Lightened Flywheel VS Crank Pulley

[B16RacerN2NR]

Hope this is the correct forum...

There is something that I still can't figure out. I've tried searching every where but to no avail...

I understand why a light weight flywheel is good/better but what I haven't gotten the answer to is why changing over to a lighter crank pulley is bad. I figure they are doing the same thing. I'm sure changing the size if the pulley itself might cause some damage but i don't see how it can cause damage just if it's lighter... am I missing something here?

 

[phunky.buddha]

Harmonic balancer

 

[B16RacerN2NR]

I'll look in that section...

Cel, that still doesn'r explain how you can change the weight on one side of the crank but you can't/shouldn't on the other...

 

[K2e2vin]

Guess what's attached on the crank pulley side of the crankshaft? Yep, oil pump.

 

[MikeBergy]

I'll look in that section...

Cel, that still doesn'r explain how you can change the weight on one side of the crank but you can't/shouldn't on the other...

It has next to nothing to do with weight reduction. The reason most don't change the pulley is because most aftermarket crank pulleys don't utilize a harmonic damper, which is the main reason for retaining the stock pulley.

Also, consider the real reason for changing the flywheel out for a lightweight unit - lower moment-of-inertia. Look at the MOI for a disk.

List of moments of inertia - Wikipedia, the free encyclopedia

The formula is Iz = m(r^2)/2
Reducing the weight on a flywheel that is nearly 12 inches diameter will much more directly affect the MOI of the assembly than a reduction of weight from a pulley that is only approx. 6 inches in diameter. There is a factor of 4 decrease for the flywheel weight reduction in comparison to an identical weight reduction on the crank pulley, assuming those are the correct diameters. The MOI directly affects the engine's ability to rev quickly; it is not solely dependent on the weight of the rotating mass but also the distance the mass is from the rotational axis. There's the short answer for why it is more effective to go with a lightweight flywheel and leave the pulley stock.

 

[B16RacerN2NR]

ah ok... that's more understandable...thanks

 

[1goldteg]

How do you guys feel about the N1 crank pully from Honda? I would think it would be engineered correctly for the application...

Mike

 

[E_SolSi]

the N1 pully still does not have the pressed rubber core for absorbing vibration

 

[TurboMirage]

get your stock flywheel machined...

 

[E_SolSi]