Wiseco K670M8950 Piston Kit Nissan QR25DE 2.5L 16V 89.50mm Bore

The Wiseco K670M8950 is a forged piston kit designed for the Nissan QR25DE 2.5L 16-valve four-cylinder engine. Wiseco pistons are manufactured using aerospace-quality 2618 alloy forgings, offering superior strength and thermal properties compared to cast OEM pistons — making them a popular choice for performance builds and engine rebuilds.

Key Features:

• Bore Size: 89.50mm (stock bore is 89.00mm — this kit is sized for a standard overbore)
• Engine Fitment: Nissan QR25DE 2.5L 16-valve DOHC inline-4
• Construction: Forged 2618 aluminum alloy for high strength and durability
• Piston Design: Flat-top or dish configuration optimized for QR25DE combustion chamber geometry
• Ring Grooves: Precision-machined for proper ring seal and oil control
• Wrist Pin: Full-floating design included for reduced friction and improved reliability
• Coating: ArmorGlide skirt coating reduces friction and wear during break-in and normal operation

• Full-floating wrist pins
• Piston rings
• Wrist pin locks (circlips)

Wiseco has been a trusted name in high-performance pistons since 1941, supplying professional racing teams and engine builders worldwide. The K670M8950 kit is engineered to meet or exceed OEM tolerances while providing the added strength needed for modified or high-mileage engine applications. Professional installation and proper clearancing by a qualified machine shop are recommended.