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ARP head stud questions...



On 7/30/06, LEF <rocco16@sbcglobal.net> wrote:
>
>
> Doesn't matter what type of fastener you are using, you must achieve a
> certain clamping force to keep the head/block together.
> Aluminum heads or iron heads; doesn't matter...you aren't screwing the
> bolts/studs into the head, you are screwing them into the cast iron block.



You're wrong - aluminum and cast iron have different expansion rates
when heated.  ARP bolts are torqued to 75% of their yield strength, so
the recommended 5 ft/lb difference between the torquing aluminum and
cast iron heads must make up for the different expansion rates to keep
the stress on the studs within specs when everything is up to
temperature...


> See my other post on this subject; I don't think 70ft/lbs is nearly what the
> design engineers had in mind.
> I'd get more information before I fired that baby up......


So you're saying I shouldn't go with ARP's own recommendations?  I
fail to see the logic there...

Later,

Mark.
75
82
82 Caddy
93 Chevy/Kia 1/2 ton