Lighten Crank, flywheel yamaha YZR 6

[uamir]

Does anyone have any ideas on how the lightened crank shaft and flywheel on Yamaha YZR6 engine would affect the engine performance and is it worth doing it?

[Wesley]

First, I would think about why you would lighten it in the first place. Answer these questions for yourself first.

What effect does it have on the mass and moment of inertia?

What effect does this have on power, power/weight?

How much does it cost, and what effect does it have on your reliability?

[ibanezplayer]

Wesley has posed some good questions.

Usually whenever weight is removed from a crank on a bike(knife edging), it is not aimed at overall performance, in fact most of it's "performance" gains become negligible based on what sort of oil system/setup you are running.

Having said that, you probably know all this if your asking...In my opinion, it's not the best thing to do(reliability?), but, we have run a knife-edged / lightened crank in the past. Just be prepared to justify it, like everything else in these competitions.

[michaelwaltrip]

we ran a lightened crank and rod setup this year with excellent results. it's been the best engine package we've had since we started running the r6 in '03.

falicon did an awesome job, at a very reasonable price, and quick turnaround. we have had the engine in the car since march, and it's proved to be very reliable.

in my opinion, any time you can take weight out of the 120lb pig that is the r6 engine, it's a good thing. lessened rotating mass could be a bad thing if you're down on low-end power, as you could experience problems keeping the car in the powerband.

it most likely won't have much of an effect on your peak power number, but it will reduce friction inside your engine, rev faster, and generally be much more fun to drive than a stocker.

[VFR750R]

[QUOTE]
falicon did an awesome job, at a very reasonable price, and quick turnaround. we have had the engine in the car since march, and it's proved to be very reliable.
QUOTE]

i thought i smelled a shameless sponsor plug and low and behold...its posted by michael waltrip.
http://fsae.com/groupee_common/emoticons/icon_wink.gif

[CSUNFormulaOne]

Right now we are trying to justify a knife edged crank for the very same motor. The price is very reasonable but we are more concerned with reliability.

Let me know if you decide to go with the knife edged crank. Maybe I could sell you ours if we don't use it.

[Wesley]

Originally posted by michaelwaltrip:
lessened rotating mass could be a bad thing if you're down on low-end power, as you could experience problems keeping the car in the powerband.


I'm curious to know why you think this is so?