ARP Bolts & Studs
More and more Diesel Power Products customers are running large single turbos or compound turbo set-ups. Many of these turbos are capable of upwards of 50PSI of boost pressure with the right fueling. ... read more
More and more Diesel Power Products customers are running large single turbos or compound turbo set-ups. Many of these turbos are capable of upwards of 50PSI of boost pressure with the right fueling. At these pressures the stock head bolts on our light duty diesel trucks are prone to stretching which can lead to head gasket failure. Head to block sealing is critical and that's where ARP Diesel Head Studs come in.
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 220,000 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. It's important to note that lesser quality studs are not even centerless ground—the 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 aligned—something that won't happen with inferior quality head studs.
ARP studs are thread rolled after heat-treat, which gives them about 1000% (that's ten times) better fatigue strength than those studs that are threaded prior to heat-treat.
Cummins Head Studs / Duramax Head Studs / Powerstroke Head Studs