... on a built boosted H-series motor. Looking for 400whp+. I've heard knife edging can weaken the crank a bit, is this true?

 

i would like to know myself

 

also - what is the main purpose of knife edging a honda crank - cut through oil, or reduce weight? If its just for the oil, It won't really be worth it to me because I have an aftermarket windage tray that takes care of that problem.

Any other comments?

 

ttt

 

Honda cranks don't pass through the oil.

The whole purpose of knife edging is for cutting through the oil and LOL aerodynamics.

Another thing....most professional drag racers don't have knife edged cranks....you decide.

 

I ran them in my race motors - dry sump and wet sump motors - and they made absolutely now difference on the dyno...removing the weight from the crank also made the crank flex more, but I think that is more from dynamics than from actually weakening the crank. Both of them that I had had done broke eventually - I have used the stock cranks ever since and have not had any more broken cranks. I personaly don't see that it is worth it.

If you want to get rid of the oil being whipped by the crank, go to a dry sump oil system - they remove the oil from the pan before it has a chance to get slung around by the crank.

Kirk

 

I'm installing one of these ---> http://www.crank-scrapers.com

maybe it will have a similar effect?

 

It will help get the oil off the crank, yes, but if you are doing any cornering the oil will go around the scraper and end up on the crank again. Is it helpful...yes...is it a bandaid as opposed to a real solution...yes. What is the cost?

Kirk

 

it was like $45

 

I agree w/Gtpilot.
The crank will become weakened if material is removed, as does anything else that has mass.

Knife edgeing your crank won't 'make power' either, it will just enhance your accereration just like a lightened flywheel. If you do get this done, make sure you balance the crank. Its a worthless upgrade, imo though.

 

yes, the hombre gato has a point. Its basically an old V8 trick if you may...you dont want to loose too much rotational mass, your motor will spin super fast but you will have no torque. Just spend your money on having your motor balanced/blueprinted.

 

I was talking with Kurt of KG Engineering in Huntington Beach about knife edging my crank a few weeks ago. He mentioned that when the idea first came out...many pro drag racer did it because of the possible advantages but after awhile...they found no real advatage so knife-edging is not done anymore. Kurt mentioned that a light weight flywheel will be good enough to reduce rotational mass and increase acceleration.
Hope this helps...Peace