More problems. Was running well then just quit. Any attempt to restart and it acted like it was out of time. With cap off, I'll set engine to TDC, the rotor to #1, rotate the engine one turn back to TDC and the rotor is one or two ticks off. Go more revolutions and it's further off still. Sounds to me like something inside let go, but no odd noises. Also, when I look up plug wire position for these engines I find 2 versions. Firing order is the same. One with #1 near the front and one with #1 at the rear. Thanks. 72 350 4bbl.

 

The wire position doesn't matter. All that matters is the wires are in the right firing order and the rotor is pointing at #1 wire when the #1 piston is at TDC on the compression stroke.

 

OK. That doesn't answer why the crank makes a full rotation and the dist. does not.

 

Pull out the distributor and check if the pin holding the gear in place is broken . If it’s good you’ve probably jumped time.

 

It's a new distributor so it's fine. If it jumped time, what is involved there? Timing chain? I would think that if the chain jumped a tooth, the dist. would still make a complete revolution with the crank, no?

 

New distributors have failed and not uncommon. Remove and inspect.

 

I've used 2 dist now and no difference

 

The distributor turns 2x for every 1x of crank rotation. As stated above, as long as the firing order is wired correctly in the cap and the rotor is pointing to #1 with #1 cylinder at tdc on the compression stroke the engine will run. The difference in the two distributor cap wiring diagrams is one is for points and small cap distributors and the other is for an HEI. Notice that the firing order is the same. It mainly had to do with wire lengths in premade kits, so the distributor can be positioned to where there is no physical interference with the manifold or the firewall during adjustment.
This is for points


This is for HEI, note the 4 screws in the cap vs the 2 above and the extended timing tab.

 

Dumb question I'm sure, but how to you distinguish the compression stroke with engine intact?

 

Put your finger in the #1 spark plug hole and turn the engine until you feel pressure pushing it out. The balancer will be close to lining up with 0 on the timing tab.

 

Oldcutlass you have it backwards. The distributor turns HALF as much as the crank, not twice as much. He may be expecting to see something else.

 

Thanks

 

If you have never inspected the timing set, or replaced it, it is possible that the OEM nylon covered cam sprocket has worn out and some of the nylon has disintegrated causing the chain to skip.

 

Sorry brain fart, don't know what I was thinking at the time.

 

OK got back on it this morning. Set #1 cyl to TDC on the compression stroke verified by using the comp. tester. Set dist. (HEI by the way and it is new and one of two I have tried) to #1. Checked and rechecked the wires. Cranked engine, spit and sputtered, shot fuel thru the carb, etc. Reset #1 to compression stroke. Removed cap and rotor is pointed to #4. Any ideas? As I mentioned, it was running fairly well when it just quit and when I tried to restart, it was out of time. Thanks.

 

Put the number one wire where the rotor is pointing to and wire the remaining wires from there.

 

OK did that. No go. Reset #1 tdc comp. rotor about 45 deg. behind its last position.
Figure it's got to be cam or timing chain. Time to get dirty.

 

If you rotate the crank back and forth, how far in each direction does the crank move before the rotor begins to turn?

 

Moves with the crank

 

Ok start over, put your thumb over spark plug hole cylinder 1, crank engine until compression pushes your thumb ,immediately stop cranking. Look at the timing mark on the crank, it should be close to zero. Manually move the crank to align mark to zero. Now check where the distributor is pointing, it should be pointing toward number 1 cylinder AND the wire to number 1 cylinder should be aligned directly over it. Next, moving COUNTER clockwise check firing order first is 1 then 8,4,3,6,5,7,2. If all this is done correctly the motor should start as long as you have fuel and spark.

 

Thanks, but I've done all that repeatedly. The issue that has not been addressed is why did the engine die, then on restart was way out of time? No clunk, no clatter, nothing.

 

Only way to be sure is to check out the timing chain and sprocket alignment to see if it jumped a tooth.

 

That's where I'm goin

 

Before tearing it apart, let me ask you this; did you tighten the distributor hold down bolt before trying to start?
if you don’t, sometimes the distributor will move when you crank the engine.
Another thing you can try is to move the distributor either direction while trying to start.

 

Confused over these timing marks, have not seen this type of crank spocket before. Is the mark at the key or the one over to the left?

 

In yours, the one to the left on the crank sprocket should be at the 12 o'clock position. The chuck should be about 2 o'clock..

This is where my original (not OEM) set was positioned before I replaced it.



This is the replacement set, before re-installing with chain..

 

Assuming it is way out of time, how does this happen? Also would the camshaft have anything to do with this and should it also be replaced?

 

My guess, after reading through the more knowledgeable responses above: Is there some way the distributor gear drive teeth on the cam shaft have become compromised? Worn, or perhaps broken?

 

The dist. is new and I got as good a look at the cam gears as I could with a mirror and flashlight and they look ok
Should the cam be replaced at this point if needed?
Can the cam be removed without pulling the lifters?

 

Make sure your pully mark is still at 0

 

?

 

[QUOTE=Roger60;1233701]Confused over these timing marks, have not seen this type of crank spocket before. Is the mark at the key or the one over to the left?

The key in the crankshaft should be at the 2 o’clock position not straight up. By pully mark I meant timing mark on crank dampener

 

you will have to remove the intake, valve covers, rockers, pushrods ,lifters, to replace the cam.
i don’t think the cam is your problem, but I suppose it could , inspecting it can’t hurt.

 

Is this the same engine you were addressing in the 72 350 cooling issue thread?

https://classicoldsmobile.com/forums...-issue-143120/

 

Yes, but I found the cause for that. Kinked lower hose. This engine is in a street rod so it's been trial and error finding suitable parts. Thanks

 

I knew that. My turn for the brain fart.

 

Just looking at your picture of the timing gear set it looks like its set up wrong. AS stated above the keyway needs to be at the 2:00 position with #1 piston at tdc with your marks lined up at either the 6/12 or 12/12 position, your choice.

 

Hard to tell if the crank gear has a key way in it to stop it from moving, could account for the change.

 

I think the key way is inserted and holding. I don't believe the bottom sprocket on the crankshaft is aligned correctly, as others have stated e.g. key way should be @ 2 o'clock position so the marks are aligned correctly for a TDC installation. I believe that sprocket has three positions ("A" = Advanced; "0" = TDC; "R" = Retard). If it's using "0", the alignment is incorrect.





3113 (Just a visual example from Summit) >> https://www.summitracing.com/parts/clo-9-3113

 

Well there's the problem. Have to figure the dist. was not seated properly. Morale: check out the used engines you buy. Other than this, inside looks good, obviously a recent rebuild. Thanks for all your responses.