The ARP 247-4206 Diesel Head Stud Kit from XDP lets you upgrade your 3.9L 4BT Diesel engine so it can withstand anything you throw at it. It’s a proven fact that OEM head bolts are the weak link in a diesel engine; especially if the engine has been modified. That’s because most engines are typically assembled from the factory using Torque-To-Yield (TTY) bolts and preloaded to yield and beyond (typically 100-110%). Any increases in combustion pressure can lead to problems like blown head gaskets or catastrophic engine failure. Furthermore because TTY bolts are yielded by design, they should not be re-used.
It is for good reason that virtually every top professional engine
builder relies on ARP head studs for their all-out competition
powerplants. ARP is the industry leader and builds heavy-duty head studs and fasteners for a wide variety of popular diesel applications. Using head studs instead of standard bolts provides your engine with the clamping force required to keep your cylinder head from lifting due to higher combustion pressures. For the ARP 247-4206 Head Studs, ARP starts with a premium grade ARP2000 alloy that is rated far superior to aircraft quality alloy steels. ARP2000 is an alloy steel that can be safely heat treated to a higher level, producing a greater strength material than Chrome Moly 8740. While 8740 and ARP2000 share similar characteristics, ARP2000 is capable of achieving a higher clamp load at 220,000 psi.
Each stud is first placed vertically into special racks and precisely heat-treated. This ensures complete heat penetration, and the results are far superior to lower quality studs from other manufacturers that just dump pieces in a basket and hope for the best. ARP head studs then travel through a centerless grinding process to ensure that they are perfectly concentric. The thread rolling operation is also done after the heat-treatment, which gives them about 2000% (that’s 20 times) better fatigue strength than studs that are threaded prior to heat-treat. It costs a lot more to do it this way, because it’s tough on tooling, but the results are worth the additional effort. Fasteners are then shot-peened to remove any surface irregularities and improve overall external integrity. A black oxide coating is applied as the final step for long lasting corrosion resistance.
Features:
- Proprietary ARP 2000 Material
- Rated At 220,000 Psi Tensile Strength
- Includes Chrome Moly Steel 12-Point Nuts
- Black Oxide Coating For Added Corrosion Resistance
- Centerless Ground To Ensure They Are Perfectly Concentric
- Improved Clamping Force Prevents Cylinder Heads From Lifting
- Broached Stud Ends Install & Make Cylinder Head Removal Easier
- Heat-Treated Prior To Thread Rolling And Machining For Optimum Fatigue Strength
- Shot-Peened To Remove Any Surface Irregularities And Improve Overall External Integrity
- Hardened Parallel Ground Washers For An Even Load Distribution And Accurate Torque Readings
- Comes With 0.5oz Of ARP Assembly Lubricant
XDP Thread Cleaning Chasers (Sold Separately):
The
XDP Thread Cleaning Chasers XD40125TC (For Head Studs) & XD40128TC
(For Rocker Arm Pedestal Bolts) are an excellent add-on that should be
used prior to installation of this kit. Using Thread Cleaning Chasers
ensures that you are able to properly clean the threads in your engine
block before the installation and torquing of the head studs. Clean
threads will provide you with accurate torque readings which are
critical during your head gasket repair, or engine build.
Disclaimer: XDP is in no way affiliated with Cummins or any of its subsidiaries or related companies, and that Cummins has not authorized the sale of any of XDP's parts, and has not tested or approved any of XDP’s parts for use in genuine Cummins brand products.