BMW S58 ARP 625+ Custom Age Main Stud Kit

ARP S58 625+ Custom Age Main Stud Kit

When we started developing our S58 Billet Main Cap system, we needed a main stud strong enough to handle the extreme loads of high-horsepower S58 builds. Our friends at NRW had the same need for their S58 Billet Block project, so we teamed up to develop a solution that would benefit the entire S58 performance community.

Manufactured from ARP 625+ Custom Age material, these high-strength main studs provide exceptional tensile strength, fatigue resistance, and consistent clamping force for extreme-power applications. 

This ARP Main Stud Kit is designed to replace BMW part number 11118604584 for the BMW S58 engines found in high-performance models such as G80/G81/G82/G83 M3/M4, X3M F97, and X4M F98. 

Features & Benefits

• ARP 625+ Custom Age material
• Increased strength and fatigue resistance
• More consistent main-cap clamping
• Helps minimize main-cap movement under extreme loads
• Improved crankshaft and main-bearing alignment
• Ideal for high-RPM and high-horsepower S58 builds
• Direct replacement for BMW OEM main bolt part #11118604584
• Designed for use with 5150 AutoSport Billet Main Caps and NRW S58 Billet Blocks

When opting for main studs instead of factory bolts, it's important to note that the engine builder should mic the bores. Using studs may require a line hone to ensure proper fitment and alignment. A line hone is a machining process that can be used to resize and reshape the main bearing bores, ensuring that they are perfectly round and concentric. This is crucial for ensuring proper oil clearance and preventing premature bearing wear. By mic'ing the bores and performing a line hone if necessary, engine builders can ensure that the main studs are installed correctly and that the engine will perform reliably and at its best.