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Discussion Starter #1
Hello, I have a new-to-me '67. It was running a bit rough with low vacuum. It looked like the distributor was clocked way back, so I moved it up a bit. Now she runs much better. No pinging.

I finally bought a timing light (haven't needed on in years). I'm seeing 30+ degrees of initial advance at warm idle. I've triple checked I have the #1 plug wire. I turned the timing back to 15 degrees initial (~32 total) and it runs poorly again. She stumbles a bit and doesn't pull.

She sees to want 20-30 degrees initial advance at warm idle. Never heard a ping and pull strong, even bogged down. That can't be right? What am I doing wrong?


I believe the motor is '69 302 (351W heads, performance intake, carb and headers). I think the internals are stock.

Thanks,
-Morgan
 

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Make sure you disconnect the Vacuum to the distributor or else you will be seeing that advanced. You need to set it with the vacuum disconnected and plugged.
 

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Someone might have stabbed the distributor on the wrong tooth and caused the rotor to not be in the correct position. Check the balancer marks are correct by finding TDC on #1 and ensure timing marks are correctly aligned with pointer. If not, then you should look into re-installing the balancer so the marks are aligned properly.

You could always re-start the timing process from scratch to ensure it's done correctly if you want:

Mark sure the balancer is correctly aligned with the pointer first!
Mark the distributor and engine block where it currently runs best in 1 color (so you have a reference point)
Pull distributor and re-set so that when fully seated, the rotor aligns with the center of plug #1 (mark the distributor under the cap so you know the center of the #1 plug w/o having to guess)
Mark the distributor with a different color (if it's off)
Pull the vac advance line and plug the carb port
Fire the car and adjust timing to what you need (my 289s like around 12-14+ initial at the start of adjustments, factory recommends 6-8 on a 289 which is never enough)
Lock down distributor clamp and then fine-tune with your butt dyno and ears

Make sure you can CLEARLY see your timing marks and pointer, otherwise you'll get bad data.
 

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Someone might have stabbed the distributor on the wrong tooth and caused the rotor to not be in the correct position. Check the balancer marks are correct by finding TDC on #1 and ensure timing marks are correctly aligned with pointer. If not, then you should look into re-installing the balancer so the marks are aligned properly.
Balancer can only go on in one position.


Thoughts - wrong balancer or timing pointer. Lots of different combinations used throughout the years. Balancer elastomer is failing, causing outer ring to slip.
 

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Balancer can only go on in one position.


Thoughts - wrong balancer or timing pointer. Lots of different combinations used throughout the years. Balancer elastomer is failing, causing outer ring to slip.
Ah, thank you for clarifying that. I've certainly seen the elastomer fail on a balancer before! Luckily, they're not too expensive if so
 

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Besides the possibility of the outer ring slipping, make sure you have the right balancer. The pulley should have 3 bolts. In 1970 Ford changed the location of the lower hose to the driver's side and used 4 bolts on the balancer pulley with timing marks in a different location. Ford also modified the timing chain cover to be a universal fit all with bolt on timing marker where as the 3 bolt system had a cast in timing marks. A lot can happen to a car in 50 years, you could have a mix of parts. Post photos, that's very helpful to us.
 

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Discussion Starter #8
Thanks for the quick feedback!

I'll check TDC this weekend.

At the moment, I'm not hearing or feeling any ping, and the motor pulls nicely. Am I okay to drive? I'm worried I'm going to break something in this 50-year-old motor.

Does old the old rule of turning the advance forward until the motor pings and backing it off a bit really okay for an old mild mod motor?
 

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If it starts ok once the engine has got heat in it and it runs ok without any pinging or other weird noises it should be ok until you can get it sorted out.



I tend to go at setting by ear the reverse of your question. Back it down until the engine doesn't want to run and then slowly advance it until you just get a clean idle. Then go out and see how it runs on the road. That should be a safe setting until you can figure out why the timing marks are off.
 

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I had the exact same issue on my 68.

Start with the obvious potential issues, then you'll have to look at the less obvious if it still isn't fixed.

1. Now that it is running smoother, what is your vacuum reading? Try adjusting the timing with the vacuum gauge. Disconnect the vacuum advance and plug the line. Adjust the timing until you get the maximum vacuum. Compare to the timing light.

2 Definitely check for #1 at TDC then check that the balancer reads 0 degrees.

On mine I was sure the balancer must have slipped, but it was fine.

So I had to dig deeper. I had recently swapped to a 4 barral manifold and carb, which is what prompted me to retune the car and find the odd timing.

What had actually happened was I had introduced a vacuum leak a the base of the carb. I ended up having to sand the spacer to ensure it was flat, check the carb base and switch to thicker gaskets above and below the spacer. Once that was all done the car tuned perfectly.
 

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I went back over my old posts and realized the problem occurred before I swapped the manifold. Swapping to the 4 barrel was part of the fix so the leak could have been at the manifold too. Bottom line, you need to look for hidden vacuum leaks that mess up your fuel ratio. The advanced timing is a sign that the ratio is too lean. Other possible leaks are at the transmission modulator, and Power Brake Booster.
 

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Discussion Starter #13
Investigations last night:

TDC on #1 does not line up with the timing needle. Strange. I rocked the motor back and forth a dozen times and the needle is definitely off, but only a bit. The needle is showing about +5 deg at TDC.

I re-timed the motor to +15 initial (+20 on the needle now). It's happier, but still a bit slow.

If I move the motor up to +20 initial, the vacuum and idle speed peak.

Flade: You might be onto something. I'm on the hunt for a vacuum leak now.
 

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Considering the other upgrades you mentioned, I bet they put a bigger cam in it too. If you don't find a vacuum leak, you would expect your idle vacuum to be a bit lower than normal stock with a bigger cam and it will be happier with more initial timing. It would also like a little more idle speed than normal.


With the 5 degrees off timing marks, I would surmise that your balancer ring has just started to slip. It is unlikely but also possible that it has cracked along the keyway slot and moved a bit because of that so you probably should look at your key and keyway also. It is probably time to replace that or if you just have to keep your existing damper, you can send it off and have it re-clocked and a new elastomer installed and they will press it back together. I had that done to a hipo damper I used to drag race with. I sent it off to a place called DamperDoctor which still looks like they are operating.
 

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Discussion Starter #15
macstang, you're right! I never thought about the cam being non-stock. I managed to talk to the old owner, and he confirmed the Cam has been changed to something more "lumpy". That explains the low idle vacuum and the want for advance. She seems to be running nicely now.
 
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