I had my 67 289 rebuilt. I am trying to set the timing for the first start. I have the pointer lined up with the TDC mark on the harmonic balancer but I do not think the engine is at TDC. I was hand cranking with the valve cover off and when I got to the TDC mark the valve for #1 did not open or close. I do not know exactly which it should do but nothing happened with #1.

My question is does the harmonic balancer only fit on the crank one way so the timing marks are always lined up correct? Could the rebuilder have put the harmonic balancer on incorrectly so the timing marks are not properly aligned?

If the balancer is not on correctly, what should I do?

Thanks,
Stephen

 

The balancer is weighted, so it's keyed to fit only one way. Your car should have the mark on the LH side and the crank pulley held on by 3 bolts.

 

well lets see

1)make sure you rotate the engine the right direction same as if it were running.

2) both valves should stay closed at the piston heads towards TDC as this is the compression stroke
3) Both valves should stay closed right after TDC as this is the power stroke forcing the piston down the bore (if a valve opens right after TDC this would vent the pressure needed to force the piston down)
4) as piston reaches very bottom and returns up the exhaust valve should open the instant that piston starts to head back up the bore. (exhaust stroke)
5) as the piston reaches the top again and heads back down the intake valve should open (intake stroke)
6) as the piston reaches the very bottom go back to #2

-Gun

 

Also;
The best time to assure TDC is during the build with the head off. At TDC the piston is at the high point, so you can make sure the timing pointer is positioned at the zero mark of the balancer. There is some play here.

 

So there is only one way for harmonic balancer to fit on the crank, I should trust that when I align the timing marks at TDC the engine is actually at TDC?

 

There is only one way for it to fit on the crank. You can still be 180 off with the timing marks on top dead center. If you put it on TDC and both valves are closed on #1 cylinder then you are on top dead. If the exhaust valve is open then you are 180 degrees off. Rotate the crank one full turn, both valves should be closed and then you will be on TDC.

 

Sorry for the ignorance, but how do you tell when the valve is closed? Is the valve spring compressed when the valve is open?

 

by watching the rocker arm that presses down on the valve. have someone rotate the engine over for you by hand (or pull the coil wire and have some one crank it over in small burst....but rotating it over by hand is ideal using a large ratchet on the main bolt in the center of the damper wheel) as the engine rotates you'll see the rocker arm press down then come back up. wiggle the rocker arm as it comes back up when you can wiggle it there is no load on the valve spring and the valve is closed.

-Gun