Unorthodox Racing Pulleys,Cam Gears,Flywheels
Feb 22, 2004, 02:04 PM
#18
I have heard that new crank pullies tha tdont have harmonic balancers can damage the crank and or engine. Does this one have a harmonic balancer and if not do you anything about that? not trying to be rune or anything just get some good information.
Feb 23, 2004, 01:37 PM
#19
The “Harmonic Balancer” Debate
People are getting their crank pulleys confused with the harmonic dampers found on 90 degree 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 some of the pulleys on older 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 feel’s 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.
People are getting their crank pulleys confused with the harmonic dampers found on 90 degree 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 some of the pulleys on older 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 feel’s 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.
Feb 23, 2009, 09:36 AM
#20
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Just to clear up the power gains from weight issue... Torque is a force applied at a certain distance from the center of a rotating object. Newton found that force is an object's mass multiplied by its acceleration. Therefore if you reduce an objects mass you reduce the force (think horsepower in this case) required to move and in a rotational case you reduce the torque required to turn it. If the engine needs less torque to turn the flywheel it can use that available excess to turn your wheels instead. A good estimate of power gain from reducing rotational weight is 7 HP for each pound lost.
I'd like to add here that if you own an Evo IX MR you will need 4mm of shim for your starter if you use the Ultra-L flywheel from Unorthodox. I found this out the hard way and I have informed Unorthodox about the problem. Hopefully they will fix the flywheel or include the shims with the flywheel. So far the performance with the new flywheel has been excellent. It really improves the rev matching between shifts for nice smooth transitions.
I'd like to add here that if you own an Evo IX MR you will need 4mm of shim for your starter if you use the Ultra-L flywheel from Unorthodox. I found this out the hard way and I have informed Unorthodox about the problem. Hopefully they will fix the flywheel or include the shims with the flywheel. So far the performance with the new flywheel has been excellent. It really improves the rev matching between shifts for nice smooth transitions.
