piston top dead center

[fiat218]

how do u know if it on the top
i am aware that u look trru the plug hole, but how do u know if it firing top or exhaust
thnks

[131]

Put your thumb over the plug hole as you're turning the crank, you'll feel the compression as the piston comes up.

[mdrburchette]

I put the end of a screwdriver into the plug hole, have someone turn the engine slowly and you can see it at top dead center when the screwdriver is furthest out of the hole.

[rlux4]

Also, a technique I use to find true TDC is to put a wooden dowel in the spark plug hole and watch for it to reach the top of the stroke. You'll see that it stays at the top as the engine rotates through a few degrees before it starts down. 1/2 way between reaching the top and starting down is top, dead center.
Ron

Edit; Denise, I saw your post as I was posting mine. Nothing wrong with a screwdriver, but hey, I'm a carpenter.

[fiat218]

thanks , great tips

BTW DENISE the gold carbs will be at my house by sat or monday can't wait

[maytag]

Maybe I misread the question? I think his question was not how to tell if the piston was at the top of the stroke, but rather how to tell which stroke it is at the top of: compression or exhaust?

Was that the question, 218? Sometimes I can't tell.

If that's the question, take a look at the valves. pop a valve-cover and you can watch 'em open & close. There may be an easier way, but this is how I do it.

[DocGraphics]

2 ways I know of, like 131 said put your finger in the hole while turning the engine over w/ a wrench & when it gets blown out then it is coming up on the compression stroke.
The other way is if the distributor hasn't been moved look at which cylinder the rotor is pointing to & thats the one on compression, then rotate the motor till pointing at the right cylinder.
The TDC mark on the crank will line up when cylinder 1 & 4 are at their respective TDC (180 out with 2 & 3)