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Registered:
May 2002
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3S undersized crank pulley??
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Sat, 15 May 2004 14:31
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This is going to be a stretch but I was wondering if anyone with a 3S-GE or 3S-FE has ever installed an Unorthodox Racing 3S lighten undersized crank pulley or something similar? Would you recommend it? Is there anything local, off the shelf in Australia?
I have a need to chase an oil leak which involves taking off the cam covers which means a 4 hour job. This would be a good opportunity do the timing belts etc. So I thought maybe it would also be a good time to install a undersized pulley.
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Location:
Perth
Registered:
June 2002
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Registered:
May 2002
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Re: 3S undersized crank pulley??
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Sat, 15 May 2004 16:00
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Ahh the memories are coming back
Not too sure who is right but this is what is written on the FAQ at UR
http://www.unorthodoxracing.com/faq_pulleys.html
4) "Is my crank pulley a harmonic/torsional/vibration damper or a harmonic balancer?"
People are getting their crank pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term that is used loosely in the automotive industry. Technically, this type of device does not exist. The "balancer" part comes from engines that are externally balanced and have a counterweight cast into the damper, hence the merging of the two terms. None of the applications that we offer utilize a counterweight as part of the pulley as these engines are internally balanced.
The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that looks similar to a harmonic damper. The elastomer in the OEM pulley serves as an isolator, which is there to suppress natural vibration and noise from the engine itself, the A/C compressor, P/S pump, and alternator. This is what the manufacturers call NVH (Noise Vibration & Harshness) when referring to noticeable noise and vibration in the passenger compartment. It is important to note that in these applications, this elastomer is somewhat inadequate in size, as well as life span, to act as an effective torsional damper. If you look at the pulleys on some of the imports there is no rubber to be found at all. We have samples of these, mostly from Acura/Honda, the Nissan Altima, 1.8L Eclipse, 2.3L Fords, Chrysler 2.2L's, and 1.8L VW's, to mention a few. This is not to say that with our pulleys you will hear a ton of noise or feel more vibration from your engine compartment. Most who have installed and driven a vehicle with our pulleys will notice the engine actually feels smoother. This is a natural result of replacing the heavy steel crank pulley with a CNC-machined aluminum pulley. NVH is variable and unique to every car. NVH will increase with the installation of an aftermarket intake and/or exhaust, for example. Think of OEM intake systems in newer cars, they use baffles and resonators in the intake to quiet all the intake noise. Aftermarket intakes eliminate these resonators and create dramatic increases in engine noise from the throttle opening and closing. So to most tuners, certain types of NVH can make the driving experience more enjoyable.
The purpose of a traditional harmonic damper is to protect against crank failure from torsional movement. This is not necessary in most modern engines because of the many advances in engine design and materials. Factors such as stroke, displacement, inline, V configurations, power output, etc., do determine when and how these harmonics and torsional movements occur.
Again, there is a lot of internet hearsay about the pulleys. When engine problems occur, too often people are quick to blame the pulley first, rather than taking the time to look logically into why there was a problem. We hope that after reading this you will understand the crank pulleys better.
6) "Will these pulleys cause premature engine bearing wear?"
This is a fear many prospective owners have and is a valid concern since we are dealing directly with the rotating assembly. Fortunately it is another urban myth with no basis in fact. The fact is that our pulleys have the opposite effect on engine bearings. The combination of tight tolerances, quality control, perfect balance, and dramatic weight loss versus the stock pulleys reduces stress loads on your engine, extending the total service life you can expect from your engine. Engine bearing problems are purely associated to poor engine maintenance, use of heavier than factory recommended oils, improper engine building practices (which includes poor balancing), excessively revving engines when they are cold, and owners expecting their factory oil pumps to handle engine power outputs beyond 3, 4, even 5+ times the stock power levels.
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Location:
On your mum!
Registered:
May 2002
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Re: 3S undersized crank pulley??
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Sat, 15 May 2004 23:16
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If you have seen what happens to the crank end when it is the victim of insufficient harmonic dampening then you might just reconsider that. I have just recently seen the result on a Chrysler 6 (internally balanced race engine) and the pulley was actually welded to the crank from insufficient damping. The cure? They fitted a decent unit from Romac. They did however concentrate on reducing the rotational mass within the engine (ie knife edge the counterweights).
When it comes to externally balanced engines (as you mention V8s etc) It is generally only "big block" engines that require external balancing simply due to the amount of weight in the piston rod assembly, that they did not have sufficient room inside the engine to balance it.
The rest of what you said seems to make sense though - albeit that it smacks of a crank pulley manufacturer advertisement.
My 2c 
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Registered:
May 2002
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Re: 3S undersized crank pulley??
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Sun, 16 May 2004 03:39
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I've just communicated with someone in the USA who had one. Reckons the engine did rev quicker. His engine blew but apparently not pulley related.
I think I'll go with the stats and not bother importing this. If it was a good mod more people would be doing it. But if Nevo has one then that might spark my interest again. I've emailed John Harris but hasn't replied as yet.
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