VAC Motorsports ARP Head Stud Kit for BMW N55 & S55 Engines

Secure your engine build with the VAC Motorsports ARP Head Stud Kit, engineered specifically for the BMW N55 and S55 engines. Developed in collaboration between VAC Motorsports and ARP, this is not a generic retrofit solution—it is a purpose-built head stud kit designed to deliver superior clamping force, exceptional reliability, and long-term durability for high-performance and motorsport applications.

Available in both ARP2000 and Custom Age 625+ (CA625+) materials, this kit is ideal for everything from fast road builds to high-boost track and race engines. Whether you're building a tuned street car or a dedicated competition vehicle, these premium head studs help maintain a consistent head gasket seal under extreme cylinder pressures.

Unlike alternative retrofit head stud kits originally intended for other engine platforms, the VAC Motorsports kit has been specifically engineered for the N55 and S55 architecture, providing the correct fitment and material specification required for long-term performance.

Key Features

• Designed specifically for BMW N55 and S55 engines
• Developed exclusively by VAC Motorsports and ARP engineers
• Available in:
  • ARP2000 – Ideal for high-performance street and track applications
  • Custom Age 625+ – Ultimate strength for extreme horsepower and motorsport builds
• Superior clamping force to maintain head gasket integrity under high boost
• Protects engine block threads compared to conventional head bolts
• Significantly stronger than generic retrofit head stud kits
• Trusted by professional race teams and used in all VAC-built engines
• Manufactured from premium aerospace-grade materials for maximum reliability

Kit Contents

Each kit includes:

• 14 × 11mm ARP Head Studs
• 14 × ARP Hardened Washers
• 14 × ARP Aerospace-Quality Nuts

Installation Notes

N55 Engines:

To install this kit on an N55 engine block, the four existing 9mm threaded holes must be drilled and tapped to 11mm, allowing all 14 head studs to utilise the same 11mm specification.

S55 Engines:

Direct replacement installation with no engine block modifications required.

Recommended Torque Specifications

Using the supplied ARP Assembly Lubricant:

ARP2000

• Step 1: 30 ft-lbs
• Step 2: 60 ft-lbs
• Step 3: 90 ft-lbs

Custom Age 625+

• Step 1: 30 ft-lbs
• Step 2: 70 ft-lbs
• Step 3: 110 ft-lbs

Always follow the latest manufacturer installation procedures and torque sequences.

Why Choose the VAC Motorsports ARP Head Stud Kit?

When increasing boost levels or engine output, maintaining a reliable cylinder head seal becomes essential. The VAC Motorsports ARP Head Stud Kit provides significantly greater clamping force than factory head bolts, helping prevent head lift and gasket failure under demanding conditions.

This kit has been designed specifically for BMW N55 and S55 engines, eliminating the compromises associated with adapted Chrysler or Volvo stud kits. Trusted by professional engine builders and race teams worldwide, it delivers the strength and reliability required for serious performance builds.

Vehicle Compatibility

Compatible with BMW models fitted with:

• BMW N55 Engine
• BMW S55 Engine

Please verify compatibility with your specific vehicle before ordering.