DSS Racing Gen III Hemi FX Series Forged Piston Set

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

1-6820-4055 / 2-6820-4055 / 3-6820-4055 / K1-6820-4055 / K2-6820-4055 / K3-6820-4055

Overview:

The DSS Racing Gen III Hemi FX Series Forged Piston Set is engineered specifically for the Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 engines. Designed to fit a 4.055" bore, these pistons are an ideal upgrade for enthusiasts seeking enhanced durability and performance in their 370 Small Block Mopar Hemi Gen III powerplants. Whether you are rebuilding your engine or upgrading for higher horsepower applications, these forged pistons offer superior strength and reliability compared to stock cast components.

Built to exacting standards, the FX Series pistons feature a compact 1.21" compression height and a -1.5cc flat top design, optimizing combustion efficiency and allowing for precise control over compression ratios. This piston set is perfect for high-performance street, track, or racing applications where durability and consistent performance are critical.

Key Features:

These pistons incorporate advanced engineering and materials to deliver outstanding performance and longevity. Key features include:

• Compatible with 4.055" bore size for most Chrysler / Dodge / Jeep / Ram 6.1L SRT8 engines
• Forged construction for superior strength and resistance to detonation
• Compact 1.21" compression height for optimized piston-to-cylinder geometry
• 1.5cc flat top piston design to fine-tune compression ratios
• .984" pin diameter with options for full-floating or press-fit pins
• Ring groove dimensions of 1.2mm / 1.2mm / 3mm for reliable ring sealing
• Designed for use with 3.578" stroke crankshafts and 6.243" connecting rods
• Approximate compression ratios available: 65cc chamber - 11.05:1, 74cc chamber - 9.98:1, 85cc chamber - 8.93:1
• Precision machining ensures consistent fit and performance

Construction & Design:

The DSS Racing FX Series pistons are crafted from high-grade forged aluminum alloy, providing an excellent balance of strength, weight, and thermal conductivity. Forging enhances the grain structure of the metal, resulting in pistons that withstand high cylinder pressures and temperatures without cracking or deforming. The flat top design with a slight dish (-1.5cc) allows for precise control over combustion chamber volume and compression ratio, which is critical for tuning performance and avoiding detonation.

Each piston features carefully engineered ring grooves to accommodate high-performance piston rings, ensuring optimal sealing and oil control. The pin bore is designed to accept either full-floating or press-fit wrist pins, giving builders flexibility depending on their engine setup and intended use.

Installation & Fitment:

This piston set is designed as a direct fit for most Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 engines with a 4.055" bore. Installation requires standard engine rebuild procedures, including proper honing and cleaning of the cylinder bores. The pistons are compatible with the factory stroke of 3.578" and connecting rod length of 6.243". Builders should verify clearances and ring end gaps during assembly to ensure optimal performance and longevity.

These pistons are suitable for both full-floating and press-fit wrist pin configurations, allowing for customization based on engine build preferences. No major modifications are typically required when upgrading from stock pistons, making this set an excellent choice for performance rebuilds and upgrades.

What's Included:

• Set of four DSS Racing Gen III Hemi FX Series forged pistons (4.055" bore)
• