Would a machine shop have caught this? If not, what can I do?

If you read my prior post you know I was having problems getting my car to idle right after a head and intake install.

After removing and reinstalling my intake I got all the vacuum leaks taken care of but when I set my timing at 10deg BTDC I was idling at about 1200 RPMs and I couldn't get the carburator to adjust any lower. It runs really good at about 10deg after TDC...

Now it's starting to look like it might be that my balancer has slipped after all. I'm not positive yet, but I bought a replacement balancer just to check it out. I don't have anything else left to check since I have checked or replaced everything else.

This brings me to what might be a problem. I only have about 50 miles on this engine and about 2-3 hours idling and tuning on it in my garage before replacing my heads and intake. I don't know if when I had the machine shop balance the assembly the balancer had already slipped or not. If it had wouldn't they have caught it? I would think that if it had moved in the area of 20 deg that the balancer would be ounces off, not just grams.

If they had tried to compensate for the slippage where would they have added or removed the weight? Would it have been from the balancer, the flywheel or the crank?

I know this could be bad but is there anything I can do short of disassembly and rebalancing if it turns out this is the case? Would a Fluidamper be a possible solution if the balance is way off? Or should I replace my flywheel and balancer with stock parts? I don't know the balancing procedure so I don't know what parts would have been way modified... If the balancer was greatly off wouldn't they have just modified the balancer?
I can't see that they would have made major changes to the crank.

This is a 302 with 50 oz. inbalance.

Thanks for any help or suggestions.

If you don't have a copy of the balance sheet, you might just call the shop up and see if they still have it. I think the weight is usually taken off of the crank, that way if you do need to replace the balancer it will still be somewhat balanced. I suppose there might be different methods though?

I'd call the shop up and explain what's going on. It seems that if it was slipped beforehand, the imbalance would have been enough to make them think to check it.

Hope you get it worked out!
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They take the weight off the crank? Bummer for me.

I don't have a balance sheet; I didn't think to ask for one and they didn't offer either. I had the work done around last april so I might not be able to get it now either.

I've never wished I'd been ripped off by a machine shop before but I do right now. I would rather they hadn't balanced it and charged me for work thay didn't do.

While it is possible for the outer ring of the damper to "slip", IMHO, I don't think that it happens as often as it is talked about (I could be wrong though). Further, the counter weight for engine balance is typically on the casting (not the ring that slips); at least it is on the 28 oz dampers that I have seen. Has the front cover been changed? If so, perhaps the pointer is in a new location that is not compatible with your damper. Just some thoughts.. not much help.
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I put together an '88 roller black and dropped into a '79 pace car. I reused the front cover from the '79 because most of the later covers don't have the boss for the mechanical fuel pump. Besides it was still good.

My pointer is on the passenger side just like the pointer for the later cars. I guess it's possible that later pointers are in a slightly different location... Anyone know for sure?

The balancer I used is from an '82 GT. I only used it because I acpuired it and the matching flywheel about ten years ago and never used them. I didn't have the money to buy all new so I just used what I had and since the flywheels use in the later mustangs were different I thought the damper from the same car would be a better match. Looking at it on the car is looks like the rubber is protruding now. I'll swap them out tommorrow to see for sure. On Friday I'll pay a visit to the shop that did the balancing for me.

FWIW the 28oz damper that came on the car has the same basic design as the later ones and it looks to me that the counter weight is on the outer ring too.

The outer ring is what will move. The inner ring is a casting and is keyed to the crank. I doubt that would cause an inbalance. I also believe that Ford used only the right and left side of the timing chain cover for the timing pointer, and they are always in the same place (not moved up or down) in relation to the balancer. My friend's 351 crate motor actualy came with a balancer (ATI) I think with timing marks for either right or left pointers, so that leaves me to believe that the pointer on the timing cover hasn't been moved or the balancer wouldn't work correctly.
[addsig]

Ford did use more than one pointer on the passanger side so there are diffenences in some of them. I have never seen one actually slip, but have seen guys with the wrong pointer. To check, just bring number one up to top dead center and see if it is close to TDC at the pointer if it is not then you either have the wrong pointer or a slippage problem as it should line up right at TDC when the piston is there. hope this makes sense. Good Luck

I find it hard to believe that you can't get your motor to idle below 1200rpm [img]/phpBB/images/smiles/icon_rolleyes.gif[/img] even if the balancer is off.

First, find TDC to see how far its off...then, mark the balancer to see if it moves/slips more. Often most balancers are off a couple of deg's anyways.

Try adjusting your carbs idle setting...I'm sure it can go lower then 1200rpm's

The high idle turned out to be a vacuum leak that I kept missing. I'm still having problems though...