What? No Harmonic Damper?

[Kelpie]

Did you guy catch a copy of the latest Hotstuffs Mag, there was a mention on the Harmonic Damper by Alutec exclusive agent:

 

"There has been much internet hearsay and rumors on this common myth - that harmonic dampers are needed on aftermarket crank pulleys. people are getting their crank pulleys confused with the harmonic dampers found on some American domestic V6 / V8 engines, found commonly on their "muscle cars". These older American engines need an external balancer, AKA torsional damper / balancer to balance the crankshaft rotating assembly. However, this is non-existent in moden engines today as our engines are internally balanced. Technically, the harmonic damper does not exist in modern engines especiially so in Japanese and Korean makes.

What you may see on O.E pulleys found on some cars is a rubber ring called an elastomer. This elastomer is NOT a harmonic damper and DOES NOT aid in the balancing of the crank pulley in any way. The elastomer in the O.E pulley serves as an isolator, which is there to supress natural vibration and noise from the engine itself.

The elastomer is only found on selective car makes and not every car has one. Adding an elastomer, including the sealing agent to glue it to the pulley, adds weight to the pulley and defeats the sole purpose of installing a lightweight crank pulley - which is to reduce weight to gain lost horsepower and torque."

 

True?

 

Regards,

[Mage]

is this true? ..

[Kelpie]

is this true? ..

 

I don't know either hence I ask lor . Perhaps, the experts here can tell us more.

 

Regards,

[Falc]

It's true that some OEM pulley clearly doesnt have any rubber in between, those who have, it's also not sure if they act as damper or silencer.

 

But on evidence wise, havnt come across anyone with a broken engine because of lightened pulley. Lightened pulley plus lightened flywheel yes IIRC.

[Normal_aspirated]

not recommended fer conti engines..........

for japs, as their engines parts are very well-balanced (result less noise), so forged lightened crank pulley should post no prob. so far no problem on my prev Mazzie protege for 3 yrs.

Help low-end pickup only. High end no benefit. My S$0.02.

Edited October 29, 2006 by Normal_aspirated

[Brock]

Kelpie,

 

Before that HotStuff article, I saw it over here already. Here's another interesting read about the lightweight crank pulleys. Even Evo's are using them (Ralliart Lightweight Crank Pulley), as seen from this article. It's best to have a lightweight crank pulley WITH the harmonic damper.

Edited October 29, 2006 by Brock

[Brock]

According to this article, one of the company's employee, who used a lightweight crank pulley w/o the harmonic damper, had his pulley cracked into two.

[Kelpie]

Seems like crank pulley is ok to go ahead. I will get one soon. Thanks all. But now which brand to get? Alutech or RPM? Anyone have recommendation? usually costs how much har? Thanks again.

 

Regards,

Edited October 29, 2006 by Kelpie

[Falc]

Got meh?

Anyway, the damper is to damp the vibration on engine's crank as oppose to damping the pulley itself. So if pulley split, probably means that guy use lousy aftermarket pulley lah.

[Fcw75]

RPM one got harmonic damper it seems. I saw it at Riverview Auto.

[Zrun]

Many new cars do not have the damper in the crank pulleys.

It is combination of two factors: to cut costs and the overall improvement of engine quality/internal balance.

 

However these crank pulleys are still much heavier than lightweight crank pulleys. The heaviness provides good amount of damping effect.

[Cooldown]

The most important is will the belt slip.. My frd install another brand of crank pulley and after not long, the belt keeps slipping off for nothing.. don know is it the mechanic or the product.. so abit put off to install this product

[Zrun]

Slipping belt can be caused by belts in bad condition, bad belt tensioner, or belts length doesn't match very well. Very seldom have to do with the crank pulley.

 

If you plan to change crank pulley, might as well change the whole sets of accessory pulleys for maximum power..

[Cooldown]

Change whole set .. then think the car will be having super light throttle.. haha. Not to say the cost of all the pulleys..

[Kelpie]

I just installed an underdrive pulley. It does make the car feel lighter at pickup. Perhaps, due to the lighter weight, you will somehow hear the "unqiue" pulley sound when your start the engine. This translates to additonal noise to some. Once inside the car, I don't hear anything at all. I wonder if noise is an issue to those who have installed aftermarket pulley?

 

Regards,