Lite weight crank pully... is it worth it?

MMamdouh · Post by **MMamdouh** » Tue Feb 14, 2006 10:25 am

hi guys... is it going to add any power to the engine when i use a liter weight crank pully? it is not an UD pully 'cause it is the very same size as the OEM one... it is just not as heave as the OEM.

i didn't make a weight comparison but it can be some 30% liter so is that going to gain me any extra HP if i used this lite pulley??

MMamdouh

Joso · Post by **Joso** » Tue Feb 14, 2006 12:44 pm

It's giving you more power for sure. For what car? how much does it cost? Info please!

I think the worse it can do is a little worse idleing.

chronoti · Post by **chronoti** » Tue Feb 14, 2006 1:03 pm

Joso wrote:It's giving you more power for sure. For what car? how much does it cost? Info please!

I think the worse it can do is a little worse idleing.

worst thing it can do is distroy your crankshaft seals. most lighter ones they remove the harmonic dampner in it so they vibrate more. that vibrations distroys your seals rather quick. i hear good things performance wise but most people later on say that it wasnt worth having all the extra work to fix the new leaks.

MMamdouh · Post by **MMamdouh** » Tue Feb 14, 2006 1:45 pm

its a pully from a 2.0 vectra... we are planning to use it on the 2.0 nubira, cost 300 LE ($53.50).

i think the damper is not their at all... it was in one solid peice but it was lite indeed, i guess it was aluminum or so.

how much power gains are we talking about here?

MMamdouh

karim · Post by **karim** » Tue Feb 14, 2006 1:57 pm

The Crank pulley drives the A/Con, Alternator & P/Steering (where applicable).
What a Lightened & Balanced Crank Pulley does is to reduce load from the engine, allowing more power to the wheels. Immediate effect is better throttle response( Pick-up ).

"The way the pulley works ( and lets get this clear ) is it reduces power loss through the drive train and you gain more power at the wheels, the engines actuall output is the same. Now you ask does it work, HELL YES!!!!!!!!!!!!!!! This so far is the second most noticable power gain after a bored Throttle body, it works and well to, no noticable electrical power loss, idle is a bit smoother and revs easier, and from previous dynos results I've seen it prob gives 2-3hp more at the wheels from idle to top end, but past 4000 rpm the throttle body's pull seems to over shadow the pulley, but at low rpm the extra torque can be felt and the car is definitly quicker and more drivable".

About the vibration the original Cast iron pulley has a much higher rotating mass & being casted , are never properly balanced. That is why the rubber Harmonic Damper is so crucial.

daewooluvr · Post by **daewooluvr** » Tue Feb 14, 2006 2:27 pm

I was told the 2.0/2.2 engine were internally dampened. Not even sure what that means but basically the crank pulley has no dampener. Is this true?

I believe Tom from 360 can answer this.

Audacity Racing · Post by **Audacity Racing** » Tue Feb 14, 2006 2:29 pm

daewooluvr wrote:I was told the 2.0/2.2 engine were internally dampened. Not even sure what that means but basically the crank pulley has no dampener. Is this true?

I believe Tom from 360 can answer this.

+1

kinkyllama · Post by **kinkyllama** » Tue Feb 14, 2006 6:21 pm

Audacityracing wrote:
daewooluvr wrote:I was told the 2.0/2.2 engine were internally dampened. Not even sure what that means but basically the crank pulley has no dampener. Is this true?

I believe Tom from 360 can answer this.
+1

+2

Joso · Post by **Joso** » Tue Feb 14, 2006 6:34 pm

My bad, I though you were asking about the crankshaft.

MMamdouh · Post by **MMamdouh** » Tue Feb 14, 2006 11:54 pm

while doing the search for this lite pully we had an OEM 2.0 pulley and it had a damper ... it was so stiff that yuo can hardly recognize it.

MMamdouh

Post by **PrecisionBoost** » Wed Feb 15, 2006 12:35 am

All three of my 2.0L engines have a harmonic dampner integrated into the crank pulley. ( 2.2L as well )

It consists of a 1/16" thick hard rubber which mates the inner part of the pulley to the outer part of the pulley.

If I can dig mine up I will take a picture.

Reducing the weight of the flywheel and crank pulley can cause all kinds of problems..... but you really have to ask yourself if your after performance or longevity.

If you are adding performance parts your engine won't last as long anyways.... so I would say that the lightened crank pulley is a bonus.

The weight of the flywheel and crank pulley (combined with the forces created by the power steering, alternator, A/C, water pump ) help to smooth out the pulses from the cylinders.... they can be modeled exactly as you would a capacitor.

