ARP head bolts

[rabbitman]

But then there are the arp studs made for 11mm gassers which will also work for 11mm diesels, then the cosworth 12mm studs that weren't really for these diesels but happen to fit and finally they came out with 12mm studs designed for our 12mm diesels.

[southernman]

the ARP2000 diesel studs are INDEED different than the gasser studs.. like, made from a different alloy..
[/quote]

That's interesting, since I spoke directly with ARP's engineers. Not trying to be argumentative, but he laughed when I asked him to tell me the difference, since, there was no difference (his words, not mine). They're made from 8740 Chrome Moly steel, and carry the same 220K psi rating... Either way, I doubt, for a mild commuter you can go wrong with studs.

Also, just for further clarification, here's a link to ARP with an application run down that seems to indicate the 2000 series studs can be used in gas or diesel - turbo and non-turbo alike. It includes the JK designator, like on my engine and includes the AAZ all in one application...

http://arp-bolts.com/images/releases/pdfs/Release34.pdf

Southernman

[R.O.R-2.0]

the ARP2000 diesel studs are INDEED different than the gasser studs.. like, made from a different alloy..

That's interesting, since I spoke directly with ARP's engineers. Not trying to be argumentative, but he laughed when I asked him to tell me the difference, since, there was no difference (his words, not mine). They're made from 8740 Chrome Moly steel, and carry the same 220K psi rating... Either way, I doubt, for a mild commuter you can go wrong with studs.

Also, just for further clarification, here's a link to ARP with an application run down that seems to indicate the 2000 series bolts can be used in gas or diesel - turbo and non-turbo alike. It includes the JK designator, like on my engine and includes the AAZ all in one application...

http://arp-bolts.com/images/releases/pdfs/Release34.pdf

Southernman


[/quote]

ok, well, if there the same studs as what weve been running, then why are they 2 prices?

why does ARP make the names different? and applications different, if its still the same stud?

glad to know that they ARE INDEED the same.

[fatmobile]

 I've had good luck with the 11mm head studs,
 in both the 1.6 and 1.5 VNT Rabbits.
 They have been worked hard and held real well.

 So I'm thinking the 12mm cosworth studs are plenty good, no need for the special 2000 studs.
 Maybe on a TDI that is putting out crazy power, but not the 1.6.

[bgbmxer]

can get them off the summit racing site just give them the part number i think i payed 170

[RadoTD]

According to ARP's website, ARP 2000 is different than 8740 Chrome Moly. Plus, 8740 doesn't have 220k psi tensile strength. Basically, if they hardened 8740 as much as ARP 2000, the threads would end up shearing off.

This all being said, it would be a fairly minimal difference

http://arp-bolts.com/pages/technical_metallurgy.shtml

19. What exactly is ARP2000 and how does it compare to 8740 and 4340?
ARP2000 is a heavily alloyed martensitic quench and temper steel, initially developed for use in steam power plants. As such it has excellent stability at high temperatures. But most important, ARP research discovered that in addition to temperature stability it has excellent notch toughness in the higher strength ranges and is alloyed to be tempered to Rc44/47. 8740 and 4340 can be tempered to the same hardness. But, the tempering temperature would yield material in the “temper brittle zone” (between 500° and 700°F), producing significant notch sensitivity. ARP2000 is tempered above that temperature range and has a strength between 200,000 and 220,000 psi.

[colhel59]

Do you have to retorque the studs after warming the engine up with arp studs? When I put mine in I don't recall them tellintg me that

[RadoTD]

It doesn't say to do that, but I retorqued mine about 500km after my rebuild and nothing budged. I'm going to do it again soon (5000km after rebuild) but don't expect anything to budge. Just in case though, it's never a bad idea

[fatmobile]

With studs you can back them off about 30 degrees and retorque them.