Stainless Steel Black Nitride Exhaust Valves
Supertech\'s Black Nitride exhaust valves are manufactured from premium EV8 (21-4N) stainless steel and finished with a proprietary Black Nitride surface treatment. This coating provides superior hardness, reduced friction, and enhanced corrosion resistance compared to standard stainless valves.
Each valve is precision-machined to OEM tolerances and undergoes rigorous quality control including dimensional inspection, hardness testing, and surface finish verification. The result is a valve that delivers consistent, reliable performance in both street and competition applications.
Key Features
- EV8 / 21-4N stainless steel base material for high-temperature strength
- Black Nitride surface treatment for reduced friction and wear resistance
- Precision-ground stem and face for optimal sealing
- Swirl-polished underhead for improved exhaust flow
- Compatible with standard valve guides and seats
- Available in standard and oversize diameters
Applications
Ideal for naturally aspirated, turbocharged, and supercharged engines where exhaust valve durability is critical. The Black Nitride coating excels in high-EGT environments and is particularly well-suited for engines running lean air-fuel ratios or aggressive ignition timing.






