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Harmonic damper size considerations, timing tab, and oil cooler lines

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Old 06-28-2010, 10:33 AM
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Harmonic damper size considerations, timing tab, and oil cooler lines

Guys,

I am about to buy an ATI damper. I'm trying to figure out what will fit. The stock one I pulled was 6.75" diameter and 1.2" thick.

ATI offers 6.3" and 7" diameters. I recall the stock damper fit pretty tight with the stock timing pointer. But I suspect another 1/8" will clear fine. Has anybody run a 7" damper with the stock pointer?

ATI also offers 1.2" and 1.5" thick dampers. I recall the stock damper fitting pretty tight against the stock oil cooler lines that run behind the damper. I'm not sure if they'd rub if I went with the 1.5" thick damper. Has anyone run a 1.5" damper with stock oil cooler lines?

I called ATI tech and they recommend a 7"/1.2" combo or the 6.3"/1.5" combo for my motor. I suspect the 7"/1.2" is the safer bet fitment wise but just want to make sure.

Thanks.
Old 06-28-2010, 11:25 AM
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Re: Harmonic damper size considerations, timing tab, and oil cooler lines

Well, the diameter of the dampener didn't cause any interference issue with the stock cooler lines on my brother's 87 GTA. We used an 8" dampener and it fit without modification. The THICKNESS might be a different story. Ours was of the thinner variety where the rear edge was quite a distance forward of, say, the timing cover. One of the thicker dampeners where the rear edge is close to the timing cover..... not sure if that would cause issues with the cooler lines, only becuase we never tried it.
Old 06-28-2010, 11:41 AM
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Re: Harmonic damper size considerations, timing tab, and oil cooler lines

Yeah I know the diameter won't matter for the oil cooler lines but the thickness will, like I said. However the diameter will effect fit with the stock timing pointer.
Old 06-28-2010, 11:47 AM
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Re: Harmonic damper size considerations, timing tab, and oil cooler lines

I just measured a stock 6-3/4" balancer (sometimes referred to as a 7" balancer). It measures EXACTLY 6-3/4" in diameter. Thickness is a really thick 1.7". I can't remember what this came off of (probably not a TPI motor) but it's something late model with the timing tab in the 12:00 position (late model TBI engine??).

If I recall correctly, a stock TPI motor dampener is the thinner design (less than an inch and a half, just like you measured), and certainly thinner than whatever the one I've got came off of.
Old 06-28-2010, 02:55 PM
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Re: Harmonic damper size considerations, timing tab, and oil cooler lines

Well I ordered the 7"/1.2" model. Hopefully it will work out.
Old 10-15-2010, 04:10 PM
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Re: Harmonic damper size considerations, timing tab, and oil cooler lines

The 7"/1.2" worked fine.
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