Harmonic balancer... what to get?
Thread Starter
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Harmonic balancer... what to get?
Well, I have an engine vibration/shake from idle to 2500. I _THINK_ it might
be the balancer. It does it in neutral and going down the road.
So since the balancer is over 30 years old I figure even if its not the
problem it is time to replace.
So my question: Is there any reason at all to go with anything but stock or
stock replacement? I find fluidampers and the other guys claims suspicious.
This is a street car that sees a max of 6000 rpm (454, massive torque).
What are your thoughts? Looks like a stock replacement is $65. GM is $120
and the aftermarket fancy stuff is atleast $260 upto over $300.
/Markus
be the balancer. It does it in neutral and going down the road.
So since the balancer is over 30 years old I figure even if its not the
problem it is time to replace.
So my question: Is there any reason at all to go with anything but stock or
stock replacement? I find fluidampers and the other guys claims suspicious.
This is a street car that sees a max of 6000 rpm (454, massive torque).
What are your thoughts? Looks like a stock replacement is $65. GM is $120
and the aftermarket fancy stuff is atleast $260 upto over $300.
/Markus
Le Mans Master
Joined: Jul 1999
Posts: 9,206
Likes: 17
From: Sewell NJ
Re: Harmonic balancer... what to get? (zwede)
I replaced mine with a GM balancer that I got from Pace. For the kind of driving I do it's just fine. The only reason I would put a more expensive balancer on is if I raced it regularly and wanted an SFI certified balancer. I would consider it a safety measure then. I guess if you're going to spin the engine past 6500 a little margin of increased safety is a good idea. I remember when I was a kid in the musclecar heyday how many cars were raced every night with nothing more than a scattershield and I don't recall any balancers giving up the ghost. I would recommend, if you are going to change tha balancer, to get a proform balancer cover like the one I have. It makes setting the timing curve a snap and it's cheap and looks good too.
Safety Car
Joined: Jun 2002
Posts: 4,844
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From: Pearland TX
St. Jude Contributor
Re: Harmonic balancer... what to get? (zwede)
zwede,
If you decide to go to an aftermarket balancer be sure and think about the spacing(thickness) of it. You could very easily throw off the alignment of all of your pulleys. The aftermarket balancer I have on this engine was a good 1/8" shallower than the stock one. Balancers like Fluiddamper are not designed to have some clod pulley ruining what they put together although they will give you the bolt holes(threads) to do it.
If you decide to go to an aftermarket balancer be sure and think about the spacing(thickness) of it. You could very easily throw off the alignment of all of your pulleys. The aftermarket balancer I have on this engine was a good 1/8" shallower than the stock one. Balancers like Fluiddamper are not designed to have some clod pulley ruining what they put together although they will give you the bolt holes(threads) to do it.
Thread Starter
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Re: Harmonic balancer... what to get? (vettfixr)
I would recommend, if you are going to change tha balancer, to get a proform balancer cover like the one I have. It makes setting the timing curve a snap and it's cheap and looks good too.
I'm leaning away from the aftermarket stuff. The little info I've found online doesn't even show rpms below 5500. Looks like they are for 6000 rpm and up.
Now should I pay the premium for the GM stamp or go with an OEM replacement... hmmmm.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Re: Harmonic balancer... what to get? (zwede)
I doubt the dampner would shake the whole car man. Mine separated from dry rot and only squeled and rang alot. Bought a Streetdampner by fluidampner for ~$160 (Summit) and painted myself. But no Streetdampner's for BB - only ~$350 SFI fluidampner for the BB. :( . I've read the liquid filled are best against vibration and no rubber/elastomer to wear/rot out. Should be able to use engine after engine (cheap sleeving repair maybe). Liquid filled types dampen timing set vibration which inturn makes more power - or should say loses less power with more accurate valve train timing.
Now I did find an off brand at PAW for the BB at ~$130 and SFI approved too. PAW phone #818-678-3000 but no on-line catalog. They sell a monster 1200 page catalog for only ~$4 (with purchase) and it's a fantastic reference parts book for the motor head. :yesnod: That part number is PAW-FB427 and is a 6&1/4" dampner for internal balanced motors. :chevy
Now I did find an off brand at PAW for the BB at ~$130 and SFI approved too. PAW phone #818-678-3000 but no on-line catalog. They sell a monster 1200 page catalog for only ~$4 (with purchase) and it's a fantastic reference parts book for the motor head. :yesnod: That part number is PAW-FB427 and is a 6&1/4" dampner for internal balanced motors. :chevy
Drifting
Joined: Oct 2000
Posts: 1,825
Likes: 56
From: Shawano WI
Re: Harmonic balancer... what to get? (cardo0)
I a balancer on an internal balanced motor slips it will not vibrate but if a balancer on an externaly balanced motor slips it will vibrate a lot.
