Wiseco SK1146 Pro-Lite Snowmobile Top End Piston Kit 64.5mm Bore +0.5mm Oversize

The Wiseco SK1146 is a Pro-Lite forged top end piston kit precision-matched and balanced for the Polaris 580 Indy XLT and XLT Special (1993–1994) with liquid-cooled, cast iron bore engines. Bored to 64.5mm (+0.50mm oversize), this kit is engineered for riders who demand durability and performance beyond what stock cast pistons can deliver.

Key Features:

• Pro-Lite forged construction — CNC-machined from high-silicon aerospace-grade alloy bar stock for a superior strength-to-weight ratio
• 64.5mm bore diameter — 0.50mm oversize for worn or re-bored cylinders
• Optimized cam shape and profile — CNC-machined for peak horsepower output and extended service life
• Forged grain structure — aligned to part geometry for higher mechanical properties, improved impact resistance, and fatigue strength versus cast alternatives
• Skirt coating — reduces friction and wear during break-in and high-performance operation
• Complete kit — includes forged piston, high-performance rings, alloy wrist pin, and circlips
• USA manufactured — forged and machined entirely in-house at Wiseco's domestic facility

Unlike brittle cast pistons that can fail catastrophically when material yield strength is exceeded, Wiseco's forged Pro-Lite pistons feature a condensed, aligned grain structure that resists impact and fatigue under the extreme thermal and mechanical loads of snowmobile racing. Wiseco's vertically integrated manufacturing process — from raw bar stock through skirt coating — ensures consistent quality and precise tolerances in every kit.

The SK1146 is a direct fit for cast iron bore applications and is developed from race-proven designs trusted by top snocross and cross-country competition teams. Please note: Wiseco pistons require Wiseco rings only — ring types are not interchangeable.