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Timing off. What gives?

21K views 128 replies 12 participants last post by  Lemans guy 
#1 · (Edited)
So I was gonna check my initial timing since breaking in the engine. Started up on first hit on break in, The distributor is set where it runs its best by ear. I took the timing light to it and it was about 2" off the mark. I moved the dizzy and it don't get any closer . What gives? Is my dizzy one tooth off? I did install a new oem style damper from butler. Tried putting the timing light plug wire on the #2 and #8 wire just to see if it gets any closer to the mark, but it did not
 
#4 ·
With any aftermarket balancer you should verify TDC and make sure the pointer and balancer match up. Put cylinder #1 at TDC. If the tdc mark on the balancer is not matching the pointer on your block then you need to get an adjustable timing pointer. Or use the factory pointer on the block side and add timing tape to your balancer. Here’s a link to some timing tape. This one has different strips for different size balancers and its only a few bucks

https://www.summitracing.com/parts/...ezVWX-KjTENIZhwefllJ_zTqwnNyERSBoC9IUQAvD_BwE
 
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#5 ·
Both my timing chain gears were set at 12:00 position. New BP damper only goes on one way. Then set number one piston on compression stroke and TDC. then dropped the distributor facing close to the number 1 plug and started my firing order there going counter clockwise. Fired up on first hit on breakin. I removed vacuum from distributor and plugged it, Timing light wire on #1 plug. so anybody see any reason why my timing mark is so far from my marks on my timing cover?
 
#17 ·
I will try moving the number 3 wire away from the number 1 tomorrow, see if that changes anything. Thought the new damper could be off but when I set the distributor it fired right up the first time. I think I will rent another timing light from autozone tomorrow. Got to be something simple.its not rocket science lol.
 
#18 ·
The battery. You could try grounding somewhere on the block, just for laughs. Jim knows about balancers and just about EVERYTHING else. He's the Obi one Kenobi of the forum :)

You can temporarily time it by ear and advance it till the engine pings or the starter strains, then back off till they don't otherwise you'll damage the engine.
 
#20 ·
You should be using cylinder 1 for your timing light. If you can move the distributor until the engine dies, then your timing is in fact changing and the issue is with your visual cues. You will need to follow GTO44's link and then use an adjustable timing light.
 
#21 ·
You installed the cam gear 180 degrees out of phase with the dot at the 12:00 o'clock position, it should have the dot at the 6:00 o'clock position and the crank gear's dot at the 12:00 o'clock position (dot to dot). When gears are dot to dot, the engine is actually at TDC of cylinder number 6 compression stroke and TDC of cylinder 1 exhaust stroke. Your timing marks are 180 out on the damper, that is why it is confusing you. To prove my point - put the timing light on cylinder number 6's spark plug wire to set your timing, it is incorrect but will work. To fix this error properly you need to remove the cam gear and reinstall it with the dot at the 6 0'clock position (dot to dot). Put cylinder 1's spark plug wire in the distributor cap location facing the driver's seat.
 
#22 ·
I set it per Rocky Rotella's book. But I tried it anyway and its actually in the same position as #1 . Tho I did try again to get it to tdc by turning the distributor and got it to tdc but was running pretty rough, but did not die. The carb has not been messed with since it was running last and used to run decent. So I am still at a loss.
 

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#23 ·
First, let's clarify the timing "dots" on the cam/crank gear. Prior to 1967, the "dots" were shown to be positioned with the cam gear at 6 o'clock and the crank gear at 12 o'clock - or facing each other.

If I am correct, beginning in 1967 with the 400CI, the timing alignment went to 12 o'clock on the cam gear and 12 o'clock on the crank gear.

Why? I don't know. I see in my '68 Service manual a photo of the rotor in the "No. 1 position" which is actually the No.6 position. HOWEVER, I can see some of the carb in the photo and it is a Rochester 4-Bbl which indicates an older engine, pre-1967. Manuals are sometimes not 100% accurate and do slip in some "older" photos. So the reason for th "dot" alignment change is most likely due to a re-design in the distributor - possibly the position of the vacuum advance and its relationship to the engine and its movement for adjustment?

However, either position will work, so no need to rip apart the timing cover and pull gears & chain. With the timing dots are aligned at 12 o'clock, the number 1 piston is put at the TDC firing position. When the dots are aligned with cam gear dot at 6 o'clock and crank gear at 12 o'clock, the number 6 piston is put at the TDC firing position - making the No. 6 the new No. 1 and then you follow your firing order from there (timing is 180 degrees off).

