DSS Racing FX Series Forged Piston Set

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

1-6840-4055D / 2-6840-4055D / 3-6840-4055D / K1-6840-4055D / K2-6840-4055D / K3-6840-4055D

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, this set offers enhanced strength and durability for high-performance applications. Whether you are rebuilding your engine or upgrading for increased power and reliability, these pistons provide a solid foundation for improved combustion efficiency and engine longevity.

Ideal for enthusiasts and professional builders alike, these pistons are crafted to withstand the rigors of aggressive driving and forced induction setups. Their precise dimensions and compatibility with the Gen III Hemi architecture ensure a seamless fit and optimal performance.

Key Features:

Built with advanced engineering and attention to detail, the DSS Racing FX Series pistons deliver a range of benefits:

• Forged construction for superior strength and resistance to high stress
• Designed for a 4.055" bore, fitting most Chrysler/Dodge/Jeep/Ram 6.1L SRT8 engines
• Comp height of 1.21" with a -1.5cc flat top design for efficient combustion
• .927" wrist pin diameter with options for full-floating or press-fit pins
• Ring groove dimensions of 1.2mm/1.2mm/3mm for reliable sealing and reduced friction
• Compatible with a 3.578" stroke and 6.243" connecting rods
• Available in multiple combustion chamber volumes to tailor compression ratios (65cc, 74cc, 85cc)
• Optimized for an approximate compression ratio range from 8.93:1 to 11.05:1 depending on chamber volume

Construction & Design:

Each piston in the DSS Racing FX Series is forged from high-grade aluminum alloy, delivering a perfect balance of lightweight design and exceptional durability. The forging process enhances grain structure, providing superior fatigue resistance and strength compared to cast pistons. The flat top design with a slight dish (-1.5cc) improves combustion efficiency and helps control detonation under high load conditions.

The pistons feature precision-machined ring grooves and wrist pin bores to ensure tight tolerances and reliable sealing. The option for full-floating or press-fit wrist pins allows customization based on engine build preferences. This attention to detail in design and manufacturing ensures consistent performance and longevity in demanding environments.

Installation & Fitment:

These pistons are designed as direct replacements for most Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 Gen III Hemi engines with a 4.055" bore. Installation requires standard engine rebuild procedures and proper ring end gap setting. No major modifications are typically necessary, but professional installation is recommended to ensure optimal fitment and performance. Compatibility with stock or aftermarket connecting rods and crankshafts is maintained, provided the specified stroke and rod length are used.

What's Included:

• Set of forged pistons (quantity as per engine requirements)
• Wrist pins (full-floating or press-fit options depending on SKU)
• Ring grooves machined and ready for piston rings (rings not included)
• Detailed specifications and installation guidelines

Ideal For:

This piston set is perfect for performance enthusiasts, engine builders, and racers looking to upgrade or rebuild their 6.1L SRT8 engines with components that offer enhanced strength and reliability. It suits naturally aspirated builds as well as forced induction applications where durability and precise combustion chamber control are critical. Whether upgrading for street performance, track use, or off-road applications, these pistons provide a dependable foundation for increased power and engine longevity.

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.