Wiseco K650M865AP Forged Pistons for 02-06 RSX-S/06-11 Civic Si K20A/Z

Vehicle Fitment

• 2002-2006 Honda RSX-S (K20A/Z 2.0L I4)
• 2006-2011 Honda Civic Si (K20A/Z 2.0L I4)

Features

• High-strength 2618 forged aluminum for extreme performance builds
• +0.50 mm (86.50 mm) oversize bore for rebuilt or bored blocks
• 10.5 cc dome design for ~12.3-12.4:1 compression ratio in stock block
• ArmorGlide® skirt coating for friction reduction and wear resistance
• Precision ring grooves and anti-detonation features
• Strutted forging for improved piston stability
• Designed for high-rev, high-load sport compact engines
• Includes premium piston rings, wrist pins, and locks for complete rebuild

Specifications

• Bore diameter: 86.50 mm (+0.50 mm oversize)
• Compression height (CH): 30.00 mm
• Dome volume: 10.50 cc
• Piston material: 2618 forged aluminum
• Wrist pin diameter: 22 mm (0.866 in)
• Piston count: 4
• Ring set included: Yes
• Applicable engines: Honda K20A and K20Z 2.0L I4

Included Components

• 4x forged pistons (86.50 mm)
• 4x piston rings
• 4x wrist pins
• 4x snap rings/locks

Product Description

The Wiseco K650M865AP forged piston kit is designed for enthusiasts and builders pushing Honda K-Series engines to their limits. These pistons are forged from premium 2618 aluminum and engineered for sport compact performance, ensuring exceptional strength and durability in high-rpm and high-load environments. With an oversize 86.50 mm bore and 10.50 cc dome profile, this kit yields a performance-oriented compression ratio (~12.3:1) when used in a properly bored Honda K20A or K20Z block, making them ideal for rebuilds, boosted engines, or custom race builds.

Each piston features Wiseco's ArmorGlide® skirt coating to reduce friction and wear, along with precision-machined ring grooves and strutted forging for enhanced component integrity. The complete set includes premium rings, wrist pins, and locks, providing everything needed for a complete piston upgrade. These forged pistons are a popular choice for 2002-2006 Honda RSX-S and 2006-2011 Honda Civic Si builds where reliability and performance are critical.