This is a long shot but does anyone know what the RPM's range(s) is(are) for the crank vibrations for which the stock damper is designed? Early 60's light duty 3 speed manual and the 9.25" clutch BTW.

I ask because I have an engine vibration in the 2000-2400 rpm range. Vibration is still there when sitting still and revving the engine. The damper is 53 years old and so I wondered if the damper rubber getting hard could no longer be able to properly damp a crank vibration.

Edit to add: And maybe I am overthinking this.... if the damper is for an internal crank vibration how would I feel it on the outside?? May just be time to put in that new clutch and see if that fixes it....(Yeah, yeah, throwing parts at it.. but may just be faster!)

They can be calculated and are based on stroke and most have several orders, or rpm levels that they encounter shaking at throughout its RPM range. Shorter stroke engines are less susceptible to harmonic shaking than longer stroke engines. Also, the elastomers durometer hardness is specific to the engine also in aftermarket dampers, so a V8 damper, even though it may fit an inline engine crank snout will not only have a different harmonic frequency range it is tuned for, but it will also often times have a different durometer rubber ring to tune that frequency range of the V8 engine it was designed for. Meaning it more than likely will not dampen the harmonic frequencies effectively for the inline engine, even if it is the same stroke.

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There's no such thing as too much cam....only not enough engine!

Tnx; while I am an engineer, I have just started to learn how to compute and think about this subject, and am nowhere near to having the knowledge or the answers for any engine.... and may never get there. So, I thought someone here might know for the /6.

Good general info IMO, and a good point in the V8 vs inline dampers... which I suspect sez that while a 440 damper may fit, it very likely won't be right/adequate for a /6, unless it just worked out that way by chance.

Tnx again.

If it's a vibration you can hear/feel, it's nothing the crankshaft pulley/harmonic balancer/vibration damper can affect.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Tnx.

New clutch and pressure plate.... vibration gone.