n1 crank pulley


Ernie said:
I ran one for 10k on my b18cR with no probs, tracked and down the 1/4 regular.
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^This is exactly where these things are meant to be used. NOT on a road car.

It is nothing to with balancing or vibration, maximum RPM or how hard you drive. It's about harmonics, you know, the things that make tuning forks sing. The crankshaft is subject to them at certain revs and if undamped they will quickly ruin bearings and oil pumps. If you use this on a race engine, you go up and down the revs and pass quickly through the critical speeds, so the effects are inconsequential, but on a road car you are risking sitting at them which is when **** gets knackered.

You should only use these on race B16s, they are NOT recommended for B18s and I imagine this will be due to the longer stroke making the critical speeds lower.

Your engine though, if it's not worth much to you then go for it, that extra 1bhp will feel sweeeet! :nice:

P.S: I've said all this before. ;)

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It was still a road car I drove most days and to and from events...

I was just sticking some 1st hand expirience in... for all I know it may have gone bang if I'd left it in the car, or it may have lasted another 100k, we'll never know.
 
I just don't get why you would want to fit one? As said above all for a 1hp gain but with a large risk thrown in. I bet you would see a bigger gain using shell optimax over supermarket fuels. If you want to make the engine a little rev happy try a lighter flywheel, this will have a bigger effect than under driving the alternator.

This is a pretty good article from Laskey Racing on why you shoul use a harmonic balancer

Harmonic waves can travel thru the drive train and thru the crank. If there is nothing at the end of the crank to absorb the wave, it will travel back in the opposite direction to meet the next wave. This causes the unfavorable harmonic vibration. The first thing to take the abuse is the oil pump gear and you know what happens when that breaks. ALSO, pulling weight off of the crank that close to the center line will add ZERO horsepower or rpm capability. Don't fool yourself on this. Think of how big and thick the counter weights are on a crankshaft. The harmonic balancer is just another externally added counterweight that happens to absorb negative wave energy. Honda engineers were not stupid or naive. Don't try to out think them in this case, use a harmonic balancer.

Personal experience...We abuse the drive train launching at 8000 rpm and shifting over 10,000 rpm. The aluminum under the flywheel bolts started to eat away and the flywheel started to vibrate back and forth. When it came completely loose it sent a shock thru the crank so strong that it snapped the key holding the harmonic balancer in place. The balancer spun on the crank, put the crank fired ignition out of time and shut the motor off. When pulling everything apart, we found that the shock wave had actually also bent the crank to the point where it was unusable again. This proved to me the useful purpose of a harmonic balancer. We run steel flywheels now, BTW.
 
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rs250nut said:
I just don't get why you would want to fit one? As said above all for a 1hp gain but with a large risk thrown in. I bet you would see a bigger gain using shell optimax over supermarket fuels. If you want to make the engine a little rev happy try a lighter flywheel, this will have a bigger effect than under driving the alternator.

This is a pretty good article from Laskey Racing on why you shoul use a harmonic balancer

Harmonic waves can travel thru the drive train and thru the crank. If there is nothing at the end of the crank to absorb the wave, it will travel back in the opposite direction to meet the next wave. This causes the unfavorable harmonic vibration. The first thing to take the abuse is the oil pump gear and you know what happens when that breaks. ALSO, pulling weight off of the crank that close to the center line will add ZERO horsepower or rpm capability. Don't fool yourself on this. Think of how big and thick the counter weights are on a crankshaft. The harmonic balancer is just another externally added counterweight that happens to absorb negative wave energy. Honda engineers were not stupid or naive. Don't try to out think them in this case, use a harmonic balancer.

Personal experience...We abuse the drive train launching at 8000 rpm and shifting over 10,000 rpm. The aluminum under the flywheel bolts started to eat away and the flywheel started to vibrate back and forth. When it came completely loose it sent a shock thru the crank so strong that it snapped the key holding the harmonic balancer in place. The balancer spun on the crank, put the crank fired ignition out of time and shut the motor off. When pulling everything apart, we found that the shock wave had actually also bent the crank to the point where it was unusable again. This proved to me the useful purpose of a harmonic balancer. We run steel flywheels now, BTW.
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thanks for the good advice, this is all i was looking for rather than the shite other people posted just saying im stupid with no back up for the reason. probably going to go against it now and look at the ati ones .

cheers
 
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