Wiseco 6669M855AP Professional Mitsubishi 4G63 Forged Piston 85.5mm Bore

Wiseco 6669M855AP Professional Series Forged Piston

The Wiseco 6669M855AP is a high-performance forged piston designed specifically for Mitsubishi 4G63 engines. Engineered for enthusiasts and racers demanding maximum performance and reliability, this professional-grade piston features precision manufacturing to exacting specifications.

Key Specifications

• Bore Size: 85.50mm (3.366 inches)
• Compression Height: 1.137 inches (28.88mm)
• Application: Mitsubishi 4G63 engines
• Material: High-silicon, low-expansion forged aluminum alloy

Premium Forged Construction

Wiseco pistons are forged from high-silicon, low-expansion aluminum alloy that delivers superior strength while reducing weight compared to cast pistons. This advanced material composition provides improved heat transfer characteristics and extends service life, even under demanding high-performance conditions. The forging process creates a denser, stronger piston that can withstand extreme cylinder pressures and temperatures.

Precision Manufacturing

Each piston is diamond-turned on CNC computer-controlled machining centers, guaranteeing a perfect finish with zero size variation. Computer-engineered piston skirt profiles minimize cylinder wall friction for reduced drag and improved power delivery. The lightweight forging provides instant throttle response and maximum torque output.

Performance Features

• ArmorGlide skirt coating reduces friction and increases efficiency
• Optimized ring groove design for superior sealing
• Designed to withstand high boost and extreme operating conditions
• Ideal for stroker builds and performance applications
• Precisely controlled compression height for accurate deck clearance

What's Included

This is an individual piston. Complete piston kits (which include rings, wrist pins, and circlips) are available separately. Verify all specifications against your engine's requirements before installation.

Note: This is a performance piston designed for modified engines. Professional installation and proper engine preparation are required. Consult with an experienced engine builder to ensure proper piston-to-wall clearances and ring gaps for your specific application.