Of note, and mentioned this before, I used the dot-to-dot alignment on a '68 GTO gear/chain replacement thinking, and being told, that this was how you did it, right? Wrong. The engine would pop & sputter and sometimes almost run depending on where I moved the distributor. But, it would not start. So I parted out & junked a perfectly good running car (a $250 purchase back then) because I thought the engine bit the dust when the chain broke on me. If I had only known. :banghead: So that should clarify the timing gear "dot" alignment.

Seeing your engine is running, but timing off a bunch, my experience says it would not run at all, let alone pretty good, if the timing dots were 180 degrees off from the get go.

Make sure you are using the No.1 plug wire for timing and keep other wires away. I clamp my clamp down by the spark plug and away from other wires, not up top at the distributor cap.

To do the timing tape thing, I feel it wouldn't be as accurate as it could be with the best way to do this is right when you align your timing gears and use a timing wheel and piston stop with the heads off. This I would think to be the most accurate way to find TDC and then affix the timing tape as lined up with TDC on your timing cover indicator "0". Now i have never applied, nor used a timing tape, so my thinking on this may be wrong. I also have a timing wheel and piston stop and have never used them, but they look impressive in my Craftsmen tool box draw. LOL

You can certainly still get close using a piston stop that inserts into the spark plug hole and knowing both intake & exhaust valves are closed as the piston comes up on the compression stroke. This could be used to see if the timing gears were not aligned straight up as your timing mark on the balancer will be off. Here is one type of a piston stop: https://www.summitracing.com/parts/...MIypCv98SB5QIVjobACh1owgx7EAQYASABEgJusPD_BwE

There was a forum member (and I simply could not find the post as it may have been a spin-off of another post we had going) where his timing was also way off as yours. Turned out it was the crank gear. It had multiple keyway's so as to advance or retard the cam - many crank gears use this adjustability. He had misread the gear as it was poorly stamped and aligned a keyway marking when indeed the alignment dot was slightly to the left, and not having a keyway slot below it. He had even posted pictures and that was what I was looking for as you could see how lightly the correct alignment dot was stamped. Once he corrected that and put it all back together, the timing was perfect.

So this could be the issue if you used a crank gear having several keyway slots to advance or retard the timing of the cam through the crank gear. The piston stop as mentioned earlier might be an indicator of this before you go pulling things apart.

Found another "weird" fix on the H.A.M.B. website. A member was having the same experience. All kinds of suggestions, none of which worked. The fix? The distributor cap. It seems he installed an exact same second distributor to see if it was a defective distributor. Same results. Then for some reason he decided to try different parts on the distributor, part-by-part. First was the distributor cap swap with a different one he had. Bingo, timing went to where it should have been. So the cap (maybe made in China) was somehow causing an effect on the timing reading at the crank. I can't imagine how, but who knows. Very "weird" and I have never heard of such a thing, but......... So as simple as this sounds, maybe go to your favorite auto parts store and get another cap. If it works, great, if not, then you have a spare all ready to go when you change out the cap when it wears out. I like a distributor cap with the brass contacts over the aluminum. This is what I always try to get if available.

If me, I would not invest a lot of time in this as long as the engine ran good, no overheating/pinging, and you can time it by ear/feel. My last 400 build I could not get it to time using the timing mark on the balancer & timing cover no matter what I did. So I gave up and just timed by ear/seat of the pants. I am constantly learning things myself and when I tore the engine back down to inspect the damages (lost oil pressure), I learned at that time that I had a crank hub, not a harmonic balancer. The hub was used on later production 1970's low performance 400's. It was solid and very small in diameter, so it would not work on the 1972 timing gear cover's scale. It was a junkyard engine and bought that way be me and reassembled that way by me. Who knew? It ran fine, but always had a slight vibration, now I think I know why. :yesnod:

So it is up to you on how you want to proceed. You can continue checking your timing, timing advance - looking for worn/loose parts, stuck weights, weak/missing springs on the weights, new cap/rotor, or pull the timing cover and check the timing gears and dot alignment again. You could use a piston stop and see how close your timing marks actually are in alignment to verify the mark on the harmonic balancer is correct.

So whatever you try, keep us posted of the results and we should be able to narrow it down and get things right. :thumbsup:
 
#24 ·
Glad I took pictures as I went through my build. Pretty much answers two questions anyway. I am gonna change out my distributor cap and rotor. Thats about the only thing I did not install new. I will see if napa has a piston stop also. Butler performance sent me a label and postage if I wanted to return the damper to get it checked. But I was thinking if I set it on tdc and dropped my distributor in and it fires up it must be good???? I tried a local auto parts store for a timing light rental (In case mine is off) but they don't have such a relic lol.
 

