JE Pistons 149139S Forged Dome Piston Bore Single - 2618 3.858

The JE Pistons 149139S is a single forged racing piston engineered for high-performance powersports applications. Featuring a dome top design, this piston is CNC-machined from premium 2618 low-silicon aluminum alloy — the material of choice for high-boost, high-heat, and high-RPM racing environments where strength and durability are non-negotiable.

Key Specifications:

• Bore Diameter: 3.858 in. (98.00 mm)
• Compression Distance (CD): 1.170 in.
• Wrist Pin Diameter: 0.945 in.
• Top Design: Dome
• Alloy: 2618 forged aluminum

Key Features:

• Forged from 2618 aluminum alloy for superior strength under extreme thermal and mechanical loads
• Fully CNC-machined to exacting tolerances for precise fit and optimal ring seal
• Dome top design engineered to optimize compression ratio in performance builds
• Designed, forged, and machined entirely in-house by JE Pistons for full quality control
• Compatible with Honda VTR 1000 high-performance engine builds

WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or reproductive harm. For more information, visit P65Warnings.ca.gov.

JE Pistons has been the industry leader in forged racing pistons since 1947, supplying top engine builders and race teams across NASCAR, NHRA, IRL, and more. The 149139S is sold as a single piston, making it ideal for replacement or matched-set custom builds.