Fluiddampners are all hype and not worth the money and certainly will not make more power. A GM or quality replacement (not tiawan or china) is your best bet.
Fluiddampners are all hype and not worth the money and certainly will not make more power. A GM or quality replacement (not tiawan or china) is your best bet.
Thread Starter
Race Director
Joined: Sep 1999
Posts: 11,361
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From: Plano TX
Re: Harmonic balancer... what to get? (Pete79L82)
I'm trying to remember how the balancer is designed... For an externaly balanced engine, where is the counterweight? Is it on the center piece of the balancer or is it on the outer ring? If it's on the center I guess the outer ring slipping wouldn't cause much of an imbalance?
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Melting Slicks
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
Re: Harmonic balancer... what to get? (zwede)
...For an externaly balanced engine, where is the counterweight? ...
EDIT>>> :smash: After pressing the "send" button I remembered that the GM O.E. style balancer is as I described but my new balancer does actually have a seperate weight bolted to the inside of the balancer. I'll send or post a pic.
[Modified by MIKER, 8:54 AM 6/3/2003]
Race Director
Joined: Mar 2001
Posts: 11,322
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From: Living in the Hartland
Re: Harmonic balancer... what to get? (zwede)
I'm trying to remember how the balancer is designed... For an externaly balanced engine, where is the counterweight? Is it on the center piece of the balancer or is it on the outer ring? If it's on the center I guess the outer ring slipping wouldn't cause much of an imbalance?
Melting Slicks
Joined: Oct 1999
Posts: 2,581
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From: Tolar Texas
Re: Harmonic balancer... what to get? (MIKER)
For visual reference, here are pictures of the old and new balancers (harmonic dampers) for my externally balanced 388 sbc.
Stock sbc 400 balancer:
Replacement sbc balancer purchased from Summit Racing: ($70)
Summit lists a Chevy 454 harmonic damper (ext. bal.) for $80.
Stock sbc 400 balancer:
Replacement sbc balancer purchased from Summit Racing: ($70)
Summit lists a Chevy 454 harmonic damper (ext. bal.) for $80.
Thread Starter
Race Director
Joined: Sep 1999
Posts: 11,361
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From: Plano TX
Re: Harmonic balancer... what to get? (MIKER)
OK, so if a stock external balanced balancer slips, major vibration commences... I'll go see if I can pick up a new balancer at lunch.
I did some more tests. Slowly revving in neutral it is smooth to 1200. Slight shake at 1300-1400. Right at 1600-1700 there's a spot where the whole car shakes. Above that it gets better again. I don't hear any missing during this (exhaust sound is smooth), so I'm thinking it must be an imbalance.
I did some more tests. Slowly revving in neutral it is smooth to 1200. Slight shake at 1300-1400. Right at 1600-1700 there's a spot where the whole car shakes. Above that it gets better again. I don't hear any missing during this (exhaust sound is smooth), so I'm thinking it must be an imbalance.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Re: Harmonic balancer... what to get? (zwede)
I too think the fluid damper stuff is more hype than not. I too believe an elastomer type damper similar/like the stock one is best bet. Pioneer makes very good OE and SFI-approved ones. Pioneer can be had through most auto parts stores ... contact me if you can't find a nearby source. Currently, Pioneer dampers are made in Australia. The absolute finest in these type dampers are made by BHJ in California USA. I also have some very nice machine shop tooling BHJ manufactured http://www.bhjinc.com/
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Re: Harmonic balancer... what to get? (Pete79L82)
I a balancer on an internal balanced motor slips it will not vibrate but if a balancer on an externaly balanced motor slips it will vibrate a lot.
Le Mans Master
Joined: May 2000
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From: Bloomington MN
Cruise-In II Veteran
Re: Harmonic balancer... what to get? (jackson)
I am on my third elastomer type balancer in three years. One 30 year old stock piece (came on my car), one brand new Proform, and one used 72 GM piece. Every one of them slipped the outer ring after I ran them. It didn't slip in or out, it slipped around the inner piece, throwing the timing mark off (WAY off with the original balancer). The first time, it took me a very long time to figure out why it ran like crap when I timed it off the balancer. There was no vibration, it just threw the timing mark off. I am going to go with a Fluiddamper Streetdamper next time, as there is no way to mess that one up.
AC
AC
Drifting
Joined: Oct 2000
Posts: 1,825
Likes: 56
From: Shawano WI
Re: Harmonic balancer... what to get? (jackson)
I a balancer on an internal balanced motor slips it will not vibrate but if a balancer on an externaly balanced motor slips it will vibrate a lot.
