Here's a puzzle I'd like somebody to explain, I can't get this engine to run. It ran for many years and now its quit running due to ignition. It has spark and fuel. I can take the distributor out of the engine, remove the valve cover to observe #1 rockers, pull #1 sparkplug to feel compression and I painted a fresh mark on the harmonic balancer at 30degrees. I spin the engine with a 'Bump' switch, observe the #1 rockers and when on compression stroke I align my timing mark to the pointer then drop the distributor in and align the rotor with #1 on the cap. I then spin the motor on the 'Bump' switch a couple times and repeat my procedure to bring the engine back to #1 for ignition and the rotor is now pointing at #8; I repeat the process again and bring it back up to where #1 should fire and the rotor is now pointing at #5. The distributor is spinning at a different rate than the valve train, it is retarding. The distributor gear looks intact, the teeth show wear but none are missing or knife edged - I actually have 2 different gears that I've tried, an MSD and a Ford gear. The car came to me barely running with a Ford distributor that had the bottom bearing totally missing, I replaced it with an MSD and the car ran briefly. The timing gear must be OK or else I'd have valves bumping into pistons. Its like there is a tooth missing off the cam gear? is that possible? When I set the distributor into the engine (I've done this a couple dozen times now trying to figure the problem out) it feels engaged into the cam gear, when I tighten the distributor holddown you cannot rotate the rotor, it is firm. Heres' the car:
Have the same balancer? Or is it slipping? I would check that first because it’s exposed, then dig into the timing chain. Like mentioned could have sheared a tooth or two if it’s the oem nylon unit.
Timing gear shed its nylon teeth. Ford small blocks aren’t interference engines like a lot of ohc engines, so it’s probable that the valves are ok. You might want to run a compression test before tearing the front off the engine.
From the symptoms you described, it is one of 3 things- the crank sprocket woodruff key has sheared, the cam gear pin has sheared, or most likely the cam sprocket teeth are missing. Ford used a cam sprocket with nylon teeth for a few years for noise reduction and they were good for about 75K miles.
Have you rocked the balancer back and forth, to see if the rotor rotation moves with it's movement or is there a large delay between movements? I'm thinking timing chain/gear system.
The balancer seems firm, I've got the belt off it and it isn't driving anything. The engine is high performance, built by Carroll Carter with dyno sheet showing over 500hp, so I'd guess if it were timing gear/chain the valves would have clipped a piston by now.
Pop the cap, grab the rotor and see if it will rotate. Sounds like the dist. gear isn't secured to the shaft. I've seen those hardened spring pins crumble, allowing the gear to spin some on the shaft. Seen this more than once. Good luck!
This.... Don't forget that the distributor shaft also spins the oil pump, if the distributor gear pin is sheared the gear will turn but you'll have shaft 'slip' from the resistance of the oil pump. May be an issue with the pump, although most new/rebuilt distributors come with roll pins securing the gear that aren't really strong enough. An interference-fit solid pin is a better choice.
Yup, the rotor is firm, when I drop the distributor in I can feel gear engagement, when distributor is locked down with the clamp I can't turn the rotor, its firm.
I picked up a fresh 351W, Al heads, cam etc. Just broke in, never really run. I did a cursory inspection of my new purchase. It had double roller timing set in it. However, the backside of the cam gear was grinding itself on the cam retainer plate, causing enough drag that it stretched the chain. Had to trim the offending piece off of the plate, and buy a new timing set. Not saying that's the issue here, but all sorts of contributing factors can "play" with the cam timing issues.
If the distributor gear roll pin hasn’t sheared off, pull all 8 spark plugs and check engine compression. If it’s low on all 8, you have valve timing issues.
Watch the rotor spin with the cap off to try to see the 'slip'... A sheared pin doesn't mean the gear turns freely on the shaft, it takes some power to turn the oil pump.
Ive had a similar experience with one of my 351w, turned out it had a 302 firing order cam it. Once i changed the plugs around it fired right up.
I've had the distributor gear on & off 2-3 times to replace the Hall Effect PickUp and module etc before i finally figured out the distributor was turning at a different speed than the engine. The rollpin is secure. I believe there is some kind of oilpump drive interference, that that is the original problem and this is the effect of the original problem. When i drop the distributor into the motor I can feel engagement into and can feel the oilpump pressure before the distributor gear gets down into the cam gear.
The connection between the crank, cam and distributor is pretty solid. Plus it is short with the distributor being at the front of the engien. I don't see how any of this could slip and you cans still see the correct operation of the timing mark and valves on number one. However, the connection between the lower distributor shaft and the rotor isn't exactly solid. The centrifugal advance is the connection. Could there be some problem there?
That still doesn't rule out a sheared pin IMO. Easy way to check; pull the distributor, mark the shaft/gear, reinstall and spin, pull and check to see if the marks still line up. Given the relationship of the parts, that's the only way the distributor shaft can be spinning at a different rate... unless the gear on the camshaft is loose or damaged somehow.
Very outside chance of the cam dowel bent or starting shear off. It’s never usually a problem with sbf’s as far as I know.
Had the SAME THANG happen to me with my 'youngster's' 390 P'up.........lose timing chain replacd and FIXED! 6sally6
If this is a FORD distributor, pull the plate that covers the advance mechanism. I've encountered several times where someone has dropped a screw down the square window(un/knowingly) and the screw jams against the timing mechanism sometimes it's immediate, other times its been years. Main shaft of distributor is below theplate and the advance mechanism is the upper portion of the shaft the pickup(points/magnetic) rubs against and the rotor sits on. If this is boogered up the rotor portion will rotate erratically. I've had one instance where the whole timing mechanism partialy sheared away, so when doing a simple check of the advance mechanism by looking for advance freedom/return it seemed to function correctly. But the rotor rotated erratically. Pulled off the plate and the timing mechanism fell off the top of the shaft.
Is the cam firing order for a 351 or 289/302? I once installed a 302 can into a 351w and it took me a week to figure out why it wouldn't start. I had the firing order completely wrong because I forgot which type of cam I installed.
No advance mechanism, it is stock Ford EFI for the Windsor. I wish it were old school distributor and carburetor, I'd have figured out what was wrong in a couple hours, I've been on it for weeks wading thru 2 computers, 3 modules, 2 Hall Effect triggers, 2 sets of injectors and connectors and 2 distributors on an OBD1 system that I can't read on a scanner. I'm going to start pulling the thing apart today, it'll be slow going because of the flawless black paint, I'll post up what I find.
Shouldn’t have to tear the engine apart to inspect cam to crank phasing. Also, if the rotor ends up on a different cylinder randomly it almost has to be something in the distributor. I think… Firing order should be 13726548 or 15426378 I think…..
Are you sure you are on the correct mark on the balancer? The correct TDC mark is faintly stamped , not the groove that goes across the balancer. I had fits trying to time mine until I found out the correct mark is usually covered up in paint and grime.
The stock diameter roll pin isn't big enough in some cases. You can buy a gear with a 3/16" diameter hole and drill the shaft yourself for the larger roll pin. I do this pre-emptively now.
I had a good running 351W that may have a timing gear/chain issue. It would leave me totally stranded only on cold starts, crank, crank, crank.... no start. Come out the next morning and it started at a tap of the key. I never got to the bottom if it and eventually sold the car.
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