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#25 ·
Just curved a distributor for a GTO and the dist cap felt tight but was not in the locks on the distributor,....I see this sometimes, I always check those locks on the cap with a mirror to make sure they are st correctly. A similar wrong set up could mess you up if cap spins independent of the distributor body.

Just a note the distributor gear has a dimple mark, it is there to index the distributor gear with the rotor tip. The rotor only goes on one way way with square and circle mating underneath, they can be forced wrong as well. Gear can be put on wrong and will cause dist vacumn can to hit intake.

Engine can be right and distributor can be put in 180 off as well. So make sure. Rotor and gear are on right, and rotor tip is not 180 off. It must be pointing at or just a few degrees before #1 spark plug, when #1 at TDC.

You can mistake tdc compression for tdc exhaust stroke, ...double check
 
#28 ·
Red yes,...very simple put your rotor on first...make sure it is on correctly, square hole in square round in round!

They made it that way for guys like me! But they can be force fit and screwed on wrong,...so first verify it is on correctly.

Then lay your distributor on the bench, I use a rubber mat,...and point rotor tip straight up...

Now look down at the roto gear,..you should see a dimple on the gear also facing up., ...if so your gear is correctly indexed.

If you don’t see it, lift it up, don’t bust the rotor tip and spin the gear 180,...is the dimple there? If so you need to reindex it.

Just face the rotor tip up agin and knock out the roll pin, spin the gear over so the dimple is up and insert the roll pin.

Don’t forget your shims.msince you are reworking it check the end play on the gear with a feeler gauge....GM spec is .15 thousandths on aluminum distributor and 10 thousands on cast iron. It is not engine work, does not have to be that exact.....when they start getting up in the 90 thousands gap they give timing problems, rebuilt ones usually come about 35 thousandths..

If you shim it use hardened dist shims, Moro’s sells packs of them for a few bucks.
 
#31 ·
I think I would not be adding more timing until you can figure out your base timing. GTO44 and Red I think talked about using an adjustable timing mark and or timing tape. Timing tape is just a way to mark the balancer and read the timing off that. It is good because it goes out real far.

So if you set #1 at TDC Compression of course,...and if the balancer is not messed up,...then putting timing tape on would give you a way to measure where the timing currently is. Since the car starts after you put the tape on Fire it up, vac disconnected and plugged and at idle speed,..like 800 or so read where the strobe flashes on the tape. Say it is 12....well that is your base timing. 12 BTDC and where it is now.

Using GTO44 advice get an adjustable timing marker or improvise one with mechanics wire, or a coat hanger or a mark, and put it at the zero mark on the timing tape.

That is zero because you already set the #1 at TDC and started the tape from there.......now use the new zero mark as TDC. It will then let you know how much you have advanced the base timing.

Once that is known, then you can use a prodcedure to rev it up to where it stops advancing and figure your total timing, centrifigal + base = total,...which you want at 36 and it can be fine tuned from there.

You strobe should fall somewhere on that timing tape, at least giving you a place to start.

Now it the balancer is wrong this will. Be wrong so you already know you have to make sure that is right first.

You also could have a cracked or broken distributor, and it won’t rotate properly, so another r test is to just substitute a known good distributor and retry, maybe you already did that, but it will eliminate a lot of possibilities.

Your timing is changing when you turn it as the engine runs better or worse.

Keep at it you will get it!
 
#33 · (Edited)
I will be getting a piston stop and a timing tape on monday. Speed shop just closed. So I would like to identify true tdc and and see where the mark on my new butler balancer lands. So I am just guessing now, my mark should land near tdc or close to it with a piston stop, not 2" away.After I get my timing squared away what should I tackle next? Distributor, carburetor? What order? Does anyone here rebuild distributors? Or is it prefered to have the car there? I was turning the advance on mine and it seemed like thos springs were a little tight. But what do I know. Been reading up on it tho.
 
#34 ·
I will be getting a piston stop and a timing tape on monday. Speed shop just closed. So I would like to identify true tdc and and see where the mark on my new butler balancer lands. So I am just guessing now, my mark should land near tdc or close to it with a piston stop, not 2" away. After I get my timing squared away, what should I tackle next? Distributor, carburetor? What order? Does anyone here rebuild distributors or is it prefered to have the car there? I was turning the advance on mine and it seemed like those springs were a little strong. But what do I know . Been reading up some on it tho.
How about all of the above.

The engine will probably run a little hot initially being new - things are tight and need to break/wear in.

You should be able to get pretty close to the TDC with the stop. Remove all the spark plugs so you have no compression fighting you. Then follow this YouTube video on how to mark the balancer, turning engine one way and then the other, and splitting the difference for TDC. https://www.google.com/search?clien...dead+center#kpvalbx=_xUSZXfOUHrKl_QbZ9bXYAQ31

Red Skeleton answered your question - advance timing can help to run the engine cooler, while retarding can cause the engine to run hotter. But don't use timing advance to cure another problem that may be causing the engine to run a little hot.

