Wiseco 4729P2 HD 1340 Shovelhead 7:1 CR Forged Piston Kit 3.517in Bore +0.020in Oversize

The Wiseco 4729P2 is a forged piston kit engineered specifically for the Harley-Davidson 80 cubic inch (1340cc) Shovelhead V-Twin engine. Designed for the 1978–1984 model years, this kit delivers a 7:1 compression ratio at a 3.517-inch (+0.020" oversize) bore, making it an ideal choice for low-compression rebuilds, sidecar applications, or engines with forced induction.

Key Features:

• Forged from high-silicon aluminum alloy for superior strength, durability, and heat resistance
• 3.517-inch bore diameter — +0.020" oversize over the 3.497" stock bore
• 7:1 compression ratio with positive dome piston design (+29.7cc dome volume)
• 4.250-inch stroke — engineered for the stock 1340cc Shovelhead architecture
• Optimized piston skirt geometry for reduced friction and maximum power output
• Machined valve pockets deeper and larger than stock to accommodate modified or high-lift cams
• Kit includes piston, rings, wrist pin, and circlips — everything needed for a complete top-end rebuild
• Oversize bore — cylinder boring and honing required for proper installation
• Manufactured in the USA by Wiseco

Installation Notes:

• Recommended piston-to-cylinder wall clearance: 0.003"–0.0035" (0.075mm–0.089mm)
• Minimum ring end gap: 0.004" per inch of bore size (approximately 0.014" for this application)
• Always verify valve-to-piston clearance when using modified cams
• Oversize pistons require cylinder boring and honing — cylinder sleeving is required for oversized applications

Wiseco has over 80 years of experience engineering performance pistons for powersports applications. Their V-Twin piston line is purpose-built for specific engine platforms, manufactured to tight tolerances for reliable performance in street and custom builds alike. Kit part number cross-references: piston 4729P2, bore size 3517X, ring set S535, wrist pin W5731, circlip W5916.