ARP's Custom Age 625 Plus material is newly formulated super-alloy demonstrates superior fatigue cycle life, tensile strength and toughness - with complete resistance to atmospheric corrosion and oxidation. ARP is the first to develop manufacturing and testing processes for fasteners with Custom Age 625+. Best of all, it is less expensive and expected to soon replace MP-35 as the material of choice in the high strength, super-alloy field. Typical tensile strength is 260,000 psi.
Because of the many head lifting issues on 4G63 blocks running in excess of 35+ PSI, a stronger stud needed to be manufactured to meet the demands of today's top engine builders and racers alike. No Modification to your cylinder head or block is required as these are a direct drop-in replacement for the OEM head stud!
Obtaining the optimum cylinder head-to-block sealing is especially critical in small displacement engines employing high compression pistons or power adders like turbochargers, nitrous oxide and superchargers. Thats why ARP® head studs are popular among leading Sport Compact/Import racers. You should know that ARP® uses a premium grade 8740 alloy that is rated far superior to "aircraft" quality. Then, each stud is precisely heat-treated to 200,000 psi. Following heattreat, each stud is centerless ground to make it as close to perfectly concentric as possible. This procedure involves about ten very slight cuts and results in an exceptionally straight part. Its important to note that lesser quality studs are not even centerless groundthe material is thread rolled in bar stock form (mostly before heat-treat, when the material is easier to machine). Because ARP® studs are manufactured to such exacting tolerances, you will note that gaskets and cylinder heads literally glide into position and are perfectly alignedsomething that wont happen with inferior quality head studs. ARP® studs are thread rolled after heat-treat, which gives them about 1000% (thats ten times) better fatigue strength than those studs that are threaded prior to heat-treat. Premium parallel ground washers and Hex nuts (10 each) are also included with each kit. ARP is the leader in fasteners for racing and high performance. More winning teams use ARP fasteners than all others combined. Top quality, exact tolerances, the best materials and machining processes, and the ability to survive the rigors or racing and get you in the winner's circle make ARP fasteners the #1 choice.
These ARP main studs are made from 8740 chromemoly steel and have a 190,000 psi tensile-strength rating. They are precision centerless-ground and thread-rolled to Mil-S-8879 specs, with a black oxide finish for corrosion resistance. The kits come complete with hardened washers and high-strength 12 point nuts.
ARP - The world leader in fastener technology has just released a new Pro Series ARP2000 main stud kit for 2008 and later Mitsubishi 2.0L (4B11) Turbo and Non Turbo applications.
Part No. 207-5403 - includes a set of ten, M10 ARP2000 main studs, a set of ten, M8 ARP2000 main studs, twenty 8740 chromemoly steel 12 pt nuts and a 1/2 oz. pack of ARP Ultra-Torque fastener assembly lubricant.
All Pro Series ARP2000 studs are centerless ground, heat treated prior to thread rolling and machining, and are nominally rated at 220,000 psi. These fasteners deliver a 50% increase in tensile strength over the OEM main bolts.