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Tip For Those With RaceWare Head Studs
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Smoothie  



Joined: 01 Jan 2003
Posts: 8030
Location: DE (the one near MD, PA, NJ)

PostPosted: Mon Jul 21, 2008 10:00 am    Post subject: Reply with quote

Very cool Steve - except for the fact that I'm on a new page, we seem to be on the same page.

With a bit more web searching and reading, I've found more terms relating to this stuff..
Apparently another term equivalent to "clamping force" and "tensile force", is "tensile load". These change with changes in torque.
[still reading...
"Tensile strength" is as mentioned before - the breaking point.
tension point before breakage = "Ultimate Tensile Strength" (aka- UTS, and equivalent to tensile strength)
tension point before permanent deformation begins = "Yield Strength"
stretching load = "tensile load"
60% of tensile strength = "shear strength"
95% of yield strength = "proof strength" (torque values are based on proof strength)]
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flosho  



Joined: 01 Jul 2004
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Location: Eau Claire, Wisconsin

PostPosted: Mon Jul 21, 2008 11:05 am    Post subject: Reply with quote

So how do we determine what the Fastener Tensile Strength(and the tq specs) of the head studs, if there is no paperwork in the box.


*edit* From what I can tell in ARP's catalog, head studs are rated at the 190k/200k FTS, which is 86 ft/lbs with ARP assembly lube.
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Smoothie  



Joined: 01 Jan 2003
Posts: 8030
Location: DE (the one near MD, PA, NJ)

PostPosted: Mon Jul 21, 2008 11:48 am    Post subject: Reply with quote

Have a look at their tech catalog - http://video.arp-bolts.com/catalog/ARPCatalog.pdf
"Pro Series" head studs are 200,000psi (pg.36).
Page 24 of that shows for a 12mm stud -
170-180k psi TS....77ft-lb w/ARP Moly (97ft-lb w/30wt.oil) for a preload of 15,540
190-200k psi TS....86ft-lb w/ARP Moly (109ft-lb w/30wt.oil) for a preload of 17,483 (verification that 86ft-lb is the torque to use (w/ARP Moly))
220,000 psi TS......96ft-lb w/ARP Moly (122ft-lb w/30wt.oil) for a preload of 19,425
Head stud installation instructions are on pg. 40.

[edit - obviously you'd already looked and typed while I was still looking )
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flosho  



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Location: Eau Claire, Wisconsin

PostPosted: Mon Jul 21, 2008 12:20 pm    Post subject: Reply with quote

The confusion(for me at least) was because they have 3 different ratings for their bolt/stud kits but don't explicitly state whats what.

I believe the ARP head BOLTS are 170/180k while the STUDs are 190/200k, and then the stainless are 220k.
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bass gt  



Joined: 02 Dec 2004
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PostPosted: Mon Jul 21, 2008 12:23 pm    Post subject: Reply with quote

flosho wrote:
The confusion(for me at least) was because they have 3 different ratings for their bolt/stud kits but don't explicitly state whats what.

I believe the ARP head BOLTS are 170/180k while the STUDs are 190/200k, and then the stainless are 220k.


Yep. This is why is said the trq setting is 85 with the ARP lube.

Steve
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