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FE Power Forums => FE Technical Forum => Topic started by: bluef100fe on April 17, 2013, 07:47:49 AM

Title: aftermarket harmonic dampners
Post by: bluef100fe on April 17, 2013, 07:47:49 AM
Is it true that the aftermarket sfi dampers for FE's use a different pulley bolt pattern? If so how much does a person have to slot the holes and in which direction? Or better yet can some tell me what the bolt circle measures on their aftermarket damper? Seems the stock FE pulley/damper measures about 3.065 bolt circle diameter.  TIA

Cody Ladowski
Title: Re: aftermarket harmonic dampners
Post by: jayb on April 17, 2013, 07:52:40 AM
The ATI dampers use the big block Chev pattern.  It is very, very close to the FE pattern.  On my pulleys I've usually just drilled out the holes to 7/16", and then the bolts will fit.  No big deal...
Title: Re: aftermarket harmonic dampners
Post by: bluef100fe on April 17, 2013, 09:07:49 AM
Thanks Jay... do you remember which way the extra clearance was needed? To the inside or to the outside? Thanks again..
Title: Re: aftermarket harmonic dampners
Post by: jayb on April 17, 2013, 11:11:15 AM
Pretty sure it was to the outside, the FE bolt circle was a bit smaller I think.  I will check when I am home tonight, and post a message if that is not correct.
Title: Re: aftermarket harmonic dampners
Post by: fe66comet on April 17, 2013, 12:26:36 PM
I have an ATI also, the two things I had to do is mill my crank spacer .375 to align the balancer with the original pulleys and I just purchased a Chevy pulley due to I am going  serpentine anyhow.  All the other balancers I have seen are direct bolt on like original in varying diameters from 6 to 8 inches.
Title: Re: aftermarket harmonic dampners
Post by: bluef100fe on April 17, 2013, 12:43:19 PM
Thanks guys
Title: Re: aftermarket harmonic dampners
Post by: frankenfords on April 18, 2013, 12:31:42 AM
I'm using a Powerbond SFI balancer, and there was no modification needed on any parts. Crank pulley bolted right on with no fuss, and belt is perfectly aligned. From what I can tell, the Pioneer SFI balancers are just repackaged Powerbond pieces. Hope this helps.