Piston stop

[Mercury Mike]

What's a good one to use, and how exactly do they work? I haven't ever used one before.

 

[rickwrench]

The homemade one is cheapest. Smash the guts out of an old spark plug and jam the right size bolt through the remains. About two inches should protrude. Glob some epoxy on it to keep the bolt from moving, smooth off any sharp any edges that might nick the piston, and make sure the threads are clean.
You use it to find TDC.
Screw the stop snugly into the spark plug hole of the #1 cylinder. By hand, slowly, turn the engine over until it hits the stop. Mark the balancer at the pointer. Turn the engine slowly back over the other way untill it hits the stop again, and mark the balancer again. Halfway between the two marks is exactly TDC.
Rick(wrench)

 

[addo]

Metric thread; M18×1.5mm

You could always just buy a bolt.

For safety's sake, remove the battery from the car, and put it aside. Much nicer than forgetting for a moment, what you're doing.

Cheers, Adam.

 

[cfmustang]

I bought one from Summit Racing (easy since I work about 20 miles from one of their showrooms). They have a few different kinds, I bought this one from Comp Cams.

 

[Mercury Mike]

Anyone have a picture of a homemade stop? I just wanna make sure I do it right, and have all the information before I jump into the project. Made the mistake of not having it all too many times! Thanks.

 

[Redfalken]

Here's one I made. I was able to pound a nut down into the opening from the top and it should be held in tight enough that it won't push it back up. I filed the top flat and put a washer/nut there just to help keep the bolt from being pushed one way or the other. Also there is room around the bolt shank that comes out of the bottom and I drilled a small hole just above the bevel that seats in the engine block so air can exit the cylinder as I turn it over.

Now...I haven't used this yet so I may need to cut another bolt to get the right amount sticking down into the cylinder but that wouldn't take long to do.

 

[Mercury Mike]

I made one today! Woo! Thanks for your help guys.