Is it advisable to "upgrade" to a lightened crank pulley? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

J ROK · 05-31-2008, 01:17 PM

So does anyone have anything BAD to say about smaller, lighter crank pulleys? cuz my friend just put one on his motor (not in car).

Is there anything we should be worrying about?

Pandapants · 05-31-2008, 01:41 PM

^messing up the crank bearings?

Def · 05-31-2008, 03:30 PM

It deletes the stock harmonic damper(bonded rubber ring), so you'll be increasing torsional vibrations in narrow RPM bands(the crank's natural frequency and its harmonic multiples). This isn't good for bearing life.

zavala · 05-31-2008, 10:02 PM

the gears for your oil pump in the front cover will most likely break from the horrible harmonics before any real damage is done to bearings. but then after that, no oil=toast motor

05-31-2008, 01:17 PM	#1
J ROK Zilvia Member Join Date: Jun 2007 Location: Lighthouse Point, FL Age: 40 Posts: 282 Trader Rating: (1) Feedback Score: 1 reviews	So does anyone have anything BAD to say about smaller, lighter crank pulleys? cuz my friend just put one on his motor (not in car). Is there anything we should be worrying about? __________________ AERO-K GARAGE

05-31-2008, 01:41 PM	#2
Pandapants Zilvia Junkie Join Date: Mar 2008 Location: SoFla Age: 35 Posts: 302 Trader Rating: (4) Feedback Score: 4 reviews	^messing up the crank bearings?

05-31-2008, 03:30 PM	#3
Def Post Whore! Join Date: Apr 2004 Location: Houston, TX Posts: 2,701 Trader Rating: (16) Feedback Score: 16 reviews	It deletes the stock harmonic damper(bonded rubber ring), so you'll be increasing torsional vibrations in narrow RPM bands(the crank's natural frequency and its harmonic multiples). This isn't good for bearing life.

05-31-2008, 10:02 PM	#4
zavala Leaky Injector Join Date: Jan 2007 Location: Kingston Springs TN. Age: 41 Posts: 124 Trader Rating: (0) Feedback Score: 0 reviews	the gears for your oil pump in the front cover will most likely break from the horrible harmonics before any real damage is done to bearings. but then after that, no oil=toast motor