Harmonic balancer should run true, correct??

[Timbers]

I have had March underdrive pulleys on my car now for about 6 years. I noticed something the other day that I never noticed before:

The harmonic balancer has a slight wobble to it while the engine is idling. The aluminum underdrive pulley underneith it runs perfectly true, almost looks like it isn't even spinning its so true, but the harmonic balancer has a slight out of round look to it when it spins. If I rev the engine up it kind of goes away, but it could be an illusion.

I don't know how I could possibly have installed it wrong, all you do is slide it on and tighten the bolts up right? Is there some sort of alingment technique that I didn't do, that is causing this to wobble?

Thanks for the info!

...Tim

[DeWynter]

Well due to the fact that there is no info on the engine or year Im gona take a stab in the dark. If its a traditional balancer with a ring mounted on rubber, they sometimes slip and start to wobble, by slip I mean the outside ring moves independent of the inside ring or the part that actually is bolted to the crank. if its a fluid filled one, its bad machining, or it could be bad machining on any balancer. The thing I would do is get a new factory one for cheap, or goto a fluid filled one for a bit more money.

[Timbers]

Sorry

I have a 97 TransAm. So the LT1 engine. You put the March pulley on, then bolt the stock balancer back on top of the underdrive pulley.

Get a nice fluid filled one huh? I could probably do that. I know am out of round one can't be good!!! Probably wreck a crank bearing after awhile I would assume.

Thanks for the info.

...Tim

[Injuneer]

There are a lot of people who will tell you to shy away from the Fluidampr.... and at $400 a pop its a serious decision.

Typical problem is dry rot of the rubber ring on the stock damper, that holds the inner and outer rings of the damper together. Another possibility with your add-on pulley is that the damper isn't seated correctly, or the bolts are coming loose. Have you checked them?

There are some relatively low $$$ replacements available.... The SFI-rated dampers for the LT1 approach $400 each, and aren't really necessary unless you need to pass NHRA tech or are winding the engine to some really high rpm level. In any case, I would replace it to protect the crank.

[DeWynter]

I've never had to buy a damper for a LT1, but I wouldn't think them to be that much more expensive than one for a gen 1 sbc, I could be wrong
I bought a new fluid damper for my 383 off of ebay from a dealer and got it for about 100 Canadian. The factory replacement was a wopping 35-60 Canadian . not bad but still for the extra money I went with a damper that works well at all RPMs not just some better than others. I have seen SFI certified dampers on ebay also for around 100 dollars Canadian, also for a Gen 1 sbc.

[Injuneer]

I've never had to buy a damper for a LT1, but I wouldn't think them to be that much more expensive than one for a gen 1 sbc, I could be wrong
I bought a new fluid damper for my 383 off of ebay from a dealer and got it for about 100 Canadian. The factory replacement was a wopping 35-60 Canadian . not bad but still for the extra money I went with a damper that works well at all RPMs not just some better than others. I have seen SFI certified dampers on ebay also for around 100 dollars Canadian, also for a Gen 1 sbc.

You are wrong. Both the ATI Super Damper and the Fluidampr for the LT1 serpentine belt system ar near $400. I have the ATI. It was $385 4 years ago. Even the "standard" dampers for the LT1 are expensive, because of the serpentine belt requirements.

Not sure why you feel you have to challenge virtually every fact anyone posts about the 4th Gen cars, based on your 3rd Gen experience. They are two fairly different cars.

[DeWynter]

I’m sorry I don’t mean to "challenge" everything with my knowledge of third gen cars especially when they are "facts", but in most respects prices of parts are very similar across all SB engines and most things in a third gen are at the very least very similar in design in the driveline and rear suspension. I was using ebay as a price guide because a much better deal can be made through that than through a regular outlet store, but if its a real problem I just wont post. I feel these when bought now are hardly $400
http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW
http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW
http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW
http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW

And for a strait factory replacement style non sfi
http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW

ALL of these prices are within $40 dollars of the SBC gen 1 style, also found on ebay.

I have no problem with "facts" its just that I saw them cheaper and thought I would say so, I also posted specifically that it was ebay.

[Injuneer]

A couple of points..... and then I'll leave this thread alone, since its obvious I'll never convince you the LT1 is not the same as you Gen 1 SBC.

I have to admit, I'm not familiar with the products you found on e-Bay, but it appears from your comments, that in every case the LT1 part costs more than the SBC1 part. In fact, I've never seen anyone use a "Professional Products" damper, so I have no way of knowing if it is a good quality product. The fact that it is sold on e-Bay doens't make it one. Notice also, that the "Fluid Damper" they are selling is not a real "Fluidampr" made item, its a "replica" as best. Again, maybe its a quality product, but I don't know anyone who has used them.

A few items from the Summit and JEG's catalogs:

Pioneer Harmonic Damper:
SBC internal balance - $85
LT1 internal balance - $116

ATI Super Damper:
SBC steel internal balance - $260
LT1 aluminum internal balance - $400

Fluidampr "tm":
SBC internal balance - $268
LT1 internal balance - $370

"JEG's" SFI:
SBC - $190
LT1 - $209 + $80-90 for hub

Just curious.... have you ever actully looked closely at an LT1?

[DeWynter]

A couple of points..... and then I'll leave this thread alone, since its obvious I'll never convince you the LT1 is not the same as you Gen 1 SBC.

Well for one im not arguing that they are the same, never did I say that they are the "Same Part" and yes I have seen many LT1s, yes there are differences, and simularities. Some parts are the same,( oil pump ) others are not( intake, heads, distributer/spark system ) we all know this and many parts from an LT1 will swap over to a gen 1 sbc with some "modification" ( heads, intake etc.) You dont know me nor do you know my background and or technical skills. I will re phrase what I said in an earlier post, which is probably where you got the notion that I thought the engines are the same. Most parts for the LT1 are of comparable price to the same "type" of part on a sbc gen 1 (not the same part or part number) I would imagine any part that is truly SFI certified will do as it is a strict process of testing and needs to meet certin standards, I didnt say I was getting prices of top of the line parts from the biggest names in parts. I find your last post very derogitory, especially from a moderator. Everyone here is at a different state of knowledge. I dont claim too know everything, but suggesting ive never seen an LT is quite a step, especially for someone who is supposed to be setting an example for others to follow. I have had quite a bit of time to play with the LT1 even though I dont own one. I may live in Canada, but we have cars here too.