ARP offers many different nuts and fasteners for a lot of different applications. Naturally, when you’re thinking about diesel performance and ARP together, you’re thinking about head studs. At times, these trucks make enough boost pressure that the factory cylinder head bolts can often stretch or lift resulting in a head gasket failure.
This is by no means uncommon. It happens every day but ARP has solutions for everyone. For instance, if you’re in a mild street truck but you want the extra insurance of a head stud, a lot of times truck owners will go with the trusted ARP 2000. These 2000 studs are trusted up to some pretty high horsepower and boost applications.
For those of you who’re really making nasty power, it’s recommended you use the 8740 Chromoly Custom Age 625+ studs. These have a much higher strength rating and are known company-wide as the “ultimate fastener material today”. With a tensile strength of up to 280,000-PSI, it seems as if these fasteners really can’t be touched.
Owner of Maverick Diesel, Paul Cato, has taken his truck that was a contender in the Outlaw Diesel Super Series and outfitted it with some of the best parts the industry has to offer. With that being said, this truck is making some ridiculous power. Over the weekend at the 2020 SunCoast Spring Shakedown, Cato managed a second-place finish in the Pro Street class.
What’s so significant? Cato’s untested truck after going through some serious wintertime changes managed to click off a 5.14 at 139-MPH besting his personal best from last year by a few miles. To make a truck that weighs just over 4,400-pounds go that fast takes clean over 1,700-horsepower. At that power level, you’re for sure going to have the best studs possible, right? Wrong.
“We do have fire rings in this engine so that does help, but we are working with the second-tier strength hardware. According to this weekend’s logs, our Stainless Diesel S485/96/1.32 turbocharger was making 83-PSI of boost regulated by two wastegates,” said Cato. “At 4,615-pounds, the 139-MPH speed calculates to 1,700-horsepower. We are ramping power in down track so, in my opinion, we’re making closer to 1,900-horsepower at the stripe.”
For reference, ARP uses several different materials depending on the application. ARP2000 covers the majority of moderate to extreme builds. ARP2000 has a martensitic crystalline structure and it has been quenched and tempered. This stainless steel was initially developed for use in steam power plants and it was designed for high-temperature environments.
It can safely be treated to a higher level, giving a much greater strength than 8740 chrome-moly. It is tempered above the “temper brittle zone” (between 500° and 700°F) temperature range and has a strength between 200,000 and 220,000 psi. Stress corrosion and hydrogen embrittlement (a process by which metals become brittle and fracture after exposed to hydrogen) are generally a non-issue as long as they are kept free of moisture and are properly lubricated.
For the Custom Age 625+, you’re looking at a newly formulated super-alloy that demonstrates superior fatigue cycle life, tensile strength, and toughness. The ARP Custom Age 625+ bolts provide complete resistance to corrosion and oxidization making it the ideal material of choice in the high strength, super-alloy applications. ARP was the first to utilize the Custom Age 625+ material in manufacturing and testing procedures. The typical tensile strength of a Custom Age bolt or stud is 260,000-280,000 psi.
I still think it is a good idea to upgrade to the stronger fastener if you’re really pushing your truck but know the ARP2000’s will work for quite some time. If you’re needing head studs or any hardware for your builds, be sure and check out the ARP website right here. For more information about parts, event coverage, and truck features, stay tuned to Diesel Army.