crank position according to the degree wheel.

Of course, you need the cam makers specs to determine which method and what the values needed are.

On engines with multiple cams, each cam must be indexed after the first one is done.

And then the cam tuning begins. Advancing or retarding the cams moves the power band up or down the rpm range and indexing the intake cams differently to the exhaust cams alters valve overlap, which also moves the power band, but in two ways. It broadens or narrows the power band and / or moves the power band up or down the rpm scale. This is best done with a dyno run to compare the results.

Actually, there is a "poor mans dyno" method for optimizing the cam settings, but only if you are already very close and also if you are looking for broad band power with a good low end. Experiment with different cams settings while taking compression readings. You want the settings that give you the highest compression readings.


Jim Johnson 98 SVT 03 Escape Limited