The process is not difficult but was new to me. The first step is to confirm TDC on your engine. I used a piston stop and recorded the degree wheel reading when the piston hit the stop going forward and backward. Top Dead Center (TDC) is then the midpoint between those two measurements.
It was at this point, I realized what has been contributing to my problems with the Mustang. The stock harmonic balancer ring shifted which threw off the TDC marks. When I thought I had 12 degrees advance, I really only had 4 or 5. If I had noticed this before, I might have been able to get better vaccum reading or set the idle mixture screws better on the carburetor.
I then confirmed how the cam was degreed using the intake centerline method. With this method, you rotate the engine until you reach .050" lift on the intake and mark the degree. You then rotate the engine past peak lift and stop when back down to .050" lift on the back side of the intake lobe. You then take these two degree measurements, add them together, and then divide by two to determine intake centerline. My cam should be installed with an intake centerline of 106 degrees and that was the exact figure I reached.
Since I had the degree wheel connected, I decided I'd go ahead and check all the specifications on the cam card to the actual cam grind I received. It was strangely a fun process to check the numbers and see how they matched against the card. I found the following:
Intake Lift: 3.02 @ lobe (.483 @ valve) - this is a higher than the card
Intake Duration: 212 @ .050 lift - exact
Exhaust Lift: 3.06 @ lobe (4.896 @ valve) - this is higher then the card
Exhaust Duration: 218 @ .0505 lift - exact
I also checked the exact point at which each valve opens (using .006 as the criteria). I found the intake opens and closes a degree late. I found the exhaust opens and closes 3 degrees earlier. There is not much to do about this but is nice to get a little more familiar with the process of checking a cam.
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