Wiseco 6557M86 Pro Tru Sport Compact Forged Piston 86mm Bore

The Wiseco 6557M86 is a Pro Tru Sport Compact Series forged replacement piston with an 86mm bore diameter, engineered for performance-minded builders who demand strength and precision without sacrificing value. Manufactured in Mentor, Ohio, this piston is part of Wiseco's industry-trusted Pro Tru lineup — the go-to choice for sport compact engine builds.

Key Features:

• Forged 4032 aluminum construction — dedicated forgings specific to the final piston shape deliver superior strength and reduced weight compared to cast alternatives
• 86mm bore diameter — precision-machined on state-of-the-art CNC equipment for tight tolerances and consistent fit
• Plasma moly ring package included — pre-gapped 1/16", 1/16", 3/16" ring set provides excellent combustion seal, reduced friction, and extended service life
• Pins and clips included — complete piston assembly kit for a straightforward engine rebuild
• ArmorGlide skirt coating — Wiseco's proprietary skirt treatment reduces friction, minimizes piston rock, and allows tighter piston-to-wall clearances
• Available in multiple compression volumes — allows the engine builder to dial in the exact compression ratio required for their specific application
• Recommended ring set: 8600XX (sold separately if needed)
• American-made by skilled Ohio craftsmen using advanced forging presses and CNC machinery

The Pro Tru Sport Compact Series represents Wiseco's commitment to delivering race-proven forged piston technology at an attainable price point. Whether building a street-driven sport compact or a dedicated track car, the 6557M86 provides the reliability and performance characteristics that Wiseco has been known for since 1941.