TampaRiv

Harmonic Balancer, what's the deal?

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Don't forget that 1/4" thick special washer or you'll be up the creek in no time.

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64 Riviera. So....In my infinite brilliance. Replaced the timing chain, cover, water pump. Went to reinstall the harmonic balancer and the keyway is worn. Im not so much worried about the pulley boss although it might affect balance slightly. Of course it it reassembled now. The key is slightly worn and of course I didnt address it while it was off. Think I can run it as is? How would I even try to fix it? Weld it up and recut the keyway?

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   Dont run that...it will loosen up. Easiest, and probably least expensive pathway is to find a replacement

Tom Mooney

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That pulley is JUNK.  You can see the elongation of the keyway, the broken external part where the fan belt pulley rides.

You can see in the photo only one balance pin, may be more.  Can also see the drill marks for the critical fine balance.

I can see 5 drill indentations, may be more. All I can see in pics.

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Forgot. You must closely inspect the snout of the crank ALSO in that area as well as the key itself.

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               If that balancer hasn't ruined the crankshaft already it soon will.........don't drive it anymore till you tear it down, inspect the crank

snout and key and replace with a good balancer.

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Final Trim Balance Specific for each engine is done on the harmonic balancer AND the Flexplate? I've noticed that on other engines and thought it was a static trim for the flexplate only. What about the Dynaflow, no ring? In the Nailhead's case, the Flexplate stamping includes the external offset balance. So, the way I see it, the crankshaft along with both the harmonic balancer and the flexplate are dynamically balanced before engine assembly. No trim balance.

 

Although harmonic balancers and flexplates can be replaced, they wouldn't include that dynamic balance of the 3 components specific for that engine. Further more, used parts would include a balance specific for another engine. Not a huge difference, but not dead-on as when new. I imagine if we could go to the GM Parts Counter and order a new balancer, it would have a static balance for that item only (including the offset that the Nailhead requires).

 

I purchased a Flexplate from Centerville Auto Repair with a chunk of sheet steel tacked on for the external balance. When I asked what the balance process was, thinking the offset was added after a static balance, he blurted out "we never had one come back"!

 

Anyway, my head hurts!

Keep at those Harmonic Balancers until you get it right. No catastrophic failures!

John B.

 

 

 

 

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I just checked 1963 and 64 Shop manuals sections 2-11 and 2-27. Not much in the 64 but the 63 manual claims a dynamic balance upon assembly and a final balance when in operation. It shows an image of adding weights  to the Dynaflow torque converter for the final balance.

Section 2-27:  "Completely assembled engines are also given a running test and balanced to very close limits by drilling the flywheel or by adjusting converter balance weights as required".   Also, an underlined Note stating a trimmed torque converter cannot be used with another engine. So remove all weights especially when a previous repair did not mark the orientation on disassembly? Flexplates use weight removal instead of weight addition as on the Dynaflow.

So a test drive is a must with Harmonic Balancer and Flexplate/Torque Converter replacement!

 

John B.

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15 hours ago, XframeFX said:

I just checked 1963 and 64 Shop manuals sections 2-11 and 2-27. Not much in the 64 but the 63 manual claims a dynamic balance upon assembly and a final balance when in operation. It shows an image of adding weights  to the Dynaflow torque converter for the final balance.

Section 2-27:  "Completely assembled engines are also given a running test and balanced to very close limits by drilling the flywheel or by adjusting converter balance weights as required".   Also, an underlined Note stating a trimmed torque converter cannot be used with another engine. So remove all weights especially when a previous repair did not mark the orientation on disassembly? Flexplates use weight removal instead of weight addition as on the Dynaflow.

So a test drive is a must with Harmonic Balancer and Flexplate/Torque Converter replacement!

 

John B.

Sometimes fixing a 50 plus year old car....or any machine after original manufacture...deviates somewhat from perfection.

Tom

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I've been saying it for a long time now about the factory balance.  No two are alike that's why I ask for pictures of the old balancer BEFORE I send a used replacement balancer so I can compare the pins & drilled holes.

With that said so far there have been no negatives that I'm aware of. They ALL appear to be/run smoothly.

How much of a difference does it really make??? Who knows???  BUT I would imagine it would be in the upper RPM ranges which is probably above what most/many will do anyway.

In stock form I have & do run my 425 "Nail" to 5200-5400 RPM's even when it was new & narry had any problems.

Then again when I rebuilt the engine in the very early 70's & the assembly was balanced & additional drilling was nec. to bring EVERYTHING in balance including the balancer & flexplate.

AND, there's no way the harmonic balancer, or flexplate, can be "Matched" balanced to the originals WITHOUT the assembly, rods, pistons, crank, etc.  You may get close, BUT that's only counts & true in horseshoes.

Just my take on the subject at hand.

 

Tom T.

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Closeness counts in the 3 "H's":  horseshoes, hugs, and hand grenades.  Maybe we could add a 4th - harmonic balancing.

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Yeah Ed I was trying to think of the extra add on's & had a senior moment where I couldn't think of anything else.

It's rough gettin' old.

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So, on the harmonic damper, I noticed Centerville Auto Repair Site recommends center-punching a mark on the hub where the keyway is when it is off the crankshaft. This way it can be compared in relation to the timing mark on the ring when installed.

 

My nailhead idles rough but I attribute it to a missing torque convertor bolt! My 1988 receipt for Dynaflow repair states stripped threads in the 3rd hole. They were fine when I installed it where it failed shortly after and had to be pulled again. Those clowns also broke my turn signal cable man-handling my disabled Riv out of their service bay.

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Give me a couple Vee blocks and an electric motor with a pulley that matches your belt size and I'll get you pretty close on the crank assembly.

 

Give me a bigger motor, pull the plugs, and I'll do the whole assembled engine . 1750 or 3500 rpm.

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John B,

 

   I think your miss understanding what Russ said.  You put a punch mark on the hub & the outer ring to see IF the outer ring has moved. IF it has the ignition timing can't be set properly.

On the missing converter bolt??? (I remember it to be a nut) should not cause a vibration at idle., IF it was the vibration would get worse as engine speed (RPM's) increased. Read what you mentioned & re-furred to via section 2-27.

 

 

I used to have a wheel balancer that used a strobe light for balancing tires on the car.  I successfully used it to balance a WAY out of balance engines a few times after a re-build.

Made it smooth, BUT I couldn't tell you IF it was balanced properly.

 

Bernie that would be interesting to see & witness being done.

 

Tom T.

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