With all due respect, I disagree. External dampers have a counterweight ... but all sbc & BBC dampers (regardless internal or external) are balanced via machined depressions in outer ring. Although an external motor needs an external damper, the damper does not actively balance the motor ... it dampens crank twist. Same goes for internal motors. However, if the outer ring slips a vibration will ensue ... internal or external. Otherwise, I agree on damper sources/designs.
With all due respect, I disagree. External dampers have a counterweight ... but all sbc & BBC dampers (regardless internal or external) are balanced via machined depressions in outer ring. Although an external motor needs an external damper, the damper does not actively balance the motor ... it dampens crank twist. Same goes for internal motors. However, if the outer ring slips a vibration will ensue ... internal or external. Otherwise, I agree on damper sources/designs.
That is incorrect. On an external balanced motor the balancer is used to balanced the motor not just a vibration dampner. An internal balanced motor may have some holes drilled into the outer ring to bring it to nuetral balance but nothing like the large depression on an external balanced dampner. With the large depression if it slips it puts the motor severly out of balance. With an nuetral balanced dampner it it slips the out of balance condition is minor and may only have a slight vibration.
Pete
Thread Starter
Race Director
Joined: Sep 1999
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From: Plano TX
Re: Harmonic balancer... what to get? (zwede)
Well, I went to NAPA and looked at their balancer. It actually looked very nice. All machining was done great. It even had 10 ATDC to 60 BTDC etched into it. Downside was made in China, but I'm finding pretty much any steel piece nowadays originates in china. :rolleyes:
Anyway, at $64 it was too good to pass up so I got it. Probably install it tomorrow.
As for the balancing: The new one looks just like the original GM piece. The inner ring (attached to the crankshaft) has the main counter weight. The outer ring is perfectly neutrally balanced (no protruding pieces) EXCEPT it has several holes drilled into one side only.
So conclusion is that if the ring slips, it will have an imbalance. I'll know for sure when I take the old one off and look at them side by side.
Anyway, at $64 it was too good to pass up so I got it. Probably install it tomorrow.
As for the balancing: The new one looks just like the original GM piece. The inner ring (attached to the crankshaft) has the main counter weight. The outer ring is perfectly neutrally balanced (no protruding pieces) EXCEPT it has several holes drilled into one side only.
So conclusion is that if the ring slips, it will have an imbalance. I'll know for sure when I take the old one off and look at them side by side.
Thread Starter
Race Director
Joined: Sep 1999
Posts: 11,361
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From: Plano TX
Re: Harmonic balancer... what to get? (zwede)
BTW: The new balancer looks just like the picture Miker posted of the new aftermarket one he picked up. Only difference is my counter-weight doesn't bolt on.
Race Director
Joined: Mar 2001
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From: Living in the Hartland
Re: Harmonic balancer... what to get? (Pete79L82)
I a balancer on an internal balanced motor slips it will not vibrate but if a balancer on an externaly balanced motor slips it will vibrate a lot.
With all due respect, I disagree. External dampers have a counterweight ... but all sbc & BBC dampers (regardless internal or external) are balanced via machined depressions in outer ring. Although an external motor needs an external damper, the damper does not actively balance the motor ... it dampens crank twist. Same goes for internal motors. However, if the outer ring slips a vibration will ensue ... internal or external. Otherwise, I agree on damper sources/designs.
That is incorrect. On an external balanced motor the balancer is used to balanced the motor not just a vibration dampner. An internal balanced motor may have some holes drilled into the outer ring to bring it to nuetral balance but nothing like the large depression on an external balanced dampner. With the large depression if it slips it puts the motor severly out of balance. With an nuetral balanced dampner it it slips the out of balance condition is minor and may only have a slight vibration.
Pete
With all due respect, I disagree. External dampers have a counterweight ... but all sbc & BBC dampers (regardless internal or external) are balanced via machined depressions in outer ring. Although an external motor needs an external damper, the damper does not actively balance the motor ... it dampens crank twist. Same goes for internal motors. However, if the outer ring slips a vibration will ensue ... internal or external. Otherwise, I agree on damper sources/designs.
That is incorrect. On an external balanced motor the balancer is used to balanced the motor not just a vibration dampner. An internal balanced motor may have some holes drilled into the outer ring to bring it to nuetral balance but nothing like the large depression on an external balanced dampner. With the large depression if it slips it puts the motor severly out of balance. With an nuetral balanced dampner it it slips the out of balance condition is minor and may only have a slight vibration.
Pete