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Crank Pulley/Harmonic Balancer
clutch_kick - 23/6/15 at 08:04 AM

The americans seem to be pretty much of the idea that this is a sacred piece in the engine. The uprated ones are scaringly expensive too ( ATI or BHJ Dynamics). They claim that removing it is the fastest way to disintegrate your oil-pump and crank.

If the bottom end is properly balanced ( I mean OCD-balanced ) do you really need it? can a solid pulley be used instead?

daviep - 23/6/15 at 09:06 AM

I believe the crank shaft damper is intended to reduce vibration caused by the crank twisting and relaxing as each power stroke is delivered as opposed to improving the balance of the bottom end.

So if understand correctly then balancing the bottom end will not reduce the need for a damper.

Cheers
Davie

mark chandler - 23/6/15 at 09:27 AM

On a kit car which will only cover a limited mileage no need to worry, if you expect 100,000 miles then keep one

30 years ago they hardly existed, dual mass flywheels came in 20 years ago and plenty of these get junked as well.

MikeRJ - 23/6/15 at 01:04 PM

quote:
Originally posted by daviep
So if understand correctly then balancing the bottom end will not reduce the need for a damper.


Correct, it's for absorbing torsional vibration energy, which balancing will not significantly affect. Depending on the engine, running without the "harmonic balancer" (it's a damper in reality) may have relatively little impact or it could cause premature fatigue failure of the crankshaft (very premature on some older engines).

[Edited on 23/6/15 by MikeRJ]