Technical 352 FE Timing Jumps Around & knocking

As said above... pull spark plug wires one at a time to see if knock goes away
Pull dizzy cap and advance rotor then let go to make sure it is not sticking and springs are good
Pull cap and rotate engine slowly back and forth, watch rotor to see how long it takes to move

Move spark plug wires on cap advancing them

With that low of compression, perhaps timing chain has jumped and is retarding cam ??

You can pull fuel pump, rotate crank depending which side your fuel pump is on
Take the slack out of the chain opposite the fuel and push on chain with a screwdriver or such

Good luck


Ricky.

 

It’s running, so can’t be 180° out. It’s not a smooth idle, but not a burb and banger. No smoke from Exauhst, no back pressure on cooling system. It just knocks and has a rough not angry but not happy idle. I cam send anyone two videos, one is in slo motion on a timing light and the other is how it runs at idle. It has to be the distributor, timing chain, ignition box??? I have metered and gone through it all per MSD specs . The timing light is showing chaos!!

 

I’ll try the fuel pump trick for sure!!
Never thought of that! All the push rods are spinning while running….

 

As a young lad ,i was working at a service station in Los Gatos,Crider's oak tree service,we had some sharp people working in the service bay's.We had a lot of older people coming in there.On couple had a caddy,it came in for a knock in it.The guys all listen to it and sent it to Saint Claire in San Jose for a rod knock,which was strange since it had low miles on it,It turned out to be a carbon knock . my buddy drove his camaro to our Willow Glen car show and ask me to listen to it as it had a knock on a fresh 431 SBC,it turned out to be a exhaust leak.

 

Low compression across the board with new parts points to cam timing not being correct. That or bent valves.

 

This is probably not your problem but my son had a 4 cylinder S-15 pickup that had a knock similar to yours. His was a stick shift and with the clutch disengaged the knock almost went away, but not quite. Pulled it apart and went to turn the flywheel to get to the other pressure plate bolts and noticed you could turn the engine a few degrees and the damper did not move. Turns out the crankshaft was broken in two at the front main. It was broken at an angle so that it did turn but had slop in it. It was an engine I bought from a local rebuilder and did not have many miles on it when this happened.

When you disengaged the clutch it moved the crankshaft forward until it hit the thrust surface on the main bearing. When it moved forward it took up some of the slop at the break.

If you had this problem your timing would be erratic, both cam and ignition.

 

"Sucked it up and a short blocked it at a local machine shop". In the FE world, experienced FE folks will search out shops with solid FE experience, as, unfortunately, many small shops/ machinists are Chebbie cross-threaded between the ears, with habits. There are common mistakes, the rocker bolts in the right holes, rocker shaft oil holes down, the rear plug in the cam bore reversed, cam bearing oil holes out of phase etc. The low but consistent compression would suggest timing chain jumped or similar, pretty easy to check. Also pretty easy to just pull the timing cover to look for problems or reasons it's having a spaz attack. It's also possible for the cam to walk and a cam lobe to hit two lifters and make noise and chunks, if the cam got loose

 

Pulled the fuel pump, maybe 2° of slack on the crank….
If the magnetic pic up is bad could it be sending bad signals or is the msd box many F’d? Why would it fire with no timing marks in site? Check my photo grabs of it running… these photos where screen shots of a video while idling
I did meter the mag pick up, cap, coil

 

Did you replace the timing chain (or gears) at the rebuild?

 

Were you able to get oil to both banks? Also easy to check if you are getting oil into the up galley is when you spun the oil pump is did you get oil coming into the distributor hole below the gear? The one which would be directly behind this plug.

 

Thinking out loud, is there a way you can lock the mechanical advance out of that MSD distributor? Like jamming the end of a zip tie or something creative like that to see if the timing still jumps around.

 

This is what I'm thinking. Would explain knocking, rough idle, and low compression.

 

I took out the weights, spring and bushings, rotated to spinning momentum and used a lock washer to seize it. I fired it and no luck. Timing is still wacky… it is firing before, after, on set timing and even in random dead spots…. FYI the timing chain checked out and I confirmed proper oil all around since first post. Now it’s just a crazy timing issue with a steady knocking at idle and loader at rev

 

I added cam, and double chain via Comp. And it ran perfect for 400 miles after rebuild… it’s what ever this other guy did… it came home hurt

 

Super longhshot, but easy to check. In the pic, it looks like you've got the 7/8 wires traveling next to each other from the dist to the cylinders. I've run MSD wires in the past that got heat soaked from a tight engine compartment and cracked pretty quickly. There may be a cross spark between those two wires, I would try separating them as a quick problem to rule out. Wouldn't explain your erratic timing light, but you have noticed a problem from that area of the engine. Maybe give those wires a tight bend by hand while you're at it and see if you can see any cracks.

 

Sorry I’m not good with valve work yet, my first motor I built was a /6 and I never mastered that valve system…. So you think the valves could cause the jumping on the timing light? If so I’ll tear it down tonight and inspect

 

I’ll do that, I have them separated with aluminum spacers, maybe I’ll go back to my zip ties, would a meter show a crack on resistance? I will also re clock and run wires now that its back be-bopping

 

You could try the old "run it in the dark and mist it with water trick".

