Finding TDC, degree wheel setup, intake centerline, and lobe separation verification.
Time: 20 min
Install a piston stop in the spark plug hole. Rotate the crank forward until it stops, mark the degree wheel. Rotate backward until it stops, mark again. True TDC is halfway between the marks.
Mount the dial indicator on the #1 intake lifter (or pushrod cup for OHC). Zero it at the base of the cam lobe.
Rotate the crank slowly through the intake event. Note the degree wheel reading at maximum lift on the dial indicator. That's the intake centerline.
Your measured intake centerline should match the cam card spec (e.g. 106° ATDC). If higher (later), the cam is retarded. If lower (earlier), the cam is advanced.
If the cam is off the card by more than 1–2°, install an offset key, offset bushing, or adjustable timing set to correct it. Re-degree after adjustment and verify final position after torquing the cam bolt.