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?

[Gint]

No it isn't more important to do it that way. Krusty's method works fine and a lot of people prefer it, but it's just a different way of getting the same job done.

As for the original question, chopsticks would work great. (IMG:style_emoticons/default/av-943.gif) Kidding Jeff...

Really, the distributor mark only gets you close. And depending on how much advance you've dialed in, that mark is going vary.

To find #1 TDC I've always done this: Put the rotor on the dizzy mark and then rock a raised wheel wheel with the transaxle in 5th to find either the TDC mark on the fan or the flywheel (I marked my flywheel so I can see it in the engine compartment). Then I go down and verify that the valves for #1 cylinder are both closed. To further verify I can then rock that same wheel to turn the motor and watch the valves open and close. From there you can just move along in the firing order for the remaining cylinders.

Now that I've done that once for the first time on my 914, I marked my flywheel so I can see it underneath the car also. This makes the entire valve adjustment process very easy and once I've set #1 I don't have to get back up from underneath the car.

I would think your idea would also be somewhat varied based on ignition timing, but then I'm no D-Jet expert so I don't know when exactly those points are closed. I'm sure an expert will pop up shortly...