badazz81z28

iTrader: (6)

Anyone know why there is not really a harmonic balancer on LS engines as compared to a SBC/BBC?

Mike454SS

iTrader: (4)

It's built into the crank pulley.

96 Comp T/A

iTrader: (8)

Well, none of them were really balancers unless you are talking about 400 SBC, or Fords which were externally balanced with extra material on one side of it. It really a damper or dampener, and the LS1's do have a damper . There is a bonded rubber substrate between the hub and the pulley. Why that is so much smaller less noticeable than previous iterations is probably down to the advancements in technology. It also probably has something to do with the long rubber band attached to it driving the water, alternator and power steering pumps.

badazz81z28

iTrader: (6)

I have been reading up a lot on under drive pulleys, seems the biggest item discussed is how an ATI is the best way to go, but what would make the stock or powerbond pulley so inferior? People are discussing broken timing chains etc because they "harmonic balancers" are not really dampening harmonics.

96 Comp T/A

iTrader: (8)

Materials, and weight of the damper. It's a pretty advanced topic, (beyond the scope of my knowledge anyway) but the hardness and thickness of the rubber (or whatever damping material the manufacturers choose to use, and the weight of the outer ring are all critical components to the equation for a given combination. That takes R&D, precision measuring equipment and lots of know how. Companies like ATI and Fluidampr have lots of both. I can't speak for the other aftermarket companies, because I have never had their products, but if it is properly engineered for an application, I don't see anything wrong with using them. What I do have a problem with are inferior copycat products that end up using different (cheaper) materials and the quality of the dampening suffers. You get what you pay for! As far as the stock one goes. The rubber used in the ring is crap. It's pretty common occurrence for garage queen Corvettes to flip the belt off after sitting for a while then starting because the tension of the belt has pulled the damper off center just enough to cause it to run untrue. It happened to my father's vette, he had it towed to the dealership, he was expecting a week to get the parts, and they had 3 on the shelf. Service writer said it happens all the time to cars that sit. (In my dad's case 9 months while he was building a new house).

badazz81z28

iTrader: (6)

What have you heard/know about the SLP/PowerBond Pulleys?

01ssreda4

iTrader: (96)

Only time timing chains are breaking is in road race type applications where certain rpms (frequency) are being held for extended amounts of time. They rarely if ever break in drag type applications.

redbird555

iTrader: (14)

^this in road racing where rpms are held high the harmonica on the chain tend to destroy it much faster. Couple that with the fact you are now decreasing the "dampening" on the crank by 25% and you begin to see the issue.

With that said I wouldn't hesitate to run a powerbond/slp if I just dd it and tracked on weekends. The only reason I run an ati is because of a stupid good deal I got on a scratch and dent one

studderin

iTrader: (28)

ya its not just rpm, the load on the motor causes weird things ( 1st noticed is timming change failure) but the whole valvetrain gets beat up. Road race guys see it if you damage the trans or somthing else that forces the driver put the engine is some non normal situations

AmarilloWS6

iTrader: (3)

I've had nothing but great luck with both of my Powerbond 25% underdrive pulleys. I had one on my WS6 and have one on my C5 now. On both cars the throttle response was much improved, my steering never changed, my temps never changed, my voltage never changed, etc. Both of my cars were tuned with the pulley on so it was accounted for in the tune as well. Both of those cars were/are daily drivers and while I do take great care of my cars, I still frequently have "fun" with them if you know what I mean I'd say go for it! It only takes a couple of minutes on an F-Body.