ZRP Std Intake Valves Black Nitride for BMW 3.0L N55 S55

BMW 3.0L N55 / S55 – ZRP Standard Black Nitride Intake Valves (Set of 12)

ZRP Standard Black Nitride Intake Valves are engineered for the BMW 3.0L N55B30 and S55B30 twin-turbocharged inline-six engines, including applications such as M3 F80 and M4 F82/F83. Designed for high-performance street builds and demanding motorsport applications, these intake valves provide exceptional durability, dimensional stability, and consistent operation under high boost and high-RPM conditions.

Manufactured from one-piece forged high-grade stainless steel (EV8 / 21-4N), each valve undergoes a specialized black nitriding process. This advanced surface hardening treatment diffuses nitrogen into the outer layer of the valve, significantly increasing wear resistance and fatigue strength while reducing friction between the valve stem and guide thanks to the smoother, hardened surface.

Unlike localized chrome coatings, the entire valve — including both stem and head — receives the black nitrided treatment. This ensures uniform surface protection, enhanced resistance to abrasion and valve seat recession, and extended service life in modern high-output turbocharged engines.

Each valve is precision forged, CNC-machined, polished, and tip hardened to meet strict dimensional tolerances. This guarantees accurate valve seating, stable high-RPM operation, and consistent sealing performance in both naturally aspirated and turbocharged configurations.

Technical Features

• Base Material: High-grade stainless steel (EV8 / 21-4N)

• Surface Hardness: Nitrided layer up to approx. 800 HV

• Manufacturing Process: Precision forged, CNC-machined, polished, and tip hardened

• Treatment Coverage: Full black nitriding of stem and valve head

• Dimensional Accuracy: Tight tolerances for concentricity, straightness, and sealing surface finish

Advantages

• Reduced stem-to-guide friction for lower wear

• Improved stability at high RPM and high boost

• Longer service life compared to untreated stainless-steel valves

• Reliable sealing in naturally aspirated and turbocharged engines

• Suitable for high-performance street, track, and endurance racing applications

Additional Information

• Set Quantity: 12 valves

• Material: Black Nitride

• Valve Size: 32.00 mm / 4.96 mm / 105.00 mm

• Application: BMW 3.0L 24v N55 & S55 Twin-Turbo Inline-Six

• Engine Codes: N55B30, S55B30 (M3 F80, M4 F82/F83)