As quite a few crankshaft pulleys consist of torsional damper (2 piece bonded with rubber between), what effect does this have on the engine if the OEM item is replaced with a lightweight alloy item with no torsional dampening?

If the crank/flywheel and clutch where a balanced assembly would this help in reducing the need for torsional dampening?

Thanks all.

 

It's all a question of how much smoothness you want, the better the balance the better the smoothness, but plenty of engines don't have pulley with damper bit, not needed on the cossie as the flywheels are so shockingly heavy, there is plenty of weight to smooth out vibration on a cossie apart from front pulley.
tabetha

 

I am asking as I have the chance of one for a RS2000 16v I4. The flywheel has been lightened along with a clutch/flywheel and crank balance.
I have read somewhere, removing the torsional damper can be bad for the crank, last thing I want is my newly rebuilt engine going tits up for the sake of a pulley.

 

Removing out of balance weight can never be a bad thing.
Weight is there anyway but is balanced, some better than others, the crank is not going to go bang if you stick on a lighter front pulley, though any out of balance may be made worse in respect of vibration, though not so much as you'd even notice.
The cranks are all balanced seperately to other components as they are the heaviest rotating mass, so need to be, so you are quite safe to put on a alloy front pulley.
They didn't use damper pulleys years ago, they are only used a additional smoothness aid.
I wouldn't hesitate to use one, if I wanted to, if only for weight saving.
tabetha

 

This is what frightens me lol http://www.atiperformanceproducts.co...mper_dinan.htm

 

You are missing lots of points here.
It is a totally different six cylinder engine he refers to, with a larger heavier crank, more rods, more pistons, more weight.
He is primarily talking about UNDERSIZE power pulleys, which as a consequence are even lighter, he cites severe damage but gives no results/evidence.
In an ideal world there would be the same weight at each end of the crank, but try as I might I can't think of a single one where there is.
It is true that inbalance causes problems, BUT he does not offer any criteria by which he considers damage.
If you have a std engine the parts are balanced seperately as they do not know which particular pulley etc will be picked off to go with which engine, so it is all a compromise, yes it would be better if it were balanced better of course, as would any engine.
He mentions race bmw engines which are a world away from the needs of a road going rs2000 engine.
Everything doies fatigue, ie has a life expectancy, but it's fatigue is not what is going to be the first determining factor to make a crank suffer a fatigue failure, most likely it will be the engine is worn out first light years before fatigue plays a part.
No mention is made of engines that do not use a harmonic balancer, which is more than do use one.
What I am saying is it is not something that is going to happen in weeks or even years where fatigue plays a part in your engines demise.
Ask yourself how many broken cranks have you seen compared with how many that have been ruined by normal wear and tear and lack of decent oil ?
tabetha