Supertech BMW S14 Black Nitrided Exhaust Valve - +1mm Oversize - Set of 8

These Supertech exhaust valves are black nitrided, a surface hardening process that makes the valve face more durable and resistant to wear. This set includes eight +1mm oversize exhaust valves, specifically made for the BMW S14 engine. The oversize design can help improve airflow into the combustion chamber, potentially leading to better performance, especially when rebuilding or modifying the engine's top end.

The black nitriding treatment not only increases hardness but also improves the valve's resistance to corrosion and scuffing, which is crucial for longevity in high-temperature exhaust environments. Each valve in this set is precisely manufactured to be 1mm larger in diameter than the stock exhaust valves. This is a common modification when porting cylinder heads to maximize the valve opening and improve gas flow. Installing these valves requires careful attention to valve seat machining to ensure a proper seal and optimal performance.