ZRP Std Intake Black Nitrided Valves for Audi VW Volkswagen 1.8T 20V

Audi / VW 1.8T 20V – ZRP Standard Intake Black Nitrided Valves (Set of 12)

ZRP Standard Intake Black Nitrided Valves are engineered for Audi, Volkswagen, Škoda, and SEAT 1.8T 20V engines, delivering excellent durability, precise valve control, and reliable performance in both street and motorsport applications. Manufactured from one-piece forged high-grade stainless steel, these intake valves are treated with a specialized black nitriding process to significantly improve wear resistance and fatigue strength.

The black nitriding process diffuses nitrogen into the surface layer of the valve, creating a hard, low-friction surface that reduces stem-to-guide friction and improves lubrication stability. Unlike localized chrome coatings, the entire valve—including both the stem and valve head—receives the black nitrided treatment, ensuring uniform protection and long service life.

Each valve is precision forged, CNC-machined, polished, and tip hardened to achieve tight dimensional tolerances and maximum durability. This results in consistent sealing, smooth operation at high RPM, and reliable performance in both naturally aspirated and turbocharged engines.

Technical Features

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

• Surface Hardness: Black nitrided layer with hardness up to approx. 800 HV

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

• Treatment Coverage: Full black nitriding of the entire valve (stem and head)

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

Advantages

• Reduced stem-to-guide friction for lower wear and improved high-RPM stability

• Significantly longer service life compared to untreated stainless-steel valves

• Reliable sealing in both naturally aspirated and turbocharged engines

• Suitable for high-performance street builds and motorsport applications where durability and consistency are critical

Additional Information

• Set Quantity: 12 valves

• Material: Black Nitride

• Valve Size: 26.90 mm head / 5.96 mm stem / 105.10 mm length

• Engine Compatibility: All Audi / VW 1.8L 20V engines

• Applications:
  Audi 1.8T 20V (S3, A3, A4)
  Škoda 1.8T 20V (Octavia)
  SEAT 1.8T 20V (Leon)
  VW 1.8T 20V (Golf, Polo)