What does 'knife edging' the crank give performance wise? Is it just to shave weight off of the crank? My motor is apart so I'm wondering if knife edging would be something beneficial? Would it cause problems down the line? Any help appreciated.

 

Shouldn't cause any problems if done correctly. And yes the main reason is to save on rotating mass, just like your lighter flywheel. Another benefit is to balancing it to exact spects. Also with less weight you will be able to spin your engine that much faster.

 

Also I've heard that knife-edging isn't very effective on Motors like ours. Old school muscle cars have their cranks partially submerged in the oil in the pan. So knife-edging will effectivly "knife" or "cut" through the oil as it spins. But because Our cranks are not submerged, it is unnessacery. A good crank balancing is probably the most you should have to do. At least thats what i've heard.


[Modified by egghead, 9:33 AM 11/8/2001]

 

 

Yeah...pass on the knife edging. Your bearings will thank you.

 

>>Yeah...pass on the knife edging. Your bearings will thank you.<<

How does knife-edging the crank affect bearing wear?

 

It will change the weight and more importantly the balancing. Anything other than perfect balancing will have an adverse effect on the bearings. I had my motor apart last winter to redo the bottom end and the machine shop that did the balancing checked and re-checked everything, balanced the assemblies, and recommended I NOT do any knife-edging because doing that would have made things very difficult to rebalance correctly. I went along with his recommendation.

 

Lots of wierd flexing and torsional changes happen to a crank under high performance conditions. Those counter weights smooth things out. Without a good balance, everything transfers to the bearings. Also, you need to keep your stock harmonic balancer to control crank flex.