Wiseco 4725P1 Forged Piston .010 Over 1340cc Evo Big Twin 10:1 Compression

The Wiseco 4725P1 is a forged replacement piston designed for the 80ci (1340cc) Harley-Davidson Evolution Big Twin engine. This is a .010 over (3.508" bore) piston with a 10:1 compression ratio and a domed design, producing a displacement of 1345cc. The companion ring set is Wiseco part number 3507X.

Wiseco pistons are forged from high-silicon, low-expansion aluminum alloy, delivering superior strength, reduced weight, improved heat transfer, and extended service life compared to cast alternatives. The unique piston profile allows for tight piston-to-wall clearances, contributing to quieter operation and improved ring seal.

Key Features:

• Forged high-silicon aluminum construction for maximum strength and durability
• .010 oversize bore — 3.508" finished bore diameter
• 10:1 compression ratio — domed piston design
• 1345cc displacement with 4.250" stroke
• CNC diamond-turned finish ensures precise sizing with no variation
• Compatible with cast iron, chrome, nikasil, and boron composite cylinder bores
• Enlarged valve pockets accommodate larger valves and high-lift camshafts
• Ring land grooves reduce detonation and improve top ring sealing
• Wrist pin bores are ream-fit for precise geometric tolerances
• Companion ring set: Wiseco 3507X

Dome specifications: Interior valve pocket depth -0.143" (diameter 2.080"); Exterior valve pocket depth -0.138" (diameter 1.740"). This piston is sold individually. Oversize pistons may require cylinder boring or sleeving — consult a qualified machine shop prior to installation.