tuff

iTrader: (15)

I just got my parts back and i was lookin at my stuff when i got home and the guy who did the work was gone for the day.The journals are fine but the rest of the crank looks blue like burnt or they heated it up.What is that from is this normal when you cut one of these cranks.It almost looks like they put it in a oven.Any input

Thanks,Mike

mr2guru

iTrader: (16)

Nitride treated?

tuff

iTrader: (15)

Why is that is what it looks like.And if it was,why would they to that on a crank that is damm strong.Even the reluctor ring is blue.

cantdrv65

iTrader: (3)

Unfortunately you are going to ask them what exactly they did and why the crank is blue. I guess you could have a hardness test performed on it to see if the metal was compromised but I doubt they got it THAT hot unless it was actually retreated....

mr2guru

iTrader: (16)

yeah, it's blueish. Increases journal hardness for wear resistance.

http://www.key-to-steel.com/Articles/Art117.htm

cantdrv65

iTrader: (3)

The process involves heating the entire crank in an oven over a controlled temp for a certain period of time. Its done in a nitrogen atmosphere hence the term nitrided. I suppose after being cut that is a really good thing to do as it adds surface hardness....

Edit: Mr2 beat me to it....

tuff

iTrader: (15)

I don't what these engine buliders do to are stuff half the time but here are some pics.

mr2guru

iTrader: (16)

definately nitrided.... did you pay for that service?

tuff

iTrader: (15)

They never asked me if i wanted that done but its not blue all over or is that just the way it looks.I payed 140.00 for the crank to get cut and another 45 for magnaflux.Does that price sound right for nitrided to.

gun5l1ng3r

I think the fact that it is not blue all over might mean that it was subjected to an uneven heat, like you would see on a set of headers after some time.

Is it more of a rainbow or more of a blue 'anodized' color?

427

iTrader: (3)

Nitride is done to the whole crank, it is normally grey and cost is 125-160 just for that service. It spends multiple hours (I think 8) in the oven coming up to, then lowering down at a controlled rate.
That looks strange, may be some type of induction hardening.

Kurt

mrdragster1970

.

Bluing was always a sign of heat, the bad kind.

The shop I use, uses blue for magnafluxing, clean the crank and see if it comes clean. I doubt it will from the little I can see in the pics.

Can't imagine you got anything fancy for that price.

Can't tell much from Pic, but that looks weird. Heat damage of some kind??

Becareful before u put it back together, be safe & good luck.
.

tuff

iTrader: (15)

Now im kinda worryed the shop that did it sends them out.He sayed when i questiond him on this he said the shop who did the crank is a shop that briant reccomends using.And they do alot of big cube race motors.I know just because someone doe's big race motors doe's not make me belive that the crank is right.I will send it out for a second opion before my motor go's together.This just sucks and i don't wanna take any chances.

Steve - Race Eng

iTrader: (1)

As Kurt said, it looks like that crank was induction hardened to me as well.

Do yourself a favor, call Dave at Mile High Cranks in Denver. 303-781-6764

Get his e-mail and send him your photos. It could be that he did the work on your crank. I'm sure he can tell you something about it regardless.

Steve

gun5l1ng3r

Do you think it was a controlled process with uneven coloring like that?

I am by no means an expert at all, so I don't really know a lot about what processes can be dones to crankshafts, but if that was my crank, I would have it checked over before I spin that sucker to 7500RPM!

Old Geezer

iTrader: (3)

Induction hardening is done in a localized area.. In this case, the rod journals, and the mains..Thus the discoloration...

tuff

iTrader: (15)

You hit the nail on the head. That is what i found out.Thanks for all the input guys.

3pnt4maro

iTrader: (2)

glad you found out