DSS Racing FX Series Forged Piston Set

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

1-6820-4085 / 2-6820-4085 / 3-6820-4085 / K1-6820-4085 / K2-6820-4085 / K3-6820-4085

Overview:

The DSS Racing Gen III Hemi FX Series Forged Piston Set is engineered specifically for the 6.1L SRT8 engines found in Chrysler, Dodge, Jeep, and Ram vehicles. Designed to replace factory pistons with a high-performance upgrade, these forged pistons offer enhanced strength, durability, and reliability under demanding conditions. Ideal for enthusiasts and racers looking to maximize engine efficiency and longevity, this piston set supports aggressive tuning and high RPM operation while maintaining excellent combustion characteristics.

With a 4.085" bore size and a compact design, these pistons fit most 6.1L SRT8 applications, providing a direct replacement that improves upon stock components. Whether you are rebuilding your engine or upgrading for performance gains, DSS Racing’s FX Series pistons deliver consistent quality and precision engineering.

Key Features:

These pistons incorporate advanced design elements and materials to meet the rigorous demands of high-performance Mopar engines:

• Forged construction for superior strength and resistance to cracking
• Flat top design with a -1.5cc dish for optimized combustion chamber volume
• Compact height of 1.21" for compatibility with Gen III Hemi 6.1L engines
• Ring groove dimensions of 1.2mm / 1.2mm / 3mm to accommodate high-performance piston rings
• Pin diameter of .984" with options for full-floating or press-fit configurations
• Stroke compatibility of 3.578" and connecting rod length of 6.243" for precise engine geometry
• Available compression ratios approximately ranging from 9.04 to 11.17 depending on combustion chamber volume (65cc, 74cc, 85cc)
• Designed specifically for the 375 Small Block Mopar Hemi Gen III platform

Construction & Design:

DSS Racing FX Series pistons are crafted from high-grade forged aluminum alloy, providing an excellent balance of lightweight properties and exceptional strength. The forging process refines the grain structure of the metal, resulting in pistons that withstand extreme thermal and mechanical stresses common in high-performance and racing environments.

The pistons feature a flat top design with a slight dish volume to optimize the compression ratio and combustion efficiency. Precision machining ensures tight tolerances for bore fitment and ring groove dimensions, contributing to reduced friction and improved sealing. The option for full-floating or press-fit wrist pins allows customization based on engine build preferences and durability requirements.

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 Hemi platform. Installation requires standard engine rebuild procedures, including proper honing of cylinder bores and ring installation. Depending on the wrist pin choice, either full-floating or press-fit installation techniques should be followed to ensure optimal performance and longevity.

Due to the precise dimensions and compatibility with stock components, these pistons typically require no additional modifications, making them an excellent upgrade for both rebuilds and performance enhancements.

What's Included:

• Set of forged pistons sized for 4.085" bore
• Wrist pins (.984") with options for full-floating or press-fit
• Piston rings compatible with 1.2/1.2/3mm groove sizes (rings may be sold separately)
• Installation instructions and technical specifications

Ideal For:

This piston set is ideal for performance enthusiasts, engine builders, and racers who demand reliable, high-strength components for their 6.1L SRT8 Mopar engines. Whether building a street performance engine, a track-focused race motor, or a durable daily driver with increased power output, these forged pistons provide the durability and precision needed to handle elevated boost, higher RPMs, and aggressive tuning.

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.