DSS Racing FX Series Forged Piston Set

Chrysler / Dodge / Jeep / Ram 6.1L SRT8

1-6845-4125D / 2-6845-4125D / 3-6845-4125D / K1-6845-4125D / K2-6845-4125D / K3-6845-4125D

Overview:

The DSS Racing FX Series Forged Piston Set is engineered specifically for the Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 engines, delivering exceptional strength and durability for high-performance applications. Designed to fit a 4.125" bore, these pistons are ideal for enthusiasts and professional builders seeking reliable, precision-crafted components for their 383 Small Block Mopar Hemi Gen III builds.

With a compact dish top design and a compression height of 1.21 inches, these pistons optimize combustion efficiency while maintaining compatibility with factory and aftermarket components. Whether you are upgrading for increased power, durability, or engine longevity, the DSS Racing FX Series pistons provide a solid foundation for your performance build.

Key Features:

These forged pistons incorporate advanced design elements to meet the demands of high-output Mopar engines:

• Compatible with 4.125" bore size, tailored for 6.1L SRT8 engines
• Forged construction for superior strength and heat resistance
• Compact dish top with -18cc volume to optimize compression ratios
• Compression height of 1.21 inches for precise piston-to-deck clearance
• Pin diameter of .927" available in full-floating or press-fit options
• Ring groove dimensions: 1.2mm top and second rings, 3mm oil ring
• Designed for 3.578" stroke and 6.243" connecting rods
• Approximate compression ratios vary by combustion chamber volume: 9.55:1 (65cc), 8.78:1 (74cc), 8.02:1 (85cc)

Construction & Design:

The DSS Racing FX Series pistons are crafted from high-quality forged aluminum alloy, providing an optimal balance of lightweight strength and thermal conductivity. The forging process enhances grain structure and durability, allowing these pistons to withstand the rigors of high-performance and forced induction applications.

The pistons feature a carefully engineered dish top design with a -18cc volume to accommodate various combustion chamber sizes and compression ratios. Precision-machined ring grooves ensure proper sealing and reduced friction, while the choice of full-floating or press-fit wrist pins allows customization based on engine build preferences.

Installation & Fitment:

These pistons are designed as direct replacements for most Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 engines with a 4.125" bore. Installation requires standard engine assembly procedures, and compatibility with factory rods and crankshafts is maintained. Builders should verify clearances and ring end gaps during assembly to ensure optimal performance and reliability.

What's Included:

• Set of four DSS Racing FX Series forged pistons
• Wrist pins (.927") with options for full-floating or press-fit installation
• Precision-machined ring grooves ready for standard ring sets

Ideal For:

This piston set is ideal for performance enthusiasts, engine builders, and racers upgrading or rebuilding Chrysler, Dodge, Jeep, or Ram 6.1L SRT8 engines. Whether building a street performance engine, a track-ready machine, or a reliable high-output powerplant, these forged pistons offer the strength and design features necessary to support increased horsepower and torque demands.

DSS Racing — Founded in 1983 originally as Danny’s Speed Shop, DSS Racing has grown from a small Midwest performance engine shop into a respected name in forged engine components for the high-performance and racing markets. Based in St. Charles, Illinois, DSS is best known for its forged pistons and machined engine parts made in the USA that have been used in championship engines and thousands of builds, blending old-school racing roots with precision manufacturing for enthusiasts and racers alike.