Supertech Honda K20 / F20C1/F22C1 Black Nitrided Exhaust Valve - +1mm Oversize - Set of 8

These Supertech exhaust valves are black nitrided, a surface treatment that hardens the valve face and stem. This process helps improve durability and resistance to wear, especially in high-performance applications where temperatures and stresses are higher. This set includes eight valves, each measuring 1mm larger than the stock size, designed to increase the valve's sealing surface area for potentially improved airflow and combustion efficiency.

Designed for Honda K20, F20C1, and F22C1 engines, these valves are a popular choice when rebuilding or upgrading the cylinder head. The +1mm oversize is a common modification that can contribute to better cylinder filling and exhaust scavenging, especially when paired with other engine modifications. The black nitride coating also offers improved lubricity, which can help reduce friction in the valve guides.

When installing these valves, ensure your valve seats are properly machined to accept the larger diameter. This is a critical step for proper sealing and performance. This set is intended for those looking to restore or enhance the performance of their Honda engine's top end.