JL_94z28

iTrader: (6)

When my 383 was assembled by a professional race shop, the rotating assembly was internally balanced & blue printed. I also provided the builder a brand new Fidanza flywheel and a BBK under drive pulley, both of which were zero balanced. The under drive pulley bolts directly to the hub.... since everything is balanced, is there any need to run a balancer? The builder told me no, that since the motor was internally balanced, and both the flywheel and pulley were zero balanced, it wasn't necessary. Just curious if anyone else is doing something similar?? Here's a link to the BBK pulley I'm running:

http://www.bbkperformance.com/produc...lley-kits.html

BIGCAT7274

Yes you need to run it.
http://www.atiracing.com/products/dampers/101/index.htm

cardo0

Yes u need to run a "dampner". The dampner is often miscalled a balancer but it does nothing to balance the engine on our zero balanced LT1s. But even on the older external balanced sbc engines its real name is a "dampner".

The dampner has some elastomer that helps reduce the uneven pulses on the crankshaft. U can see some elastomer sandwiched in a ring around the dampner.

Dont forget your dampner,
cardo

JL_94z28

iTrader: (6)

Thanks! I thought so!!! Summit Racing should send you a commission. LOL!

Going with the aluminum ATI balancer:

http://www.summitracing.com/parts/at...ro?prefilter=1

BALLSS

you can buy a 10% underdrive ATI "damper" for the LT1

cardo0

JL, why do u need a $370 dampner? Are u racing in a bracket higher than stock? Is that ATI even SFI certified - i dont see it on that link u gave? That $370 dampner wont make your car go any faster. Try rock auto, they have a LT1 "zero balanced" dampner for only 60 bucks.

Good luck,
cardo

JL_94z28

iTrader: (6)

Gotta break myself of using the wrong term! Went to ATI's website, and found this damper for the LT4 vette's - it comes in at 6.78" (assuming that accounts for the 10% underdrive) instead of 7.5" LT1 version.

http://www.summitracing.com/parts/at...3/applications

JL_94z28

iTrader: (6)

Ya, I built this motor to race. Every thing put in to it has been race inspired, right down to weight reductions.

noice

The harmonic balancer is just that. It keeps the crankshaft from vibrating in torsion. Left unchecked a you will kill the motor or hurt bearings.

ahritchie

iTrader: (1)

The ATI one is very nice, very expensive though. Whatever you do don' t buy any Professional Products Chinese garbage balancers....ask why I know!

If you want an affordable well built one, I highly recommend the JEGS brand one for LT1's...you can get it 10% underdrive too. It's actually a Powerbond Aulstralian peice which is quite well made for the low price; it's good for 12,500 RPM. My 383 now has one and it works great!

http://www.jegs.com/i/JEGS-Performan...oductId=757291

JL_94z28

iTrader: (6)

Cool, appreciate the feedback! I assume you had a bad experience by that statement!! I did go with the 10% underdriven version from ATI. Spent some time talking with there tech team, very friendly and knowledgeable. Felt comfortable and confident with the product I was buying. Arrived at my doorstep today! I know where I'll be tonight!

ahritchie

iTrader: (1)

You might say that....this is what happens to Chinese **** driving down the road at 2000 RPM:

JL_94z28

iTrader: (6)

That's no good!!! Hopefully it didn't damage anything else upon going in to selfdistruct mode!

pboxfun

iTrader: (2)

Anyone using Auto Specialties Harmonic Balancer ASP945100? Says it's SFI approved.
http://www.summitracing.com/parts/asp-945100

BALLSS

yes, mine is

see pic on link http://www.jegs.com/i/ATI/085/917274...FcU5QgodZjAABw

PA94Z

iTrader: (1)

You amaze me sometimes with what you say.. The ATI unit is SFI 18:1 approved. It is the best damper you can buy for a car. Crank harmonics are harmful to the engine and performance. The crank drives the cam, and harmonics get transferred to the valve train. Harmonics in the valve train cost power.. and reliability. Innovaters West make a very nice damper also. With that said.. I run both damper and flex plate by ATI,

96TransAmboosted

iTrader: (8)

any time we build an engine that not a stock replacement we go with a 1 piece damper, we have had multiple cars with ac still brake 2 piece balancers within 5k miles some do damage some are caught before they can. i personally broke 3 or 4 before we finally found a unit that worked perfect, it was a fluidamper, very nice units for performance aplications