<VV>Turning a crank

[Tony Underwood]

At 06:52 PM 11/3/2006, Padgett wrote:

>>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.


Then again, when done right (and checked out) a crank turned .010 is 
not going to suffer any adverse effects from the process, and in fact 
is for all intents and purposes as fresh as it's ever gonna 
get.   It's worth mentioning that even turned .030 which is about the 
limit of undersize bearings you're likely to find,  the difference in 
size from metal removed is impossible to detect with the 
eye...  gotta break out the mics to tell for sure.

A .030 turndown is about as thick as a dime.     Turning a crank .010 
removes about a matchbook cover's worth.


For sake of simplicity and available "std" parts, an uncut crank is 
of course desirable, but I'd still be fine with running a crank 
turned as much as .030 any day.   It's just not that much metal that 
gets taken off.


Even a cut crank can get returned to std by welding and then, for 
"fine tuning", by chroming if you like...   if your budget can 
tolerate it...  ;)    It's all only money.    Of course, if bux 
aren't an issue, you could get Ray to carve you out one of his billet 
cranks.

Pretty...  shiny...  I wants one...


tony..