Thread: Finding TDC

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I've grown tired of searching for earlier posts where this has been before, and it appears the only way to find things is by starting a thread so I can search with "Thread Started By"

If you're not sure of your timing marks you can verify the pointer to dampener Zero mark in a non-invasive way with some light oil, clear tubing and an old spark plug.
1) Break up an old spark plug and hot glue a length of clear plastic tubing to it (make it airtight).
2) Remove all the spark plugs.
3) Stick your thumb over the #1 cylinder spark plug hole. Rotate the engine using a breaker bar on the dampener bolt until you feel air pressure on your thumb for the compression stroke.
4) Screw in the spark plug with plastic tubing attached and insert the other end of the tube into a jar of light oil. Continue rotating the engine. Bubbles will appear until the piston reaches the top of its travel. When it starts down on the next stroke, the bubbles will stop and oil will begin traveling up the tube. Stop at a convenient point (don't go too far) and mark the liquid level in the tube and also mark the crank pulley at your pointer.
5) Rotate the engine backwards and watch the oil recede into the jar. Continue rotating. As the piston continues past TDC and downward it will again suck oil into the tube. Rotate the engine till the oil again reaches the mark on the tube. Stop at that point and mark the dampener where it lines up with the pointer. You should now have two marks on the crankshaft pulley, and the exact midpoint between these two marks lined up with the pointer is TDC. If you want you can iterate to smaller and smaller separation on the marks by re-marking your tube at lower levels and repeating the process a few times.

If you find that your Zero mark is off you should check your harmonic balancer for de-lamination which can allow the outer ring to move relative to the hub.

I wrote this article for the Crankshaft Coalition wiki. It has since been edited by 6 other fellows who are pretty sharp, so it's really good info in my humble opinion.....
http://www.crankshaftcoalition.com/w...op_dead_center
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It's better that "really good" Tech - it's fantastic. I printed it, still reference it, and have pointed others to it long before I knew it had your paw prints all over it. In the footer the following appears:

"This page has been accessed 43,368 times."

I'd say you guys hit a home run with this article. It's absolute technical knowledge imparted in a way most anyone with a 9th grade education can read and comprehend. Thanks for sharing your work with us!

As always, my regards and respect!
Glenn

Wow, that's quite a response Glenn. Thank you very much.

Good information Roger and Tech. Thanks for posting.

Hey that's the CAT'S Meow !!!