Finding TDC with engine in car

[astat1]

What is the best way to find TDC with engine in car. I have heard of piston stops but they are always mentioned with hand turning the engine. Do the harmonic balancers on 440's have a rubber bushing. I have a 428CJ and they have been known to slip making timing marks useless. I want to establish a corect timing but want the right starting point. Thanks

[aifilaw]

get a plastic straw, take out cylinder number 1.
rotate the engine by hand (by that I usually mean with a big wrench attached to the front crank bolt) and spin it around until it says TDC on cylinder 1. stick the straw in the spark plug hole on cylinder 1 and hand-move the engine back and forth a bit to see if that's true.

[Steve P.]

I agree with all except the BIG WRENCH.. I use a BIG RATCHET as I want it to ratchet when the motor kicks instead of busting my knuckles...   

[aifilaw]

I agree with all except the BIG WRENCH.. I use a BIG RATCHET as I want it to ratchet when the motor kicks instead of busting my knuckles...   

heh, I considered using the words "ratchet wrench", but was too lazy to type.... also be sure your ignition coil is disconnected, don't want it starting on you while you are doing such things.
Chryco can tell you a story about an engine that started and ran with the intake completely removed and sitting 10 inches away from the right bank of a motor on top of the left cylinder head... crazy stuff.

[John_Kunkel]

All factory Mopar dampers are subject to spinning the outer ring, I've had several of them come loose.

If you want to find exact TDC only a pistons stop will do, any bobbing indicators stuck in the plug hole will pick up directional and linger errors

BTW, a ratchet will only protect knuckles if it kicks in the direction of rotation, if it kicks back the ratchet will act just like a breaker bar.

[astat1]

I have seen piston stops but not sure how they work. They screw into the spark plug hole and then what? Do they actually hit the piston ? How do they avoid going into the piston?

[aifilaw]

its a stiff piece of plastic, basically they are a better form of a drink-straw that costs more.

[firefighter3931]

http://1970chargerregistry.com/70messageboard/viewtopic.php?t=1885