Top Dead Center

[Mike E.]

Where do I go to find a gauge to measure when my piston is top dead center? Exactly what is that called? Approximate price?
Thanks,
Mike Ernst

[William C.]

Re: Top Dead Center

Mike, there are several ways to do it, but the easiest is to use a "positive stop" method, make a tool by removing the insides (porcelin) of a spark plug, and secure a length of rod in the Sparkplug shell about 1 inch longer than the end of the spark plug would have been originally (Round the bottom of the protrusion). Take out all the plugs, and insert the "tool" in number 1 sparkplug hole, preferably with the piston well off TDC. rotate the crank by hand until it stops, mark that with a line on the damper. reverse the rotation until it stops again. mark that spot on the damper. TDC is exactly midway between the two.

[John H.]

Re: Top Dead Center

Most speed shops (and Summit, Jeg's, etc.) sell "piston stop" tools for about ten bucks that accommodate both sizes of spark plug threads, with a threaded adjustable center stop rod.

[Mike M.]

Re: Top Dead Center

Rev; do as clup says with stop inserted in #1 plug hole but bolt a degree wheel on the harm. balancer, take measurement in degrees when stop stops the #1 piston and recard that measurement in degrees, then reverse rotatoion of crank till stop stops piston again, record that measurement. TDC is half way between your two measurements in degrees. this method more accurate than marking the balancer. mike

[Clem Z.]

make sure that the piston stop you use has a hole

to relieve the compression as you turn the engine over.GM parts sells one part# 12364087

[Bob Simard]

I'm surprised that Dennis and Mike

have not told someone that "top dead center" is a reference to the other parties forehead.

[Dennis C.]

Re: I'm surprised that Dennis and Mike

Mikie must'a had to go to bed early tonight.