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

Supertech Performance NIVN-1052-12 intake valves are precision-engineered for Nissan RB25 24V DOHC engines equipped with hydraulic lifters. These high-performance valves are manufactured from a single piece of forged stainless steel 21-4N material, delivering exceptional strength and durability for demanding racing and performance applications.

Key Features:

• Black nitride coating for superior wear resistance and reduced friction
• +1mm oversized head diameter at 35.15mm for improved airflow
• Stem diameter: 5.97mm for precise fitment
• Overall length: 103.55mm optimized for hydraulic lifter applications
• Single groove design for reliable valve keeper retention
• Undercut and back-cut for enhanced flow characteristics
• Forged from premium stainless steel 21-4N (enhanced EV8 steel)

The black nitride surface treatment provides a microhardness of 800HV minimum while maintaining excellent ductility beneath the hardened layer. This advanced coating offers a smoother surface finish compared to chrome-coated stems, reducing wear on valve guides and extending service life. Each set includes 12 valves to service a complete RB25 engine. Designed and manufactured for high-performance street and racing engines that demand maximum reliability and flow.