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#1 Harmonic Damper

Posted: Mon Jan 10, 2011 11:59 am
by chrisvine
Does anyone have experience or advice on the benefits of changing from the standard harmonic damper to an upgraded one, such as offered by Rob Beere?

Someone with a number of classic Jaguars suggested that it was worthwhile upgrade. However I'm not sure whether I'd be better spending the money elsewhere on the restoration. My engine is at VSE and is just about to be re-assembled so I will have to make my mind up fairly soon.

Thanks,
Chris

#2

Posted: Mon Jan 10, 2011 12:06 pm
by Heuer
Not had one fitted to my VSE02 and there is no sign of problems after 10 years and 35k miles using the standard one. The fluid damper may pay dividends if you regularly red line the engine but as most E-Type driving is done between 2,000 and 4,000 the ?500 seems a lot to pay unless you are going racing or doing track days.

#3

Posted: Mon Jan 10, 2011 12:18 pm
by christopher storey
The function of the damper in straight six cylinder engines is to damp the crankshaft harmonics ( IIRC second order harmonics) which will otherwise lead to crankshaft fracture at an engine speed which varies with amongst other things the length of the crank and the relationship between stroke and con rod length but which generally speaking if undamped in modern engines ( by which I mean post WW2 ) will occur between about 4500 and 6500 rpm , and most often in the region of 5800 rpm. It is certainly worth replacing your original damper during an engine rebuild, because the rubber separating but connecting the two halves of the damper will now be c.40 years old, but these cost about ?90 . Spending a lot more than that is, as David says, unlikely to be money well spent unless your engine is regularly going to enter the danger range of rpm for prolonged periods