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I have heard people talk about the dampener also. Here are pics of the crank pulley front and back. As indicated by the arrows the crank has a ring on both side about 5mm wide and about 3mm deep that is made of a semi hard rubber like material. This I assume is the so called dampener. I do not know if they (Honda) tested it and after months of study decided right there is the perfect place for a piece of rubber to be and/or if it is a special rubber to cancel out a certain vibration or they just picked a random place on the pulley to put it. All I do know is that AEBS told me to run the stock crank pulley claiming that light weight ones put more stress on the main bearings causing them to wear faster. How much faster??? Don't know. Is it true??? Don't know either.
I assume that the Honda engineers are the only ones who know for certain. I wish we had one or two on the board so they could answer tech questions.
I agree but in Proauto's defense the waterpump pulley was made from stamped 2024 Alum (bad choice IMO) and this crank pulley is made from billet 6061. It looks pretty good as far as strength goes and I doubt that this will fail but the main question is the dampener.
You usually want to get the pulley rotate balanced since they dont come that way from the factory. I had the one on my old GSR rotate balanced up to 10k rpm.
A friend of mine had a tiny knick out the outter belt edge of the pully, and it ended up causing so much vibration on his crank that it killed the bearings, which scared the crank! It was a civic type-r N1 pulley.
The harmonic balancers in the stock pulley is the rubber part of it. It absorbs most of the vibration that can occur.
usually the pulley is balanced to the crank- by changing the weight of the pulley you are un-balancing the rotating mass of your engine. IF you were to balance the light weight pulley with your crank then you'd be safer than if you just slapped the pulley on.
I looked at this indepth on the smaller Honda motors back when I was racing competitevly and this is what I had discovered.
It is also advisable to balance your fly/clutch as well- you want your crank to have as little issues as possible. (obviously).
HTH
I have heard people talk about the dampener also. Here are pics of the crank pulley front and back. As indicated by the arrows the crank has a ring on both side about 5mm wide and about 3mm deep that is made of a semi hard rubber like material. This I assume is the so called dampener. I do not know if they (Honda) tested it and after months of study decided right there is the perfect place for a piece of rubber to be and/or if it is a special rubber to cancel out a certain vibration or they just picked a random place on the pulley to put it. All I do know is that AEBS told me to run the stock crank pulley claiming that light weight ones put more stress on the main bearings causing them to wear faster. How much faster??? Don't know. Is it true??? Don't know either.
I assume that the Honda engineers are the only ones who know for certain. I wish we had one or two on the board so they could answer tech questions.
The dampner is tuned to absorb a certain range of harmonic frequencies in the crankshaft. Without a dampner, the crank can twist and unload at those frequencies causing fatigue if not outright failure of the crank and crank supporting parts. Hence the name harmonic balancer although I'm not sure on this motor if it actually balances. In the V8 world that I'm more familiar with, RPM's in the range on this motor should call for a zero balance rotating assembly meaning that the flywheel and balancer don't actually balance the engine and are just another neutral balanced part in your drivetrain.
IMO, I think F20C engines are pretty well balanced out from the factory. If the harmonic balancer is to balance the crankshaft so how come it only have it on one side ? In this case if you change the flywheel then the balance of the crank will be off as well ?
