Description
The ARP 401-4701 head stud kit is listed for BMW B58. The fasteners secure the cylinder head to the block; their application, installed length and preload must work with the chosen head and gasket arrangement.
Technical Highlights
- Manufacturer part number: 401-4701
- Application/configuration: BMW B58
- Material: Custom Age 625+
Custom Age 625+ combines high strength and fatigue resistance with resistance to atmospheric corrosion and oxidation. It is a material specification, rather than a guaranteed power or boost rating for the assembled engine.
Selection Guidance
Fastener preload supplies the clamping force at the head-to-block joint. Gasket sealing also depends on suitable deck finish, component condition and the correct assembly procedure.
Match the engine and any specified aftermarket cylinder heads or block to the listed configuration. Do not assume that related engines use the same fastener dimensions.
Installation Considerations
Trial-fit the assembly and check gasket surface requirements. Install studs hand tight. Keep washer seating surfaces dry, with the stamped washer face against the cylinder head. Apply ARP Ultra-Torque to the stud threads and underside of the nuts, following the kit-specific tightening procedure.