Cookwithvette

Ummm... what the title says. :)

I've tried looking in the spark plug hole but because of the angle I can't see inside.

Any tricks? :cheers:

Red86Z51

I had this same problem on a 78 Z/28

The only way to tell for sure is look at the orientation of the timing groove to the crank keyway, then compare with a known good balancer

zwede

You need an adjustable piston stop. It looks like a spark plug shell with a bolt through it (you can make your own this way). Turn the crank to 10 dgr BTDC, insert the piston stop into the #1 plug hole and turn the screw until it contacts the piston. Mark the screw so you know how far in it was. Now screw it out adn turn the crank past TDC. Find the position of the crank where the screw turns in to the same position as before as it hits the piston. Now true TDC is exactly in the middle between the 2 crank positions.

Example: You did 10 dgr BTDC and found that you had the same position of the screw at 4 dgr ATDC. True TDC is at 3dgr BTDC as indicated on balancer (i.e it has slipped 3 degrees).

mrvette

Cook , I have had it happen to me too, on an olde tyme Pontiac, what WAS a Pontiac....back when...and it's not all that easy IF the balancer if still more or less 'normal' looking,,....ie...not all out of line front/back looking, and therefore rather obvious looking....

I find pulling #1 plug, and turning engine by very quick starter pulses, OR by hand via vice grips on the flywheel/flex plate is the way to go...feel the high pressure, and then probe for TDC with a short coat hanger wire or such....
as flipping the crank back and forth...that gives a very accurate indication of the TDC mark...then see what the crank indicator says....and it better be really close, or the rubber harmonica balancer has slipped, and

when in balance, slipping is NOT an option....

GENE

Cookwithvette

Thank you very much guys. My motor has less than 5000 miles on it but something I suspect to be timing isn't adding up so I need to either confirm or rule out a balancer problem.

:cheers:

JB

When Lars tuned my car, he discovered that the balancer was slipped. We didn't have the TDC spark plug gadget handy, so he used a pencil wrapped with enough masking tape to wedge it in the spark plug hole. Worked like a charm. Good ol' Nordic ingenuity. :D

JB

cardo0

The piston stop method is the only way I can vogue for. But you need to be very careful and turn the motor over very slowly - as you can easily bend the piston stop tool or hole the top of the piston. Removing all the spark plugs will help a lot to turn the engine by hand at the crank snout. :yesnod: Instructions should come with the tool but if not you'll need to mark and measure both sides of TDC on your dampner for the piston stop locations. Now TDC is midway between the two marks but do this several times to verify - you'll know when you can repeat at same TDC. Just remember slowly and carefully. :thumbs:

RJR99SS

actually the easiest way is to just see if the crank keyway is in line with the timing groove.