BMW M50 M52 S50 S52 Pro-Xtreme Valve Set | 5150 x Manley Performance

The Pro-Xtreme Stainless Steel Valves from 5150 AutoSport, developed in collaboration with Manley Performance, are engineered for the most severe operating conditions in BMW M50, M52, S50 and S52 engines. These single-groove, high-strength stainless steel valves are designed exclusively with a 7 mm stem to withstand the demands of high-boost, nitrous-fed and high-revving race engines.

With dimensions of 34 mm intake and 31.5 mm exhaust, these valves match upgraded cylinder head workflows for the M50 M52 S50 S52 platform. The stainless steel alloy construction ensures exceptional strength, fatigue resistance and durability under extreme combustion pressures and elevated temperatures. A precision back-cut design enhances airflow through the head, supporting greater volumetric efficiency and power potential. Hardened tips provide long-term wear resistance and maintain reliable sealing under stress.

During our in-shop development on our E36 M3 "Bully," we discovered that traditional 6 mm stem valves were failing in extreme duty applications—bending or deforming under high boost and anti-lag scenarios. By upgrading to a 7 mm stem and selecting a far superior material than factory spec, these Pro-Xtreme valves eliminate that weak-link and protect the valvetrain during aggressive builds.

Important fitment note: These valves require new valve guides and a 7 mm valve spring kit when installed in M50 Non-Vanos, M52, S50 or S52 applications, available here. Designed for serious engine builds, they are ideal for drag racing, road racing, forced-induction and nitrous applications where valvetrain durability is mission-critical.

Key Features:

• Single-groove stem design for secure keeper retention
• Stem sizes: 7 mm
• Intake diameter: 34 mm
• Exhaust diameter: 31.5 mm
• Race-grade stainless steel alloy construction for superior strength and fatigue resistance in high-RPM or boosted applications
• Back-cut under-head design to improve airflow
• Hardened tips and precision finish for reduced wear and improved sealing

Professional Installation is strongly recommended. 

BMW M50 M52 S50 S52 Pro-Xtreme Valve Set Contents: 

• (12) 34mm Intake Valves
• (12) 31.5mm Exhaust Valves