I only suggest your 7/8 wires because I've had MSD wires go bad real fast before. I could see the cracks really easily by bending them. It was in a 67 cougar, with a tight engine compartment and stop and go traffic. motor didn't overheat, but temps under the hood cooked the wires. I always separate adjacent cylinder wires that are next to each other in firing order after that. the spark will literally jump from one wire to the next and fire the wrong cylinder. Electricity is seeking the path of least resistance and the "wrong" cylinder has less pressure than the "right" cylinder, so it jumps across the parallel wires.

Just let number 8 out of those clamps and drape it over the valve cover. Long shot, but you never know? Gotta love internet diagnosis (spitballing)

 

Any chance you could get another distributor and try it? I don't know much about the MSD for the FE.

I'm still very confused by the all around low compression. That would be from improper cam timing or every valve being burned/bent. A cylinder leakdown test will confirm that.

What was done to the heads in the rebuild? I rebuilt my 352 last winter, and had the machine shop put in hardened exhaust seats. Mine was low on compression and the origional 1959 exhaust valves were pretty rough.

 

That’s why I’m hear…
“now accepting all bad ideas!”

 

Just checked timing chain, it’s got some slack but still on the marks (double chain “comp”) has anyone had an MSD 6AL send misfire??? I’m about to get a junkyard points distributor and try that. Ideally I’d like to put my box on some ones motor with same box and see if that’s it? . Anyone know a test other that can be done on the box at idle??
I was able to push the chain in and out slightly after rocking it hand crank to TDC …. Marks on my Amazon 20$ Endoscope look good. I’ll pull the cover tonight or in the am. I saw the thread about valves… going there next but would that make the spark dance like that?? I can’t figure that out

 

No, a valve train problem would not cause "jumping on the timing light". It could cause some of the other symptoms you described. I.e. low compression, knocking noise, erratic idle. One of the symptoms is low compression. The 2 main areas that cause low compression is piston ring wear, and/or valves not sealing. One way to isolate whether it's the rings or the valves is to apply some oil into the cylinders, which if the low compression is due to bad rings the oil can temporarily seal the chamber and cause an increase in compression. You said you applied the oil to the cylinders and it did not result in an increase is compression, indicating the problem could be the valves. Noise in the top end could be interference between the valves and the pistons. I'm just putting together the symptoms you described, and to me they're indicating a potential problem with the valves. As far as timing issues, I don't know what to tell you. Slop in the timing chain could potentially cause that. That could also result in the chain jumping teeth on the cam gear, resulting in a change in cam timing, possibly resulting in valve/piston interference. I don't know, I'm just saying what the symptoms are pointing toward to me and where I would be looking.

 

Just to repeat, what I asked you to do is pull the distributor cap, put a brakeover bar and socket on the crank bolt, then rotate the crankshaft clockwise/counter clockwise while watching the rotor bug on the distributor. If you can move the crankshaft more than a few degrees before the distributor rotor bug moves, the problem is in the timing chain or camshaft gear/distributor gear. If the distributor gear is the improper type or damaged it can lead to timing being all over the place.

If you want to test you valves to see if they are bent, loosen the rocker assemblies then remove the push rods. What I use is a tool made from an old sparkplug and an air hose nipple; break the porcelain center out of an old sparkplug using a punch and hammer, then weld an air hose nipple to the metal spark plug shell. Once that's done thread the spark plug shell into the cylinder, rotate the engine until the piston is at the bottom of that cylinder, then apply shop air to your tool. Air out the tailpipe means bent exhaust valve, air out carb means bent intake valve, air out oil filler means piston rings not sealing.

By the way, nice looking engine.

 

I'm not sure the timing jumping around is the main cause of your problem. I see the 60 psi compression and the knocking noise as being something to address first. It is never going to run right with that low a compression. You can verify the valve condition using a cylinder leak down test. If you don't have a leak down tester, putting 100 psi air pressure in the cylinder and see if you hear air escaping in the intake manifold or the exhaust pipe. You will always hear some air escaping in the crankcase, but you shouldn't hear any in the intake manifold or exhaust pipe.

Back in the late 60's and early 70's I worked at a Lincoln/Mercury dealer and dealt with a lot of FE engines. I saw a good number with a light knock and it turned out to be the fuel pump. I personally had an FE that had a bent rod. I didn't know about the rod until it broke in the middle. They were also known for valves sticking in the guides if they set for a long time.

 

I have only crossread this thread, but have you checked for a worn down cam lobe yet? That could cause low comp numbers on that cylinder and all kinds of weird noises..

 

PS : You could just pull the valve covers and check the lift on each rocker...

 

I would try another timing light. I have seen the same problem you are having with the MSD boxes and incompatible timing lights. The low compression is the problem I would be looking for. With the bore scratched up in your first picture, I would be looking for the black death on the piston skirt. That will certainly make a knocking noise as well as having ring seal problems, caused from to tight skirt clearance or from over heating with thin bores, which could be a problem with a over bored FE.
A leak down test needs to be done to move on to what to do next.

 

Separate #1 wire and check timing again. This is to rule out wires causing timing jump.
If timing is still jumping it may be in distributor, pull and inspect. Make sure distributor gear is intact and roll pin isn't sheared. Shaft bearings tight but turn freely? Advance parts working properly?
timing chain/gears are next. Chain tight? Keyway/key on crank good? How about cam gear? A problem with these can cause jumpy timing AND low compression.

 

If I remember correctly #s 3 and 7 can't be near one another on an FE Ford.