the crank shaft its harmonic balance?

Originally Posted by 7419sundat

Compare it to an air filter. Yeah you can run your engine without one and get a little more power and better response but your engine won't last as long...

Originally Posted by lemon-fresh

It is such a polarizing issue, I have a set of NST pulleys and I'm still trying to decide I want to install them. I did see pics of one forum member who had his NST pulley shatter (wish I could remember who), it's what made me not rush into installing mine.

Probably just gonna talk to the mechanic about it.

Originally Posted by SS_Firehawk

That damper piece people think dampens vibration is a rubber gasket...that's it. It's made out of iron and heavy, not to magically remove non-existent super dangerous vibrations that emanate from our engine. It's the same reason they made the fluwheel a dual mass, to smooth things out, but it also saps engine response (and power). There aren't a lot of newer vehicles or engine designs that require an external damping mechanism. It's just a pulley. Even the stock piece is called a crank pulley. But alas, I'm wasting my breath to half the forum

Originally Posted by lemon-fresh

It is such a polarizing issue, I have a set of NST pulleys and I'm still trying to decide whether I should install them. I did see pics of one forum member who had his NST pulley shatter (wish I could remember who), it's what made me not rush into installing mine.

Probably just gonna talk to the mechanic about it.

Originally Posted by vitinvictor1

Anyone here with the stillen pulley installed?

Originally Posted by 7419sundat

So are you leaving yours on after you shell out all that money for your twin SC kit? What do the guys at Gtm recommend?

Originally Posted by DEpointfive0

I know the member personally who had the shattered crank, hell, I uploaded the pics, LOL
It was shitty install/crankshaft was bad

After the OEM pulley was put back on, it wobbled and even the cast iron one shattered

Oh, if you don't install them, I'll lowball you for your kit, lol



I do, it's great

Originally Posted by DEpointfive0

I think your point doesn't hold it's weight, but...
Whatever you say brother, no one is forcing you to install one.

I have yet to see anyone scientifically and empirically show that with an aftermarket pulley your engine won't last as long.

Originally Posted by SS_Firehawk

That damper piece people think dampens vibration is a rubber gasket...that's it. It's made out of iron and heavy, not to magically remove non-existent super dangerous vibrations that emanate from our engine. It's the same reason they made the fluwheel a dual mass, to smooth things out, but it also saps engine response (and power). There aren't a lot of newer vehicles or engine designs that require an external damping mechanism. It's just a pulley. Even the stock piece is called a crank pulley. But alas, I'm wasting my breath to half the forum

Originally Posted by wstar

Well, there's a lot of confusion on this issue about vibrations, dampening, and external vs internal balancing. I can't settle the matter for our engine, but I can clear a few things up to put the debate more on-point: Yes, our engine is "internally balanced", and that has virtually nothing to do with the debate about the pulleys.

An externally balanced engine means there's actually an asymmetrical counterweight system on the pulley, which balances against the otherwise-imbalanced crankshaft. You will definitely destroy an engine if you were to slap a random symmetrical pulley onto such an engine. Because our engine is internally balanced, there's no specific need for a balancing component on the pulley. The pulley itself is expected to have neutral balance (even weight distribution).

Even with an internally-balanced design like ours, the stock pulley includes a (neutrally-balanced) dampening ring to reduce vibrations. The debate is about whether replacing the stock pulley (poorly machined, crappy metal, with a dampener) with an aftermarket one (much lighter, machined to better tolerances, no dampener) is going to cause long term damage due to increased vibration.

On the "stock" side of the debate is the idea that the stock dampener serves to quiet important harmonic vibrations at specific RPMs, and that without it the engine will slowly tear itself apart (slowly wear out crankshaft bearings at the very least). On the "aftermarket" side of the debate is the idea that the (a) whatever vibrations the stock pulley dampens are relatively trivial and mostly about reducing engine noise heard by the user, and won't cause engine damage, and (b) the more-precisely machined aftermarket pulley is better-balanced to begin with.

There's little doubt that as you push an engine further beyond its design boundaries, you need to be more precise about balance and vibrational issues in general. The tricky question is whether our engine in basically-stock form needs that NVH ring for long-term health or not.