How exactly do you do the drop valve method for finding TDC? I have been trying to get that stupid timing pin in for an hour already, and can't get it in. Since it isn't all that accurate anyway, I'll do the drop valve method. How do you tell?

 

Found this on another website. Hope it helps:

Originally posted by Joe G.
You can also find it by turning the #1 intake valve down five turns. Make sure you that you are exact at this. Fabricate a pointer from a piece of wire so that it indicates the crank pulley. Then bring the piston up until it touches. Mark the pulley where the pointer is. Loosen the intake valve until it is exactly where it was when you started. Roll the engine past the first touch point so the that piston is down again. Tighten the intake valve EXACTLY as much as before. Move the piston up until it touches. Mark the place the pointer indicates. Put the valve back like it was before you started. Halfway between the marks is exactly TDC. Check the timing pin. It should go in the hole at this point. Mark TDC on the crank pulley. So if you need to set it at TDC in the future position the crank to the mark and check the pin. If it goes in you are at TDC, if not roll it over one more time to the mark. You don't have to be this exact for a valve adjustment, but you do for timeing.

Good Luck, Kevin

 

I think there is a reason for calling it the Drop Valve method Like kd460 says, don't worry about being right on for a valve adjust- remember, the cam turns 1/2 crank speed and the heel of the cam is wide, so you have quite a bit of leeway there. Timing should be 'deadly' accurate though. Jim