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View Full Version : Performance differences in Harmonic Balancers?



syphon
04-26-2003, 07:48 PM
I'm looking at getting a new harmonic balancer, as I'm trying to drill the broken pulley bolts out of my current one and it's not working out for me.

I'm considering getting the HB setup found on Supercoupeperformance.com but at $360 that's quite a pretty penny. I'm wondering what performance gains, if any, that will gain me over buying another stock one? (does anyone know where I can get a stock one anyway?)

What all is part of putting a new one in? It says I have to bolt my crank sensor to the new balancer, and that the pulley needs to be zero-balanced. Does the pulley need to be balanced if I just put in a new stock one? How much would a mechanic charge to do all this work? I'm thinking this is way over my head here.

pastera
04-26-2003, 08:58 PM
You won't see a performance gain with the BHJ balancer. It is actually heavier, so you would see a very slight decrease in performance if used with the stock pulley. The gain is in reliability, the BHJ won't break like the stock unit will.

You can get a stock unit from ford for about $200. This is the balancer and pulley together. It is very easy to install if you have a balancer install tool (mine is out on loan at the moment).

If you do the work your self, you can be done in four hours and it will cost you about $220 total. You will need a new balancer assembly, crank bolt, washer,front seal (should be replaced) and a tube of antisieze compound and thread locker (locktite). Special tools are a balancer removal/install tool for metric threads and a torque wrench that gos up to 100 ft-lbs.

The BHJ must be honed to match your crank snout ($30) and the pulley must be balanced ($30-$50). Otherwise you will need the same things as above.

Aaron

lessonintorque
04-26-2003, 09:00 PM
First off if you are running stock and plan to stay that way you should not have a problem with a stock balancer. They come complete with the main pulley from most ford dealers for 315$, If you have a decent grasp on mechanics and a haynes or chilton manual (17$ at most auto zones) you really can do it your self. Now second part to that answer, If you want to get decent to large hp/torque the scp balancer is excelent,i have one and its good up to mor hp than most people without a shop are gonna get. so I say if you got the extra 45$ dollars go with scp,but if you wanna stay stock ford is the way to go. If you have anymore questions personal message me, I just did the swap a week ago.

BT Motorsports
04-27-2003, 01:04 PM
Actually, depending on how much of a rush you are in, you may want to get in on this group buy which is beginning..... http://www.sccoa.com/forums/showthread.php?s=&threadid=22373
Otherwise, I have them on the shelf for less than anyone else.

Paul

kevenj90sc
04-27-2003, 01:28 PM
ok to jump into this topic, i understand having to have the pulley balanced to use the BHJ balancer, but why does it have to be honed to fit? aren't as SC cranks the same size? and if not , then wouldn't the ford unit need to be honed to fit also? I have a totally stock 90 SC with 117,000 -- no wobble or anything from the balancer area -- do i need to be concerned? Should i change the balancer as a preventive maintenance measure or am i ok with the original one on a stock engine? I have no plans to modify it, all i have done is exhaust.....

pastera
04-27-2003, 03:29 PM
The BHJ damper is designed for a 0.0015" interfernce fit. If you go over that, you run the risk of cracking the damper at the keyway. Under that and you won't grab the crank well enough to hold the damper in position (the key is only to align the damper).

The Ford unit does not need to be 'fitted' to the snout because of the Al/steel contruction - it has enough give to make up for tolerances in the crank snout. The problem is that it has so much give it stretches and gives out over time.

If you have no wobble in your damper then you are probably OK. I replaced mine because of a perceptable wobble (20-30 mil).

Aaron

RBM91
04-28-2003, 02:33 PM
Keven, If you have an original balancer at high mileage I'd for sure change the bolt. There's various opinions on this but I for one believe the bolt failure initiates the balancer failure. Bolts are cheap. After my damper failed I've gotten in the habit of changing the bolt yearly. If BHJ's were around at the time I certainly would have done that instead of another stock balancer. The stock balancer is a designed obsolescence thing. There is no way that balancer design made it thru any design review without someone realizing that they would fail. Far too obvious.

plev72
04-30-2003, 05:31 AM
Grr... that's what I get for not waiting ;-) Still have my balancer sitting in the box 'cause the car hasn't been done yet. Oh well.

Maybe I'll have better timing next time.

Paul

BlackbirdSC
05-01-2003, 11:55 AM
Originally posted by RBM91
There's various opinions on this but I for one believe the bolt failure initiates the balancer failure.

When BHJ evaluated the stock units I'd sent them, they basically laughed at the Ford design. Considering BHJ only makes dampers and they told me the damper fails then the bolt breaks, I'm going with that. The bolt is only their to keep the damper from sliding off the end of the crank. If the bolt has to hold the damper on, somethings wrong.

Oh.. and more reason why the bolt is pointless, LT1 GM V8's don't use a bolt or keyway. (or didn't for some years in the mid-90s). The press fit is all that is needed to hold it on and keep it from spinning.