I know that some may come in here and just be astounded at how dumb this question may make me look, but this is for real, an honest question.

Has anyone Knife Edged their crank with a die grinder before, carefully, not half assed? I ask because i have all the tools to do it, but not on a lathe.

Before the flames roll in extra crispy, YES, the crank would still be getting balanced properly by my engine builder after i massage it. I just figured $200 saved here, could be put to good use elsewhere in the build.

Anyone?

plenty of V8 guys do it, no reason why we cant to ours.

long as you keep it conservative and clean it'd be sweet!



I choose the technology built for land speed records... not the technology built to save on emissions and gas mileage.

You can do it, but you need to have it balanced afterwards. Might take off more of one weight than another.

I'd be worried about cracks.


- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs

I don't see why not, as long as you know what you're doing. If this were posted by nooby mcsixteenyearold, I'd be screaming "NO!", but you seem to know a thing or two, so I say give it a go.


2010 Honda Fit LX

As long as you take measurements and make sure to remove the same amount from all the weights it will probably work. Be easier for your machinist to balance as well.


"Oil Leak ? What oil Leak ? Oh, Thats Just The Sweat From All The HorsePower!!"

I should of taken pics but I did my crank, then shipped to get treated and balanced, takes time and patience.

"As I lay rubber down the street, I pray for traction I can keep, but if I spin and begin to slide, please dear God protect my ride." -Amen

lol, i like hearing from nooby mcsixteenyearold...they always have funny stuff to say

Oedwards wrote:I'd be worried about cracks.

huh? why would it crack?



I choose the technology built for land speed records... not the technology built to save on emissions and gas mileage.

I think people are getting a little ahead of themselves with my question lol. I really only meant using a die grinder to make the edges of each counter weight pointed, instead of the current rounded state. That was all really.

I would score a centre line first so i would know if i were removing too much material from 1 side, and not enough from the opposite side, of each counter weight.

I was hoping someone that has done this before could post some pictures just so i could get a sense of how far to take in the edges with the grinder.

I took my crank to a machine shop a few years ago and this is what they did to it. They called it bullnosing.

I didn't do this myself, but this is the crank that went into my engine.

I bet that thing revs like a bike


see ya!

Here is a decent link, there are plenty of DIY's that do it.. but its labor intensive... Lots of resources out there.

http://speedtalk.com/forum/viewtopic.php?f=1&t=20077

Note, if the crank is a pretty color plue and yellow in some areas like its been heated you will not be able to cut it with a carbide bit... those areas will have to be ground because they have been induction hardened... I don't know of any engines in J's that do have induction hardened cranks, but its something to watch out for.

I would be VERY careful if your building with hefty rods and pistons such as Eagle H beams... If you take too much off the counterweight the machinist will not be able to balance the assembly. (remember what the counterweights are there for...) And will have to add quite a bit of weight back to the counter weight if he has an area left to do so.

I would read up on fluid dynamics too so that you can perfect the shape, what most don't know, a rounded leading edge and a tapered to a point trailing edge are most efficient...not what you usually see.. which is the other way around or pointed on both leading and trailing edge.



Buildin' n' Boostin for 08' - Alex Richards

Alex Richards wrote:
I would be VERY careful if your building with hefty rods and pistons such as Eagle H beams... If you take too much off the counterweight the machinist will not be able to balance the assembly. (remember what the counterweights are there for...) And will have to add quite a bit of weight back to the counter weight if he has an area left to do so.

Luckily in the LD9 world the eagle rods and forged pistons weigh less than the stockers.

So if my rods/pistons are much lighter then I can be more aggressive in taking weight off the crank?


PSN ID: Phatchance249

Thanks guys this has been really helpful! I've found another site, mind you it's a site that sells 4g63 cranks, but with good pictures of whats been done to the leading and trailing edge of the cranks. FFWD "Butcher" Cranks

Wow will they do a ecotec crank? I would like a l61 crank with le5 stroke. For my new engine that way i could use all le5 rods and pistons.


see ya!

Ffwd did the crank I had in my talon. They do very exceptional work. Darren is a great guy to deal with as well.


"Oil Leak ? What oil Leak ? Oh, Thats Just The Sweat From All The HorsePower!!"