Wiseco K668M8525 Mitsubishi 4G63T EVO HD2 Asymmetric Skirt Gas Ported Forged Piston Set 85.25mm Bore

The Wiseco K668M8525 is a Professional Series forged piston set engineered specifically for the Mitsubishi 4G63T turbocharged engine found in the Evolution platform.

These pistons utilize Wiseco's advanced HD2 Asymmetric Skirt design with gas porting, a construction method that optimizes the strength-to-weight ratio while reducing friction and improving ring seal under high boost and high-load conditions. Each piston is forged and machined in the USA from 2618 high-strength aluminum alloy, delivering superior tensile strength and fatigue resistance compared to cast alternatives.

Key Features:

• Bore Diameter: 85.25 mm (+0.010 in. over standard)
• Compression Ratio: 10.5:1
• Compression Height: 34.87 mm (1.373 in.)
• Pin Diameter: 22 mm (0.866 in.)
• Stroke: 88 mm (3.465 in.)
• Rod Length: 150 mm (5.900 in.)
• HD2 Asymmetric Skirt geometry for reduced friction and improved stability
• Gas Ported crown for enhanced ring seal under boost
• ArmorGlide® Skirt Coating — seizure-resistant, friction-reducing, quieter operation
• 2618 aluminum alloy construction for improved tensile strength and thermal resilience
• Fully machined crown with precision ring grooves
• Engineered, forged, and machined in the USA at Wiseco's Mentor, Ohio facility

Wiseco's Professional Series pistons represent the top tier of their piston lineup, designed with no-compromise features for serious racers and engine builders. The K668M8525 is ideal for high-boost 4G63T builds on the Mitsubishi Lancer Evolution where factory or lesser aftermarket pistons fall short.