i have been debating this with fellow local enthusiasts for a long time. they argue it is no problem having a honda crank cut and they like comparing honda engines to small block chevys and 4g63's.

in my opinion, i would never ever have a honda crank cut. i would find a good one. just wondering what everyone else thinks on this.

 

Not a big fan of cutting honda cranks either but we have used an ls crank that was cut 10/10 and used clevite bearings during install.the car was daily driven and has seen boost to 22 psi with no problems yet.it was recently taken apart and the bearings/crank still look good.

 

I've run 1 cut crank for quite a while with no issues.

 

I ran one with over 40 passes on it it was polished 20 under
the final demise of it was arp rod bolt breaking

 

I wouldnt really want to run a cut crank ethier... I have heard Honda heat treats the journals and doesnt recommend grinding them.

 

I know there is a layer of metal on the crankshaft bearing surface, I think it's nickel. If you cut past that layer say bye bye...you'll eventually probably wear the rod bearing surfaces and/or spin a rod.

So don't cut a honda crankshaft ever! If you do it better be within spec and/or without cutting through that layer of metal that can handle the friction being produced.

 

I was runig a cut crank a .25 it ran with no problem I when with it 9.7 till I broke may oil pump but this time I will stick with one that isn't cut .

 

I'm sorry, may I know what's the reason for cutting the crank? Is it like grinding to lighten or knife-edging it?

 

No, he mean cutting the bearing jurnals (main/ rod).

I prefer to use std crank since they are thrown every where and damn cheap.

 

i wouldnt put a cut crank in my motor, ive seen a cut crank snap in a turbo setup

 

ive seen brand new cranks snap as well thats neithe rhere nor there

people have ran cut cranks with success, and some have beat the **** out them while doing it.

I know 10 under isnt an issue, and in my ride we needed to go to 20 under before we didnt have any oil pressure issues for some reason I ran it all season at 630/400 with no issues at all. In fact the ARP rod bolt snapped proving to be the weakest link

 

My old old motor had a cut crank .020, ran without a hitch for 6years daily off and on almost 25k miles boosted on an otherwise stock motor, then I built the motor and turned it up to around 600hp and 10krpm daily on E85 and still didnt have an issue.... I tore it down after about 3000miles and the bearings werent bad, but they didnt look good either. Im not saying its a good thing but if done right its not the end of the world and it will survive most low power setups IMO. However OEM cranks are around and can be bought rather cheap, I didnt have my crank cut origionaly the car came that way, if it was my choice I would search for a good OEM crank over cutting one for peace of mind.

 

I'm sure every one knows this, but theoretically you have a layer of oil at all times between the crank and the bearings, so there should be no reason you can't cut a crank.

Alot of oem K series cranks are used offset grind and gain stroke, and there is no issues there either.

 

theres still friction

 

I think it depends on the forging...we cut an H23 crank and it was really porous and looked like crap. As long as you have a good machinist and you are competent enough to check their work it shouldn't be an issue. Honda cranks are strong...look at what these Outlaw guys put their OEM cranks through. You just have to carefully check the **** because I see lame *** machine work 10 to 1 over good stuff LOL. There is just no pride in work these days.

I don't know about other guys but I have been running a crank that we welded and offset ground and I turn the **** out of the motor...cross traps north of 11K and since I'm the best driver on the planet I miss gears, do endos, beat it off the limiter, and when we are on the dyno and the shift light says stop..I just turn it a few hundred more to see what happens You just have to check the work IMO and make sure you have the hardness that you desire.

 

When a crank is offset grinded is it usually nitrided or some other surface treatment done?

 

Honda cranks are Nitrided from the factory just like aircraft crankshafts. There is an extremely hard surface layer that results from this treatment. When you machine the crank you lose that surface. As long as you have a good oil supply you shouldnt have an issue as long as it is magnafluxed to make sure there are no cracks, etc. I ran one in my spare engine and we routinely put over 30 lbs of boost on it.

 

If the shop is competent they will at the very minimum offer you a surface hardening (nitride) and/or heat treatment. As long as this is done, the crank should be as strong or stronger then a factory crank. As mentioned there are A LOT of shops out there that produce sh*tty work, so chose wisely.

For reference, all of our cranks only go to Castillo's Crankshaft out here in Los Angeles.