Hello again
Still having problems with my 72 Cougar.
I have just rebuilt my 72 351c 2v into a 4v. Ever since I have had nothing but problems. I rebuilt it mostly by myself. A friend who is a machinic helped when he could.
The problem I’m having is that the timing is way out of whack. It should be no more then 12 deg and no more then 36 deg total timing. Well mines at 20 deg and total timing is at over 50 degs.
After two months of trying to correct this problem the engine is bossing blue smoke and still timing is messed up. I’ve changed distributors 3-4 times and still no use.
Could it be out that much if the distributor is out a tooth or timing chain is out a tooth?
ino the motor might be f&@“ked and this might be to late for a solution but if and when I rebuilt it again I don’t want this problem to repeat itself. Thanks
Is your vacuum advance set for ported or manifold vacuum? Ported is zero advance at idle rpms, but manifold is ~12-16, depending upon the engine. When measuring timing, plug the lines going to the vacuum advance canister on the dizzy; this gives you the pure mechanical advance settings. Then, add in the vacuum advance and see what that does to your timing.
Also did you replace or validate the harmonic balancer has 0 at TDC ? As they age the rings on the outside can slip a bit and so it may look like 20° and actually be 10 depending on how much slippage there is. Simple in theory to check, but a pain in practice on some motors. Might be worthwhile here.
I’m not saying I’ve ever done this … but do you have the timing gun connected to the correct spark plug wire? You might also try plugging your vacuum advance to initially set the timing.
Lol yup it’s on the correct spark plug. As for the harmonic balancer it new. When #1 piston is up and rotor is aimed at number 1 plug wire the harmonic balancer is at zero.
My vacuum line go’s from distributor to Holley 600.
I’ve tried everything different distributors. When I put the distributor in could I be out a tooth one way or the other that would give me this result. Or could it be when the timing chain was installed could it be out a tooth? Or could it be the cam?
While I’m sure you did, when checking the timing did you disconnect the vacuum from the distributor and plug it off?
My bad! Checked it today with hose off and pluged. It’s 12 and @2500 it’s 30. Which is great so is it ok when vacuum advance is hocked up that it’s 18-20 and @ 2500 it’s 55-60?
The cars chucking the blues bad!
I owned a '71 351C 4V with a dual-diaphragm distributor. At the height of the 1974-5 “my gas mileage is better than yours” mania, I hit upon swapping ported vacuum from the 4300 carb to manifold vacuum. It gave me (yes) 50+ ignition advance at cruise, and bumped mileage from 14+ to 17. Then I began to have hard starting that wasn’t reproducible. Turns out the stronger pull on the advance plate accelerated wear on its pivot bushing, allowing the timing to settle at extreme retard or to even nearly close the points (it was REAL sloppy when the Big Light Bulb finally went on.) I repaired it by drilling and pinning the internal assembly (making it centrifugal-only.)
So, it isn’t the case that you’re on manifold vacuum, is it? This has come up on the forum before. While the engine can run at 50 total on a light load, you probably don’t want to run manifold vacuum with a stock Ford distributor for too long…
The vacuum come from the Holley 600
I swooped out the points for pertronics electronic ignition
Will a harmonic balancer from a 72 351cleveland 2v fit or work on a 72 351cleveland 4v cobra jet?
Can you put the points back in and try it? Check the plug wires? Low fuel pressure? Sounds like too much advance.
Wire r good, fuel pressure is good. Changed distributor at lest four times.
Pulling the motor. I’m done with it! For now. Bought another Cleveland but this ones a cobra jet. That’s why I asked if I can use my harmonic from my 2v on this 4v cobra jet