Wiseco Professional Series Mitsubishi Evo 4-9 4G63 Piston Set - 85.50mm Bore (+.020), 9.5:1 CR, K666M855AP

Fits 1996-2007 Mitsubishi Lancer Evolution IV, V, VI, VII, VIII, and IX (4G63).

Wiseco Professional Series forged pistons are engineered for high-horsepower Mitsubishi 4G63 builds where reliability under extreme cylinder pressure is mandatory. Forged from high-tensile 2618 aluminum alloy, these pistons feature an asymmetric skirt design to minimize friction and weight while maintaining stability at high RPM. Each piston is treated with Wiseco's ArmorGlide skirt coating to reduce drag and provide a seizure-resistant surface for increased longevity in heavy-duty racing environments.

This set includes precision-machined features such as forced pin oiling for superior wrist pin lubrication and anti-detonation grooves to protect the ring land by disrupting pressure waves. The fully machined crowns and precision-cut ring grooves ensure maximum combustion seal and consistent performance across all cylinders.

• Manufacturer Part Number: K666M855AP
• Bore Size: 85.50mm (+.020 over)
• Compression Ratio: 9.5:1
• Material: 2618 Forged Aluminum Alloy
• Skirt Coating: ArmorGlide Friction-Reduction Coating
• Includes: Premium piston rings, wrist pins, and locks
• Features: Asymmetric skirt, forced pin oiling, and anti-detonation grooves