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FE Power Forums => FE Technical Forum => Topic started by: 482supersnake on October 14, 2021, 03:33:41 PM

Title: 427 steel crank
Post by: 482supersnake on October 14, 2021, 03:33:41 PM
If a factory steel crank is turned down to BBC rod size would it need to go through a heat treat process?
Title: Re: 427 steel crank
Post by: 482supersnake on October 14, 2021, 10:37:37 PM
Also, are Molnar rods any good?
Title: Re: 427 steel crank
Post by: pbf777 on October 15, 2021, 11:03:35 AM
............would it need to go through a heat treat process?


     It would not be considered mandatory, but, back when we used O.E.M. cranks in performance applications we would get them nitrited; this after turning, a ruff polish, heat treated, then straightened, and this would sometimes be concerning as to the sum of re-alignment required, then finish polished.    ;)

     The heat treatment facility (Sun Coast) was just down the road less than a mile from our shop which was convenient, but every once in while our stuff would come back bright marbled purple in color, I always assumed do to some contamination of the atmosphere in treatment, or it's what happens when late in the day the employee wanting to go home swings the containment door open to soon instead of waiting for the adequate cool down period.  We never experienced any issues with this, even though one was still left with the concern for inconsistency in appearance and therefor execution; but with the advent of the 4.6 Modular steel cranks, they most often appear with the same purple coloration, so what the heck!  :o

     Scott.
Title: Re: 427 steel crank
Post by: mike7570 on October 28, 2021, 03:06:07 PM
If you need a factory steel crank turned down to BBC I have one in the classifieds ready to go.
Title: Re: 427 steel crank
Post by: Gregwill16 on October 28, 2021, 03:39:26 PM
I have heard the factory hardening was only something like .020-.030 deep.
Title: Re: 427 steel crank
Post by: cammerfe on October 28, 2021, 10:16:28 PM
A caveat---nitriting and nitriding are not at all the same thing, chemically. Please notice the 'd'. The surface treatment for steel has the 'd'. :)

KS
Title: Re: 427 steel crank
Post by: pbf777 on October 29, 2021, 11:35:27 AM
    Yep, "D".  Dog-gone-it! :o   Ops, sorry for the typo, my bad! :-[   

    But at least no one could have physically gone wrong, even if they had attempted to followed my statement to the letter, as the heat treater would have understood one's intention even though you misspelled it.    ;)

    Could someone please proofread my posts, so at least the spelling is right?     ::)

    Scott.
Title: Re: 427 steel crank
Post by: Gregwill16 on October 29, 2021, 01:19:27 PM
I can't be the only one that wishes Ken had used the  ;) emoji at the end of his post  :)
Title: Re: 427 steel crank
Post by: cammerfe on October 29, 2021, 10:10:39 PM
 ;) :o ;)

Used the basic smiley to suggest my comment was not, in any way, intended to be a 'backhand'. My long-ago degree in chemistry and then my work at FoMoCo as a metallurgical process engineer makes me sensitive to something that is not-quite-correct from a chemical viewpoint.

No offense, at all, intended.

KS
Title: Re: 427 steel crank
Post by: 482supersnake on October 30, 2021, 11:45:22 AM
If you need a factory steel crank turned down to BBC I have one in the classifieds ready to go.

Thanks that's a good deal. I need to see if rods are available that would work with the pistons that I have already.