Wossner RSX Type-S & Civic Type-R K20 9.5:1 Compression Forged Piston Kit Hard Anodised

Wossner RSX Type-S & Civic Type-R K20 9.5:1 Compression Forged Piston Kit Hard Anodised

The Wossner K20 Hard Anodised Forged Piston Kit is the ultimate internal solution for high-output Honda builds pushing the boundaries of forced induction. Specifically engineered for the K20A2, K20Z1, and K20Z4 engines, this "Premium Plus" series kit drops the compression to 9.5:1, creating a perfect balance between off-boost response and high-boost safety. The standout feature is the professional Hard Anodised crown coating, which acts as a sophisticated thermal barrier, protecting the piston from the extreme cylinder temperatures and pressures generated by large turbochargers.

Manufactured in Germany from high-silicon 4032-T6 forged aluminium, these pistons offer incredible structural integrity with minimal thermal expansion. The Hard Anodising process significantly increases surface hardness and prevents "micro-welding"—a common failure where the piston ring fuses to the groove under extreme thermal stress. Combined with Wossner’s signature Moly skirt coating for reduced friction and a mirror-polished finish, this kit ensures your K20 remains reliable and quiet, whether on a daily-driven street car or a dedicated time-attack machine.

Key Performance Features

• Turbo-Ready 9.5:1 Compression: Optimised for forced induction, allowing for higher boost pressures and more aggressive ignition timing.

• Hard Anodised Crown Coating: Provides a ceramic-like shield against heat erosion and surface melting during high-load operation.

• Anti-Micro-Welding Protection: The anodised ring lands ensure the rings remain free and seal perfectly, even under extreme thermal stress.

• 4032-T6 High-Silicon Alloy: Offers superior strength with low expansion rates, allowing for tighter clearances and quieter engine operation.

• Complete Professional Kit: Includes four forged pistons, high-performance ring sets, 22mm gudgeon pins, and heavy-duty circlips.

Technical Specifications

Why Choose Wossner?

Wossner is globally recognised as a pioneer in high-performance engine internals, with a heritage rooted in European motorsport and precision engineering. By owning and operating their own forging plant in Germany, Wossner maintains absolute control over the quality and consistency of their aluminium alloys. This vertical integration allows them to produce pistons that are lighter, stronger, and more thermally efficient than standard cast or mass-produced forged components. When you choose Wossner for your K20 build, you are installing a product trusted by world-class engine builders to deliver podium-winning performance and daily-driver reliability.