General question.

If you have a "balanced" rotating assembly and you replace the Harmonic Balancer, do you hose up the balance or, are they generally balanced as a stand-alone item ?

I know 85ish and up small block fords changed their balance scheme but this isn't one of those.

Thanks,

Dawg-a-roo

 

A balanced rotating assembly will have the exact damper, flywheel/flexplate, and clutch pressure plate that will be used on the engine taken into account. With that said, as long as you use the correct 28 or 50 oz. imbalance damper to match the crankshaft, using a different one than it was balanced with won't make any difference unless you're turning it about 4500 RPM on a regular basis.

 

I'm sure this will be helpful, but the big answer is; it depends. ;-)

As BOR correctly stated, the weight of all of the pieces of the rotating assembly are carefully calculated into the overall scheme of things. But if the person doing the balancing made any corrections to the balancer to achieve the desired balance, changing that part will, in effect, render the balance job wasted. A good balance job is typically done to within a tenth of a gram, so it's quite likely all of the pieces in question have had some kind of massaging to get there.

I once bought a 289 from a friend that had it all balanced out, but it was set up for an automatic, and I wanted it for a project with a top loader. I took it back to the balance guy to have the crank, balancer and new flywheel, along with the bobweight sheet to have it redone.

 

Ok I have a question, I just got my 289 a longblock reman from autozone. It didnt come with the damper so I looked up the part for a 289 from a 68 falcon (thats the motor I ordered) and put it on the motor. Will I have any problems using it (I believe it was the 28oz damper)? Pm glad I ran into this before I got to far that would bite if I did something to mess up the new motor...

 

Wayne,

Good point about the damper possibly being modded during the balancing procedure. I've spent much of my time (and money) working with a very sharp machinist that never adds or subtracts weight from flywheels, flexplates, or dampers. He always just works his magic on the crankshaft for this very reason - external parts get changed. The only other thing he ever adds or subtracts weight from is a clutch pressure plate. He balances the rest of the rotating assembly without the clutch and then adds it in so that any detected imbalance is known to be in the pressure plate. He does this for the same reason - the clutch will at some point probably get changed. I'm under the impression that many machinists use this method, but unless you know for sure that no weight has been added to or removed from the damper, it's probably best to assume that is has.

Tardster,

289's all ran a 28 oz. imbalance. The damper you got will be fine. For that matter, the only SBF dampers that would cause you a problem would be off of 1982 and newer 302/5.0L engines. The 5.0L crankshaft was redesigned for a 50 oz. imbalance in '82. All other SBF's were 28 oz.

 

Here's a good article...... has a pic of the difference between 28 and 50 oz dampers

Eaton Balancing Engine Balancing, Part 2

 

Good artical, but now that leads me to another question. I was told the flywheel off my inline 6 (its either a 250 or a 300) would work on the new motor but at the end of that artical it says they will all fit but are differant from each other, so basically that means i need to get a new flywheel right?

 

The 6 cyl. flywheel will bolt up, but the 6's were internally balanced and have a zero or neutral balance flywheel. You need one from a small block V8 with 28 oz. imbalance.

 

Dang....lol I was hoping to save the 300 bucks and use it for other stuff. Can I just order a flywheel for a 68, 289, ford falcon flywheel or will i need to add the "with 28 oz imbalance" part to it?

 

Go figure, everywhere I looked the fly wheels were 300-ish. I check out autozone again and they have them now for 50 bucks...lol

 

Just for clarification purposes, you're talking about two different families of Ford sixes from this era, what is essentially a small block six and a big block six. It's doubtful too many parts would interchange between them. You might want to do more research to know exactly what you have.

 

FWIW, if you have a driveline/engine shop in the area, you could bring them the 300 flywheel, and have them add the 28oz weight. Better yet, if there's a reputable engine balancer specialist in the area. Fortunately, I know one in Duluth.

 

How many bell housing bolt holes does the 289 have, five or six?

This will make a difference which flywheel & harmonic balancer is used.

You cannot rely on Auto-Zone selling you a supposed 1968 289, count the holes.

Before 8/23/1964: Five / From 8/23/1964 thru 1968: Six. No 289's after 1968.

C5AZ6316B .. Harmonic Balancer / Marked: C4AE-6316-C or C4AE-6316-D

Fits: 1965 289 2V/4V from 8/23/1964 except 289 HiPo, 1966/68 289 2V/4V except 289 HiPo.

When you say "flywheel" what transmission does it have A/T or M/T?

You have to use a flywheel that matches the harmonic balancer, otherwise you'll have a vibration that will...sooner or later, tear the center section oughtta the flywheel.

EDIT I-6: The 200 flywheel is different from a 250. The 240/300 flywheel is not the same as either. None are the same as 289!

 

The block has 6 holes where the tranny bolts up at. The numbers off the block on the very bottom pass side is 0 05AE-6015E if that helps. And the tranny is a C4 auto.

 

C3AZ6375L .. Flywheel (Flexplate) 157 teeth / Use with C4 transmission / Obsolete

Fits: 1963/68 289 / 1968/76 302.

This should be EZ to find at autoparts stores, but if you want a gen-u-ine Ford original, I found dozens of them at FoMoCo Dealers, obsolete parts vendors.

The last MSRP was $245.83, dealer net cost was $147.50. Because the part is obsolete, the dealers can no longer return it to Ford, so are STUCK with it.

DON SANDERSON FORD in Glendale AZ has THREE (623-842-8762) and usually sells obsolete parts at below their original net cost.
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There is another flexplate that has 164 teeth. It was used in full sized Fords with 289's and FX Cruise-O-Matic, and on 1978/80 302's.

> > Note the edited in info regarding I-6 flywheels in post #13. < <