Supertech Mazda Miata 1.8L Black Nitrided Exhaust Valve - +1mm Oversize - Set of 8

If you're rebuilding the top end of your Mazda Miata's 1.8L engine, especially if you're looking to improve airflow or replace worn components, these Supertech exhaust valves are a solid option. This set includes eight valves, each designed to be 1mm larger than stock. This oversize design can help increase the valve's sealing surface area, potentially improving cylinder sealing and performance when paired with appropriate head work.

These valves feature a black nitrided surface treatment. This process hardens the valve face and stem, making it more resistant to wear and heat. The nitriding also creates a smoother surface, which can reduce friction in the valve guide and improve oil retention. They are well-built for the demands of an engine rebuild, offering a good balance of performance and durability for your Miata.