Supertech Performance NIVN-1052/SL-12 RB25 Intake Valves +1mm Oversize Black Nitride

These premium valves feature a +1mm oversize head diameter (35.15mm) for improved airflow and performance in built engines.

Key Specifications:

• Head Diameter: 35.15mm (+1mm oversize)
• Stem Diameter: 5.97mm
• Overall Length: 104.15mm (longer for solid lifter applications)
• Material: Enhanced EV8 (21-4N) stainless steel with black nitride coating
• Groove Type: Single groove
• Features: Undercut stem, back-cut face

Manufactured from one-piece forged stainless steel for maximum strength and durability, these valves undergo a specialized heat treatment process to achieve optimal hardness for high-performance applications. The black nitride coating provides a microhardness exceeding 800HV while maintaining excellent ductility in the base material. This coating creates a harder, smoother surface that reduces friction and extends valve life compared to traditional chrome coatings.

The black nitride finish is applied to the entire valve surface and adheres at a microscopic level, preventing flaking or breaking even under extreme conditions. The +1mm oversize head diameter improves volumetric efficiency, while the undercut and back-cut features optimize flow characteristics. The extended length (104.15mm) is specifically designed for solid lifter conversions, ensuring proper geometry and valvetrain function.

Supertech valves are trusted by professional engine builders in NASCAR, IRL, road racing, drag racing, and Formula One applications. Made in USA.