Turning a honda crankshaft = bad???
 

I had my crank turned because I thought that it would be a good idea to ensure a good bearing surfaces in my built DOHC ZC. I mentioned something to this extent on dseries and a couple of guys basically said that there is some special OEM finish to honda crankshafts and that having them turned is a bad idea. Does anyone have any info about this?

It would seem to me that if there was some special finish to OEM honda cranks that it would eventually wear off.

Re: Turning a honda crankshaft = bad???
 

having the crank turned and ordering oversided bearings is standard machining practice if the journals on the crank are grooved or worn too badly for you to be able to just polish them. if you didnt run the engine without oil pressure, you could have just micro polished the journals and ordered stock size bearings. i think the "special finish" is just the polishing that is done to every crank. ---- d series.org

Re: Turning a honda crankshaft = bad???
 

yes there is a nitride (is that the right word?) coating on the oem honda crank

Re: Turning a honda crankshaft = bad???
 

Alright so my crank was turned .010" should I even worry about this?

Re: Turning a honda crankshaft = bad???
 

.01"? you are gonna need some THICK bearings

Re: Turning a honda crankshaft = bad???
 

.010" undersize turning is VERY common, on V8's.........rarely heard of it being done on Honda's since the cranks are very tough. I was told if you ---- up the crank in a Honda, better off finding a new one.

Either after turning they are not as good, or the OS bearings are junk.

Re: Turning a honda crankshaft = bad???
 

.01 just seems like too much. considering that the bearing tolerance is like .0015. i dont think even the thickest honda bearing will correct a .0115 tolerance. or are the OS bearings you are talking about not honda?

Re: Turning a honda crankshaft = bad???
 

usually clevite 77's for the OS bearings

Re: Turning a honda crankshaft = bad???
 

No, I have ACL's and all of my bearings are specing out fine. I'm just curious if I need to trash this crank and buy a used one.

Re: Turning a honda crankshaft = bad???
 

are they the oversized ACL's?

Re: Turning a honda crankshaft = bad???
 

Jesus christ.....yes they are oversize. :1

Re: Turning a honda crankshaft = bad???
 

dont replace what doesnt need replacing

if its working fine why ---- with it again

Re: Turning a honda crankshaft = bad???
 

He's right...honda cranks are nitrided. Usually turning them down removes this and makes the crank weaker. Worse case scenario, don't beat it, and don't rev the piss out of it.

Re: Turning a honda crankshaft = bad???
 

yup nitrided...they harden/treat the surface of the journals and then micro polish it.

Re: Turning a honda crankshaft = bad???
 

how much hp do you guys think a stock b18b crack could take?

Re: Turning a honda crankshaft = bad???
 

I've seen stock b18a/b cranks hold over 650whp. I think it would be one of the last things I'd be worrying about in your setup. It's pretty rare to see a honda crank break.

Re: Turning a honda crankshaft = bad???
 

if your worried about it just say ---- it and get a new crank d16 cranks arn't hard to find and any d16 crank should fit in your zc