Other factors can also cause the engine to run hotter - such as a lean condition.

Stomping on the car is going to make it run hotter as more air/fuel fills the cylinder and adds cylinder pressure, ie heat. So expect temps to rise and then cool after you are done hammering the engine.

Never rebuilt a distributor, so can't help. Went new/aftermarket with my 455 build and have purchased rebuilt distributors from the auto parts store - then just run them as is, no fine tuning or tweaking. The only distributor I had set-up was the dual point on my 409 engine and it was set-up by the local machine shop using one of the Sun distributor machines, so I didn't have to do anything to it but run it.
 
#40 ·
Lurching or trailer hitching is often a symptom of too much advanced timing,... turning the timing up at idle just to get a smooth idle is a mistake ......without knowing the rest of the story.

These cars will run great at in a range of numbers including 24 degrees of timing at idle generally, but you must be grabbing at least 10 of that from vacumn timing.

If not and your base timing is 24, your centrifigal timing must be 12 or so. Most distributors are way over that, so make sure too much timing will cause detonation.

Don’t just turn up idle timing until it “Feels” good or “sounds” good,.....it should feel good and sound good and be correct throughout the power band.

You can make it feel and sound good at idle,...and it will lurch ping and detonate throughout the power band.

So make sure.
 
#41 ·
Thanks Lemans Guy.
Logic would dictate that if I have some low speed lurching and no pinging and within 36 degrees total timing, that I should be able to pull the vacuum advance off to stop or minimize it-no go.
So I'm going to continue to retard the timing to see if I can time it out. My car is amazing in that I can't make it ping but can get to that other warning sign of a strained starter on startup but she still lurches:x.
 
#42 ·
Red do you have 24 degrees of base timing and 36 total?

You can get too much timing too early and or to fast and you get the problems on acceleration as the springs may be so weak they pull centrifigal timing in on top of your base timing.

Or they just advance the weights so fast it lurches or pings etc.

I am sure you know your springs are on correctly.

Just make sure you know when centrifigal starts and stops and how much,..lurching could be other things as well.
 
#44 ·
So no one seems to be sure what causes the timing to be off two inches. So correct me if I am wrong. As long as I set it where it runs its best, I should set a timing tape on the balancer and get total timing from there? So all I would need to know is where is there? Hard to mark it while its turning lol.
 
#46 ·
If you have verified you are at TDC on #1 , then I would just mark the balancer with some white paint (paint pen works well) and then check what you are dealing with initial and total timing. That said, I suspect the dampener was installed incorrectly.
 
#45 ·
So RM,...you have it mechanically at TDC, dead on......

So if you balancer is OK....Zero is at the Mark on the balancer

Put the timing tape starting there and make a corresponding mark on the engine.

So you have all three at zero.....The number one piston mechanically, ......

the balancer mark is now at zero with the piston..

Start the timing tape at balancer mark

And mark the engine next to to zero on tape and balancing mark....

Now try it and see where the timing light strobe falls........

You are setting the Advance timing light correct, right?.......

..if you set it for 10 degrees advance it will hit the strobe at zero on the balancer mark but read 10 degrees on the light......

Zero on the light should be zero on the balancer.
 
#47 ·
Didn't read all the posts, but seemed to get the gist that with the piston at TDC Compression, the timing pointer on the cover is not aligned to the balancer mark. The mark is '2 inches' off from TDC. If this is the case, the only cause is the balancer itself: either the wrong one or the outer ring has slipped (common, especially on Chevies). The harmonic balancer hub is keyed into the crankshaft snout, and cannot be installed incorrectly. It WILL be in the right location on the crankshaft, and if not slipped or incorrect, it WILL have it's indicator meet TDC at the pointer if, indeed, the engine IS at TDC COMPRESSION. (not exhaust).
My bet: wrong or slipped balancer.
 
#48 · (Edited)
The balancer is a new one from butler, and only installs one way on the crank. When I used a piston stop and I mark it on the balancer at stop both ways, and split the difference the mark on the balancer is dead on with the tdc mark on the timing cover. The issue is, when set the distributor to run well or use a vacuum gauge it is about 2" from tdc. If I try to move it near tdc it wants to die.I only have a 068 cam, nothing crazy. So why would it read that way? I have two timing lights and both read it in the same place. It runs well which is not the issue. I would just like to be able to read it on the #s or at least find out what causes this. So far searches only tell me if it runs well yada yada yada... no real answer.
 
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