Wiseco K573M865AP Forged 86.5 mm +8 cc Pistons for Honda / Acura K-Series

Vehicle Fitment

• Honda / Acura K-Series (e.g., K20A, K20Z)
• Acura RSX Type-S / Type-R (K20 engine)
• Honda Civic Si (K20, various years)

Features

• Forged from 2618 aerospace-grade aluminum for high strength and fatigue resistance
• +8 cc dome design to increase compression for performance builds
• ArmorGlide® skirt coating to reduce friction and extend durability
• Strutted forging geometry for added rigidity in high-stress conditions
• Fully machined crown with precise ring groove design
• Forced-pin oiling for reliable lubrication even at high RPM
• Includes premium high-performance piston ring set
• 22 mm floating wrist pins for strong and stable piston-to-rod connections

Specifications

• Bore: 86.50 mm
• Compression Height: 30.00 mm
• Dome Volume: +8.00 cc
• Wrist Pin Diameter: 22 mm
• Piston Material: Forged 2618 aluminum
• Piston Weight: ~330 g each
• Estimated Compression Ratio: ~11.7:1 (depending on head and gasket)

Included Components

• 4x forged dome pistons (86.5 mm, +8 cc)
• 4x 22 mm floating wrist pins
• 4x circlips / locks for wrist pins
• 4x high-performance piston ring sets

Product Description

The Wiseco K573M865AP piston kit is engineered for high-performance Honda and Acura K-series engines, especially those using K20A and K20Z variants. With an 86.5 mm bore and a +8 cc dome, this kit increases static compression - making it ideal for naturally aspirated builds that demand strong throttle response and high RPM performance.

These pistons are forged from 2618 alloy to deliver excellent strength and resilience under stress. The ArmorGlide-coated skirts help reduce friction and wear, while the strutted forging design reinforces the pistons under high load. The package includes matched ring sets and 22 mm floating wrist pins to ensure solid sealing and stable rod connection.

For installation, it's important to verify bore-to-wall clearance, ring gaps, and deck height to dial in the optimal compression ratio. This piston set is ideal for performance builders, race engines, or track-focused K-series builds seeking both strength and high-compression capability.