CP Pistons SC70458-4 87.5mm 9.7:1 Forged Piston & Ring Set for 02-06 Acura RSX

Vehicle Fitment

• 2002-2006 Acura RSX Base / Type-S (K20A / K20A2 / K20A3)
• 2001-2006 Honda Civic Type-R (K20A)

Fitment Notes

• Use only for K20A family engines; not compatible with K24 or other non-K20 variants
• Standard (STD) size; oversize rings not included unless noted
• Not CARB-legal; may be restricted in jurisdictions requiring emissions compliance such as California
• Verify valve clearance and compression height before installation

Features

• Forged high strength aluminum designed for performance
• Flat top design suitable for naturally aspirated applications
• Deep valve reliefs to accommodate high lift camshafts and oversized valves
• Custom skirt profile and barrel design to reduce skirt drag and improve stability
• Accumulator grooves for better ring seal under load
• High performance ring set included (top / second / oil ring)
• Fully CNC machined parts, all pistons balanced to ±1 gram
• Double pin oilers force fed from oil ring groove

Specifications

• Bore Size: 87.50 mm
• Compression Ratio: 9.7:1
• Piston Material: Forged aluminum
• Compression Height: 1.181 inches (30.00 mm)
• Piston Head Volume: -3.3 cc
• Wrist Pin Style: Press-fit or floating
• Wrist Pin Diameter: 22 mm
• Wrist Pin Length: 139.99 mm
• Balancing Tolerance: ±1 gram per piston
• Finish & Machining: Fully CNC'd, deep reliefs, high lift / oversized valve compatible

Included Components

• 4x Forged pistons (SC70458-4)
• 4x complete ring sets
• 4x wrist pins
• 4x wrist pin locks

Product Description

The CP Pistons SC70458-4 set offers a performance upgrade for K-Series Honda/Acura engines, tailored especially to vehicles such as the 2001-2006 Civic Type-R and the 2002-2006 RSX. With an 87.50 mm bore and a 9.7:1 compression ratio, this set provides a strong balance of responsiveness, strength, and reliability for both street and track applications. Each piston is forged for durability, includes deep valve reliefs for aggressive camshafts, and comes fully equipped with high performance rings and wrist pins/locks.

As with all high-performance parts, proper matching is essential: ensure piston-to-valve clearance, proper deck height, and that the cylinder block is accurately bored/honed to 87.50 mm. Also verify that the rods, block height, and head gasket thickness align to achieve desired compression ratio. This part is sold as a set of four and fits models through at least 2013 for the Odyssey and other K-Series engines - but 2025 unconfirmed for new production OEM K-Series engines.