This Supertech Intake Valve is designed specifically for the Mazdaspeed 3 and 6 MZR DISI engines. It features a 5.98mm stem diameter for stock valve guide and seal fitment but tapers to 5.5mm at the top in order to fit with the stock valve train or the Supertech upgraded springs and retainers. Uses factory OEM guides and seals only.
Our stainless steel intake valves are manufactured from an enhanced version of EV8 (21-4N) steel. We have chosen this material specifically because it’s the highest grade of steel available and provides the strength to withstand just about any application. Our exhaust valves are made from EV16 (21-8N) or EV8-Nb/w for even greater strength at higher temperatures. Our stainless steel valves are one piece forged valves, and depending on the application feature hardened tips, hardened seats, swirl polish, undercut, and our black nitride coating.
Supertech black nitride coated valves feature a harder surface area and a smoother finish, providing less friction and subsequently longer life