<VV>Turning a crank

[Padgett]

>what is  done when a crankshaft is
>turned?

Metal is removed until the crank is smooth. The less the better. The 
hardening is only about .005" deep so turning even .010" removes all of it. 
Generally no more then .030 is removed

You might ask if polishing it will do the trick. This is similar but only 
.001-.003 is removed. Personally, I would rather replace a crank with a 
good original than have one turned even .010.

Might want to check what undersize bearings are available first. Clarks 
(page 26) shows .001, .002, .010, .020, & .030 though sounds like there are 
limitations for the .001 and .030.

Padgett