How to determine EXACTLY where TDC is?, Valve adjustment advice needed Options

[JeffBowlsby]

Eyeballing alignment of the rotor to the tick mark on the dizzy body seems so imprecise...for adjusting valves. Is there a method of locating TDC for each cyl PRECISELY?

1. I thought about making some kind of rotor replacement device with a pointer that could extend down close to the tick mark, but thats only good for cyl 1. All cylinders needed.

2. I thought about making a special trigger point plug adapter with three long wires, and attaching it to me DVM on the buzzer setting. When the trigger points would make contact, then that would indicate...? I am not sure that the trigger points make contact at TDC, I think it is at some different point in the cycle.

Any time proven methods?

[VaccaRabite]

Toms right. Due to the cam layout of our cars (the same cam lobe works both sides of the motor) if the opposing lifter is in at all, you know that the one you are looking at is ready to be adjusted. All you need to know is the pattern - which can be found here all over the place after a brief search.

But, if you really much know TDC, put a straw down the spark plug hole, and watch it, As the piston comes up it will move the straw. This is easiest to do with two people. One to turn the motor, one to feel the straw. Just remember that the motor comes to the top of its travel 2X per cycle, and only one of them is TDC. You are at TDC when the piston is at the top AND both valves are closed.

Zach