Help please - Cam timing experts

[gtsdude]

Was your vacuum advance disconnected when you checked timing?

 

[yellow rose]

Sounds like the OP has several issues. One is he needs to verify TDC. Use a positive stop in the spark plug hole. Turn the engine by hand clock wise until the piston touches the stop. Mark the damper. Turn the engine by hand CCW until the piston touches the stop. Mark the damper. Measure the distance between the two marks and divide by two and there is where true TDC is on that damper.

Next, he needs to put the engine on TDC #1 cylinder, in overlap (so #6 cylinder is firing) and look at the valves on number 1. If the intake valve is open more than the exhaust, the cam is advanced. If the exhaust is open more than the intake the cam is retarded. If the valves are off the seat the same, that cam is in straight up.

That doesn't say the cam is in correct to the card, but you will know where it is.

 

[skep419]

Sometimes you wonder what ever happened.......

I had the same problem with the first engine I had built, the shop lined the timing marks up dot to dot (keyway at 12:00). The correct dot is really hard to see on those cheap chains.

 

[middleagecrisis]

Regarding the compression readings, you should have no more than a 10% variance between cylinders. I don’t think this is causing the issue you’re having, but the cylinder with 135 has something going on with it. That’s a lot of compression for such a short duration cam. If anything, the ignition timing should be retarded, not advanced to make it run properly.

 

[67Dart273]

Regarding the compression readings, you should have no more than a 10% variance between cylinders. I don’t think this is causing the issue you’re having, but the cylinder with 135 has something going on with it. That’s a lot of compression for such a short duration cam. If anything, the ignition timing should be retarded, not advanced to make it run properly.

Uh, heh...........this thread, never answered, was from 2017..............

 

[middleagecrisis]

Uh, heh...........this thread, never answered, was from 2017..............

Sorry, skep419 resurrected it and I didn't look at the post dates. Sucks when people never follow up with the fix or cause of the problem!

 

[RustyRatRod]

Sometimes you wonder what ever happened.......

I had the same problem with the first engine I had built, the shop lined the timing marks up dot to dot (keyway at 12:00). The correct dot is really hard to see on those cheap chains.

I don't wonder. WHen people ask advice and then fall off the face of the Earth, I just stop givin a dang.