Supertech Performance MAEVN-2304D Exhaust Valve +1mm Oversize Black Nitride Dish

The Supertech Performance MAEVN-2304D is a high-performance exhaust valve engineered for the Mazda MZR / Ford Duratec 2.0L and 2.3L engine family. Featuring a +1mm oversize head diameter and a dish face profile, this valve is purpose-built to maximize flow and durability in performance and race applications. Sold individually — order the quantity equal to the number of exhaust valves your engine requires.

Construction & Materials:

• One-Piece Forged Stainless Steel (EV8 / 21-4N Alloy): Forged as a single piece for superior strength, fatigue resistance, and long-term reliability compared to multi-piece designs.
• Black Nitride Coating: A full-valve hardening treatment that achieves a minimum surface microhardness of 800HV. The nitrided layer bonds to the base material at a microscopic level, resisting flaking or cracking even under high-impact conditions. When combined with Supertech's stem superfinishing process, surface roughness is reduced to one-third that of a chrome-coated valve, resulting in significantly less friction between the valve stem and guide.
• Hardened Valve Tip: Each valve tip is hardened beyond 52 HRc for extended wear life.
• Stem Superfinish: Standard on all Supertech valves, the superfinish process further reduces stem surface roughness for smoother operation and reduced guide wear.

Key Specifications:

• Valve Type: Exhaust
• Head Diameter: +1mm Oversize
• Stem Diameter: 5.48mm
• Face Style: Dish
• Groove Type: Single Groove
• Material: Black Nitride Stainless Steel (EV8 / 21-4N)

Engineering & Quality:

• Application-specific design — not manufactured from generic blanks
• Strict dimensional tolerances verified with ultrasonic testing, X-ray inspection, and laser measurement equipment
• Computerized Finite Element Analysis (FEA) used in valve development
• Developed in close collaboration with professional engine builders for continuous refinement

Supertech valves are designed to deliver maximum flow rates, uncompromising dimensional accuracy, and the durability demanded by high-revving performance and forced-induction engines. Sold per valve.