Thread: Quick TDC question...

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My buddy and I are in disagreement about finding true TDC center on my 454 engine.

The problem: My new timing cover has no timing tab, so I purchased a bolt on tab and we are in discussion as to how most accurately set it...

The question: If I line up the marks on my timing chain sprockets, will that put the #1 piston at TDC? I could then line up the tab to the mark on the balancer and drop the distributor at the same time...? The sprockets are installed at default locations, no advance.

yes we're rookies

set a dial indicater on the deck at # 1 cylender. turn the crankshaft till the piston goes down say .040 then turn it the other way .040 . in the middle of the 2 readings is absolute TDC. it will work with all depths. hell 1 inch down is ok.

My heads are already on,so I can't really set a dial indicator on the deck. The engine is basically buttoned up and almost ready to go back into the car now. I guess I could use a piston stop tool too. I figured looking at the timing chain would be the most accurate (with the heads installed).

Piston stop Gus. Quite a few posts in this forum walks you through it to be dead on with TDC.

thx, I just went thru the piston stop drill on my buddy's mustang. His new balancer had no timing marks on it. I was hoping I could use the marks on my timing sprockets to bypass the routine.

Just so we are on the same page, when you line up the marks on the timing chain sprockets to install the chain, they have no relation to the whereabouts of TDC on the engine...?

Darn close, but will not be 100% accurate. It will always be just a smidgen off for ignition timing accuracy.

I just had a thought. My pan is not permanently on yet. I could rotate the engine in the stand and peer at the piston from underneath. What do you guys think? Accurate enough?

Crankshaft still rotates as the piston "dwells" at both top and bottom of the stroke. Please go with the piston stop method.

ok thx again

Loosen the nuts on your #1 Cylinder rocker arms before you run the piston up against the stop. Sometimes a valve can hit it as you crank the engine around. Also, remove all the other spark plugs so the engine will turn over easily and you can feel the piston kiss the stop.