crank question....

[Mojoe]

I want to swap the crank in the engine I bought cuz the gsxr has straight cut gears and the kat has diagonal cut gears. I was told there is about a 10hp gain by using the gsxr crank and there is also less outward thrust on everything and less chance of blowing the clutch basket and causing damage. So my question is, is the 1990 gsxr750 crank the same size as a 1990 gsxr1100? I can use an 1100gsxr crank. If so, I can get both on ebay...hopefully pretty cheap. I am not sure if I will read any replies before the auction ends, so I bid anyway. I think it is the same....just not 100% sure. It would put my mind to ease if I knew I was bidding on something I can use.

[The CyberPoet]

Re: crank question....

I don't have the answer for you, but one thing you said caused me to perk up:

I was told there is about a 10hp gain by using the gsxr crank and there is also less outward thrust on everything and less chance of blowing the clutch basket and causing damage.

To make sure no other readers get confused: this is because of the lower rotational mass of the GSXR crank and has nothing to do with which way the gears are cut (straight or diagonal).

Cheers
=-= The CyberPoet

[Mojoe]

To make sure no other readers get confused: this is because of the lower rotational mass of the GSXR crank and has nothing to do with which way the gears are cut (straight or diagonal).

I don't know if I agree with it having nothing to do with the way the gears are cut. Diagonal gears naturally have more friction on them, as well as a certain amount of sideway thrust....which means friction. More friction = less power, no? I could be wrong though. I am just going by what I was told by 3 different people. I have no idea what rotational mass a gsxr crank has compared to the Kat crank. I am ready to suggest it might be a combination of both. Whatever the answer, the gsxr crank is better than the kat crank for hp gain.