DSS Racing FX Series Gen III Hemi Forged Piston Set

Fits Most Chrysler / Dodge / Jeep / Ram 6.1L SRT8 Models

1-6840-4085D / 2-6840-4085D / 3-6840-4085D / K1-6840-4085D / K2-6840-4085D / K3-6840-4085D

Overview:

The DSS Racing FX Series Gen III Hemi Forged Piston Set is engineered specifically for Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 engines. Designed to meet the demands of high-performance applications, these pistons offer exceptional strength and durability for enthusiasts looking to upgrade their small block Mopar Hemi engines. Whether you are building a street performance motor or a track-ready powerplant, this piston set provides reliable, precision-engineered components that enhance engine efficiency and longevity.

These forged pistons are tailored for the 375 Small Block Mopar Hemi Gen III platform, featuring a 4.085" bore size and a compact 1.21" compression height. Their flat-top design with a -1.5cc dish optimizes combustion chamber dynamics, supporting a range of compression ratios to suit various build goals.

Key Features:

Built to deliver superior performance and durability, the DSS Racing FX Series pistons include the following key features:

• Forged construction for enhanced strength and resistance to high-stress conditions
• 4.085" bore size compatible with most Chrysler / Dodge / Jeep / Ram 6.1L SRT8 engines
• Compact 1.21" compression height for optimal piston-to-cylinder fitment
• 1.5cc flat-top piston design to improve combustion efficiency
• .927" wrist pin diameter, available in full-floating or press-fit configurations
• Ring groove dimensions of 1.2mm / 1.2mm / 3mm for reliable ring sealing and durability
• Designed for a 3.578" stroke and 6.243" connecting rod length, matching factory specifications
• Supports approximate compression ratios ranging from 9.04:1 to 11.17:1 depending on combustion chamber volume

Construction & Design:

These pistons are forged from high-quality aluminum alloy, providing an excellent balance of lightweight construction and robust strength. The forging process enhances grain structure and mechanical properties, allowing the pistons to withstand the intense pressures and temperatures found in high-performance Hemi engines. The flat-top design with a slight dish (-1.5cc) is engineered to optimize combustion chamber shape and promote efficient fuel burn.

The pistons feature precision-machined ring grooves and wrist pin bores to ensure tight tolerances and reliable operation. The option for full-floating or press-fit wrist pins allows builders to tailor the assembly to their specific performance needs and engine setup.

Installation & Fitment:

This piston set is designed as a direct fit for most Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 engines utilizing the Gen III small block Mopar Hemi platform. Installation requires standard engine assembly procedures, and the pistons are compatible with factory connecting rods and crankshaft stroke dimensions. No major modifications are typically necessary, making these pistons an ideal upgrade for rebuilds or performance builds.

What's Included:

• Set of forged pistons (quantity as required for engine configuration)
• Wrist pins (full-floating or press-fit depending on selected option)
• Ring groove machining for standard piston rings

Ideal For:

This piston set is perfect for automotive enthusiasts, engine builders, and racers seeking a durable, high-performance piston upgrade for their 6.1L SRT8 Hemi engines. Whether upgrading for increased power, improved reliability, or engine rebuilds, these pistons provide a solid foundation for enhanced engine performance in street, strip, or track applications.

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.