Well after performing some research on the process and what to do with my build, I sent my crank out to get nitrated and knife edged. The knife edge process that I am doing is not what you would think. This is just cleaning up the edge of the counter weights. This is not machining the crank weights to a point. I will post pics once its done.

However, I have had the last few crankshafts nitrated to case harden the crank. I have not had any issues with perfming this to my stock evo crank and now Im doing it to my 2.4L crank.

Has anyone else done this? Any engine builders out there that recommend or do not recommend it?

I had them quote making a billet crank and it was $2500.

Ive seen the ones on ebay and what not go for $1000 all the way up to $3500. I know the manley/eagle ones are made in China. Im not sure about the cosworth ones.

Does anyone use a billet crank? What brand and any issues in quality?

 

My new build is going to have a K1 94mm in it. I'll keep you abreast of how it holds up.

 

nitriding (not nitrating) infuses nitrogen into the surface of the crankshaft, and the nitrogen combines with carbon to make carbo-nitrides. the process not only hardens the surface (carbo-nitrides are very hard) but also creates a compressive layer in the plane of the surface. this compressive layer can improve fatigue crack nucleation resistance and is the real benefit of nitriding. the greater hardness has no benefit because a properly heat treated crank is already way harder than the journal bearings that support it.

 

Is there any reason you want a billet crank?? I've been told from a reliable vender that stock cranks are good for 900+ WHP.

 

Forged crank would be a decent compromise, no?

 

I would disagree with statement in bold. i have been nitriding 7 bolt cranks for over ten years. 7 bolts no matter what the year has NO surface hardening from factory at all. nitriding drastcally reduces crankwalk and spun bearings.

with a stock crank if you damage the bearings and hear any audible noise the crank will no longer be round. with a nitrided crank you can swap bearings in car and be on your way again. the difference in hardness is remarkable.

 

I thought the stock cranks from the factory are induction hardened?

 

If the factory heat treat is poor quality, or the crank is made from a lower strength steel, I fully agree that nitriding will help control wear and deformation on the journals.

 

Great to know. My first and second builds I have done the nitriding process.

I was cusious of how many builders do this or even recommend it to their customers if they are a shop.

Does anyone know if Buschur, MAP, AMS, or English Racing does this?

 

Stock crank is already forged. Personally i would shot peen and nitride the OEM crank.

 

they are not. they have no hardening process done to them. they are very soft and damage easily.

the big shops dont push nitriding. they make more money not doing so.

 

To what extent is magnafluxing (MPI ) still considered an important testing process that should be carried when selecting a used factory crank for a 2.3L, or 2.4L motor build?

 

In my opinion, it should be done to any used crank being carried over into another build.