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To verify my timing due to possible timing chain strech or other factors how can I find top dead center without taking the head off? Or can I?

Reason I ask is that I cannot get my timing mark to zero and I believe the harmonic balancer may not be installed correctly or the holes drilled in it are not perfect with regard to the timing mark.

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Remove the #1 spark plug (closest to the front of the engine). Stick a thin tool in the spark plug hole, like a long screwdriver that won't fall in. Using a wrench on your crankshaft bolt, slowly turn the engine until the tool tip quits rising and starts falling. Turn it back until it is at the very top of the apex.

With the Distributor cap off, you should see the rotor pointing towards plug wire #1 which is at roughly 10 o'clock (I think). Check the manual to be sure. Timing mark should be at 0, or very close.

With the valve cover off, both valves for the #1 cylinder should be closed. Follow the manual specs for setting your cam sprocket. Don't forget the wedge for the chain!
 

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zuber is close but you have to be on the compression stroke. Take #1 plug out then with place your finger over #1 plug hole. With a remote starter tap engine over untill your finger pushes out. This is very noticable over the exhaust stroke. tape engine up untill no air. This will get you real close, now use a piece of wire to feel when the piston is all the way up.
 

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The above suggestions will only give you an approximate T.D.C.
which you can use as a start. Take an old spark plug and break the insulator out of it.Take a tap and thread the inside of the spark plug you may have to drill it out. get a long bolt[that will thread into the plug]and a nut to lock the bolt.bring the
engine close to T.D.C. screw the plug in,screw in the bolt [with the nut on it] till the bolt stops against the piston[make sure you grind the edge of the bolt so you don't gouge the piston] lock it in place.mark the pully where your timing mark is pionting.turn the crankback around the other way till the piston comes up against the bolt[don't jamb it,take all the other plugs so it's easier to turn]slowly! mark the pully where the timing mark is pointing.Half way between those marks is T.D.C.
240 Al
 

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Wow. That would do it, alright. I could have mentioned that a special dial indicator could be used, but didn't see that that amount of precision was needed. It fairly easy to tell when the piston quits rising, and starts falling. But, you are right. Your way would give fairly accurate results.

I wonder. Isn't it slightly more dangerous to rotate your piston up against a fixed pointed object? Sure, be careful, but what happens if you slip and go too far? Or underestimate your strength? This is a good case for "close enough". Good tip though, Al.
 
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