LT1 Harmonic balancer issue

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Jun 13, 2022 | 07:58 PM

chalou88

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LT1 Harmonic balancer issue

Hey all. Doing a carb swap on my LT1 and I'm using the opti blockoff plate with timing tab. I went with a harmonic balancer/damper from PRW which is LT1 specific and it does not clear the tab (diameter too large). I do recall reading that a Gen I style balancer is what needs to be used, which is a smaller diameter. However the LT1 balancer doubles as the pulley whereas the "typical SBC" balancer gets the pulley bolted on to the face. Would this not screw up the belt alignment? Could somebody clear this up?

Jun 13, 2022 | 08:23 PM

SS RRR

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From: Jackstandican

I am not sure how that would work, but what I do know is if you're going to somehow make a Gen I work it's has to be neutral balanced. The LT1 engine is internally balanced in the front and externally via flywheel/flexplate in the back. Any possible way to fabricate a timing tab? I thought there were dampers for sale that had timing marks on them?

Jun 13, 2022 | 08:45 PM

chalou88

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Quote:

Originally Posted by SS RRR

I thought SBC was internally balanced like the LT1. Yes the dampers have timing marks on them. The opti blockoff plate (where tab is located) is a GM part (like the intake) so there's gotta something that'll work. I'm hoping to hear from someone who's done a carb swap, what did you do as a work around?

Jun 13, 2022 | 10:42 PM

SS RRR

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From: Jackstandican

Quote:

Originally Posted by chalou88

I thought SBC was internally balanced like the LT1.

Newp.

Quote:

what did you do as a work around?

Never did this. Still running all LT1 components on mine. Sorry. Just trying to spitball....

Jun 14, 2022 | 12:07 PM

chalou88

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Quote:

Originally Posted by SS RRR

Never did this. Still running all LT1 components on mine. Sorry. Just trying to spitball....

No worries. I forgot to realize that I asked about this last winter and got an answer. (Building now that school is out ...) Only the ATI setup is like $400...I am gonna play around when I get home. I am thinking maybe the timing tab lines up behind the damper, and not on top of it. The book has me thrown off cause it says to use SBC damper but no way will that work with LT1 accy's

Last edited by chalou88; Jun 14, 2022 at 12:16 PM.

Jun 23, 2022 | 08:36 PM

chalou88

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Ok finally getting some time to actually turn wrenches here. Damper's on and it stops short of the timing tab, so stock circumference does work (despite LT1 book claiming it doesnt)

I need to know if I install the crank bolt dry or some other method before torquing ?? Also does anyone have the torque spec for the 3 hub bolts?

Jun 23, 2022 | 09:34 PM

SS RRR

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From: Jackstandican

Quote:

Originally Posted by chalou88

Ok finally getting some time to actually turn wrenches here. Damper's on and it stops short of the timing tab, so stock circumference does work (despite LT1 book claiming it doesnt)

I need to know if I install the crank bolt dry or some other method before torqueing ?? Also does anyone have the torque spec for the 3 hub bolts?

Yes just torque the hub bolt like any other bolt. I am not sure what you mean by dry? If you mean lube the threads then absolutely not. That could hydrolock the bolt and you won't get an accurate torque reading and there is the possibility of stripping the threads. Torque specs for the hub bolt is 75ftlbs. Damper bolts are- 63ftlbs.
What LT1 book are you using? A Haynes manual has a lot of torque specs.