Re: Crankshaft hardening specification

[Dave Biggs <D.Biggs@domain.elided>]

Tim Buja wrote:
> 
> I'm having my crankshaft ground down to .010" undersize, and I've received
> a number of suggestions that I should have the crank re-hardened to ensure
> that it will last more than a few hundred miles.  Does anyone have the
> hardening spec handy so that my engine rebuilder can get it right the
> first time?
> 
> BTW, I'm using stock (Vandervell) crank and rod bearings, .010" undersize,
> if that makes a difference in the spec.

I don't know the full technical spec but I just asked for my crank to be
tuftrided which I gather is the best process for a Stag crank. Evidently
the casting material is not suitable for nitriding.

It cost me about 30 UKP but I had to do the final lapping of the
journals with oil soaked wet & dry just to polish them up a bit. However
they still looked a dark grey colour afterwards. I figured if you polish
them to shiny metal them you've just polished the hardened surface off !

Hope this helps,

Dave.
-- 
	Dave Biggs                       
	Senior Design Engineer 	
	Fujitsu Telecommunications Europe Ltd, 
	Birmingham Business Park,Solihull Parkway, Birmingham, B37 7YU.
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