I was searching the forum, but did surprisingly find nothing.
In the mid-90s I changed my camshaft on my '68 350! Stupidly I forgot to remove the bolt securing the harmonic balancer while pulling it from the crankshaft. So it came apart, but I could push it back on and this worked for years. Of course the timing mark was not in the same place, but I knew it and it was no problem.
3 years ago I got my engine rebuilt by a German US-car service, but after it, it never run really smooth. They tried a lot of things, mainly adjusting the valves and the carb. Nothing helped, so I decided to do it myself.
I always thought, that it might be an ignition problem. And after a check with a timing light, I found out, that the original mark was a hit. But this mark was not at the right place, as I knew. But my changed mark was gone, because those guys have painted the balancer while rebuilding the engine. :-(
Now I needed to determine the TDC of my engine. I pulled the spark plug of cyl. #1 (left front) and inserted a long metall bolt to block the piston, when it touches the bolt. I turned the engine and waited till the inlet valve has opened for pulling fuel in and moving back up for compression stroke. Then I inserted the bolt and turned slowly till the piston touched it. I marked this position on the balancer. Then I turned it the other way till the piston touched again. I marked this postion as well. Now I measured the distance between my first mark and the second, divided it by 2 and think, that this should be the TDC-point. Is that right?
If yes, it would be about 3 inches away (early/advance) from the original mark.
Because those guys here in Germany are very unfamiliar with "early" Pontiac engines, there might be another chance, that they have put the spark plug wires to the wrong cylinders (Chevy style). Is there a chance, that an engine runs with one or two spark plug wires at the wrong place?
The engine does not run smooth. You can always hear a kind of spitting. It hesitates while cruising. It smokes a lot while accelerating and does definitely not have the performance it had before the rebuilding. The smoke is unburned fuel. You can see the unburned fuel on my garage floor, even when the car is warm.
Those are a lot of questions! I am still learning to use this forum. It so different to the forums I am used to, and I think it is a bit complicated and confusing. But I am very glad, there IS a forum with a lot of friendly, helpful people!
