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FE Power Forums => FE Technical Forum => Topic started by: bobb428 on April 19, 2012, 08:23:31 PM

Title: Shelby head stud torque?
Post by: bobb428 on April 19, 2012, 08:23:31 PM

Jay, what are the torque specs on the Shelby head studs?

Title: Re: Shelby head stud torque?
Post by: jayb on April 19, 2012, 08:57:12 PM

I use 110 ft-lb on the long ones and 100 ft-lb on the short ones.

Title: Re: Shelby head stud torque?
Post by: bobb428 on April 19, 2012, 11:00:20 PM

Thanks

Title: Re: Shelby head stud torque?
Post by: Barry_R on April 21, 2012, 08:35:16 PM

I'd be tempted to go the other way around - the shorter bolt would have a higher yield torque...think of a fastener as a spring.

Both values are higher than I use on aluminum/aluminum applications - I normally run around 95 with ARP lube.  I'm concerned about block & head growth increasing the clamp loads.  No real "right" answer - just different schools of thought.  Like comparing blonde to red....I'm speaking of beer of course....

Title: Re: Shelby head stud torque?
Post by: jayb on April 21, 2012, 10:48:28 PM

You got me thinking a little on this, Barry, so I went and checked a couple of sources.  Edelbrock says 110 on the top (long) bolts and 100 on the bottom bolts, and that is probably where I got my numbers.  The Shelby literature says 95 on all of them.  Shelby also specifies a moly assembly lube on the threads.  I've been using ARP's new Ultra-lube, which has a significantly different coefficient of friction than their old moly lube, and according to my machine shop requires higher torque values to get the same fastener stretch.  Hmmmmm, as you said, probably no single right answer...