Supertech Performance MAIVN-2304D Black Nitrided Intake Valve +1mm Oversize Dish Face

The Supertech Performance MAIVN-2304D is a high-performance Black Nitrided intake valve engineered for Mazda MZR and Ford Duratec 2.0L and 2.3L engines. This valve features a +1mm oversize 36mm head diameter with a dished face profile, a 5.48mm stem diameter, and a standard length of 103.40mm — making it a popular upgrade choice for performance builds, forced induction setups, and high-revving naturally aspirated applications.

Key Specifications:

• Head Diameter: 36mm (+1mm oversize)
• Stem Diameter: 5.48mm
• Length: 103.40mm (Standard)
• Material: EV8 (21-4N) One-Piece Forged Stainless Steel
• Finish: Black Nitride coating (full valve coverage)
• Face Type: Dish
• Groove Type: Single Groove
• Valve Type: Intake
• Tip Hardness: 52 HRc minimum
• Stem Microhardness: 800HV minimum nitrided layer

Black Nitride Advantage:

• Nitrided layer is bonded to the base material at a microscopic level — it will not flake or crack under high-stress impacts
• Applied to the entire valve (not just the stem), providing complete surface protection
• Produces a smoother surface finish than chrome-coated valves, reducing friction between the valve stem and guide
• When combined with Supertech's stem Superfinish process, surface roughness is reduced to one-third of a chrome-coated valve
• Reduces power loss at high RPM by minimizing valve-guide friction

Construction Quality:

• One-piece forged construction using EV8 (21-4N) stainless steel alloy for maximum strength and fatigue resistance
• Stem undercut and swirl-polished finish included as standard
• Each valve tip hardened beyond 52 HRc for long-term durability
• Manufactured to strict dimensional tolerances verified with ultrasonic testing, X-ray inspection, and laser measurement equipment

Sold individually (per valve). For an 8-valve engine, order a quantity of 8. For best results, pair with Supertech valve springs and valve stem seals during installation.