BMW B46 ARP Main Stud Kit

Upgrade your BMW B46 bottom end with this ARP Main Stud Kit—a crucial reinforcement for high-horsepower, high-RPM builds. ARP Main Studs replace the factory main bolts with precision-engineered hardware made from premium materials to handle extreme pressure and stress where it matters most.

Why Upgrade to ARP Main Studs on Your B46?

• Stronger, More Reliable Clamping
  OEM bolts can’t match the consistent clamping force of ARP Main Studs. This ensures precise crank alignment, improves main cap stability, and promotes long-term engine durability.
• Block Rigidity Under Boost
  ARP Main Studs increase structural rigidity across the block, helping maintain bearing alignment under high cylinder pressures. The result: more efficient power transfer, faster throttle response, and reduced distortion.
• Protect Against Main Cap Walk
  Prevent main cap movement—a common issue in high-power builds that leads to crank and bearing damage.
• Minimize Fastener Stretch
  ARP’s advanced alloys and machining resist stretching and thread fatigue even under extreme loads and sustained high RPMs.
• Preserve Your Block Threads
  With higher tensile strength and precise thread engagement, ARP Main Studs reduce the risk of pulling or damaging threads in the engine block.

Installation Instructions

1. Thoroughly clean all threaded holes in the engine block. If necessary, use an ARP thread chaser to ensure clean threads and proper engagement.
2. Inspect all studs, nuts, and washers for damage and verify proper fit, length, and dimensions before installation.
3. Install the main studs into the engine block by hand until snug. Do not overtighten.
4. Install the main caps and check for proper fit, alignment, and any binding.
5. Apply ARP Ultra-Torque Fastener Assembly Lubricant to the stud threads, nuts, washers, and washer contact surfaces.
6. Install the washers and nuts and tighten them by hand. Do not substitute motor oil or other lubricants for ARP Ultra-Torque.

7. Following the manufacturer's recommended main-cap tightening sequence, torque all main stud nuts progressively in three steps using ARP Ultra-Torque:

   Step 1: 20 ft-lbs
   Step 2: 40 ft-lbs
   Step 3: 60 ft-lbs

8. After final torque, measure the main bearing bores and verify proper size, roundness, and alignment.
9. If necessary, line hone the main bores with the ARP main studs installed and torqued to specification.
10. Verify final main bearing oil clearances before engine assembly.