They store energy from the forcefull pulse of each cylinder firing and return that to the system during "low spots".

The bigger the weight the more energy is absorbed and returned.... which decreases stress.

So.... bigger capacitor smooths out pulsed voltage just like a bigger load/weight smooths out pulsed power loads

Sorry to get technical...... but most people immediatly think that a lighter pulley and flywheel are better than stock.

Trust me.... if GM could get away with 1 pound less metal and keep the reliability/longevity of the engine... they would.... since it would save them money.

Everything is there for a reason.... if you modify it you risk decreasing the life of engine components (such as crankshaft seals).... but for someone like me who is interested in performance..... the gains in throttle response and RPM drop off after shifts is more important than the life of the engine.

So....... what are you looking for.... performance or longevity ??

Post by **PrecisionBoost** » Wed Feb 15, 2006 12:37 am

Oh..... ya.... the engine doesn't have balance shafts.... so the crankshaft is ballanced internally........ the crankshaft dampners purpose is more related to smoothing out cylinder pulses to decrease stress on the crankshaft, bearings and seals than it is to help balance the internal engine parts.

MMamdouh · Post by **MMamdouh** » Wed Feb 15, 2006 8:28 am

chris@PrecisionBoost wrote:Trust me.... if GM could get away with 1 pound less metal and keep the reliability/longevity of the engine... they would.... since it would save them money.

thanks for the great info. you provided chris... i think Zikas is seeking performace so it is a tempting mod. to do.

concerning your quote here: the pully we are considering is an OEM crank pully off a '97 2.0 OPEL Vectra so GM did make a lighter pully for the 2.0 engine... i guess this rules out the threats of vibration and fouling crank seals 'cause this pully was designed for the street car so i guess it is not dangerously lite and will be capable of keeping the reliability/longevity at acceptable levels... or at least thats what i think.

actually that is the great thing about the pully as now you are sure it fits, it works and you can easly get it form any OPEL spare parts shop and those are all over the country here and since it is made by GM then it is manufactured to be procicly functional and reliable... comparing all that to an after market light pully i will get the OEM lite pully every time.

on the other hand i am not that experianced with performance mods so this is why i am asking... so far it seems logical to do it but i got to get more feedback from you guys... i know the lite one will cause more strane and all but having an "OEM" lite pully off a GM engine will keep this strane at an acceptable level... right?

MMamdouh

Zikas · Post by **Zikas** » Wed Feb 15, 2006 9:14 am

thank you all fro the very nice technical info u gave me and i think i would go for it since that i sawped my 1.6 L engine to 2.0 L and the engine i got is not that perfect as of the internals and stuff like this but it was done coz i was looking for some performance increase so i will buy the pulley and give u some feed back later (and by the way when changing the pulley i already have to change the seals coz they leeking oil so new seals + a new light waight pulley will go longer than all ather parts in the engine )

and i am thinking of NOS so the hell with the engine life span

karim · Post by **karim** » Wed Feb 15, 2006 10:50 am

What is the weight diffrence between the Vectra and the Nubira, is it few grams or kilos. Because the Honda stock pulley is like 2kilos and the aftermarket one is 675grams, so there is much diffrence but if it's just few 100grams, don't think you will notice the diffrence, any it's just $53 and anything will do to have free hp.

MMamdouh wrote:
chris@PrecisionBoost wrote:Trust me.... if GM could get away with 1 pound less metal and keep the reliability/longevity of the engine... they would.... since it would save them money.
thanks for the great info. you provided chris... i think Zikas is seeking performace so it is a tempting mod. to do.

concerning your quote here: the pully we are considering is an OEM crank pully off a '97 2.0 OPEL Vectra so GM did make a lighter pully for the 2.0 engine... i guess this rules out the threats of vibration and fouling crank seals 'cause this pully was designed for the street car so i guess it is not dangerously lite and will be capable of keeping the reliability/longevity at acceptable levels... or at least thats what i think.

actually that is the great thing about the pully as now you are sure it fits, it works and you can easly get it form any OPEL spare parts shop and those are all over the country here and since it is made by GM then it is manufactured to be procicly functional and reliable... comparing all that to an after market light pully i will get the OEM lite pully every time.

on the other hand i am not that experianced with performance mods so this is why i am asking... so far it seems logical to do it but i got to get more feedback from you guys... i know the lite one will cause more strane and all but having an "OEM" lite pully off a GM engine will keep this strane at an acceptable level... right?

MMamdouh

The original daewootech forum

Lite weight crank pully... is it worth it?

Lite weight crank pully... is it worth it?

performance Vs. engine life span