[73LeMans]

So I fired up the motor the other day for the first time, and I tried to time it, but the line on the balancer is bouncing all over the place. I'm not sure why. Any ideas? Let me tell you what I believe to be true, and then you can tell me what I'm overlooking?

• The balancer is a Fluiddamper. It slips on tight, and the key ways are not loose.

• The HEI distributor has been recurved by Larry Rowe and has new bronze distributor gear. The coil is about 3 years old. The cap is about the same. MSD does all of the real work in the dist and there is no module.

• Plug wires are 8mm Taylors in great condition. 3 years old. (less than 500 miles)

• The timing chain is old in age, (6 years) but can’t have but 500 miles on it. It’s a Comp Cam double roller. Been on and off the motor 5 times or so. Installed can straight up.

•The cam is a brand new Comp Cam solid roller. The engine fired right up when we initially started it so I don't think it’s the cam due to lobe/gear/wear, but I never checked the end play on the cam and I also don't have anything spacing out the cam where the fuel pump eccentric used to be. You think this could be it? I never ran the fuel pump eccentric with the old hydraulic Comp cam and never had this problem.

Someone I had spoken to claims the flexplate might be out of round and causing crank vibrations up to the cam… I don't buy it, but I haven’t seen everything…possible? The flexplate is a stock Pontiac one with the 3 holes for the converter slightly enlarged to 7/16ths. (up maybe a 16th from the original hole) Drilled it myself. Could be out of round, but wouldn’t that cause an erratic idle more than it would cause spark timing to be flaky?

I think I covered everything it could be…any thoughts?

Oh yeah…the timing gun is a relatively new Sears dial back gun. Works fine on others cars.

If you think of something, let me know. I’ll be checking back when I get the chance.


Thanks in advance.

Who needs nice and pretty, when you can have mean and nasty? 73 LeMans: 12.5 in the 1/4 on its way to 10.90's!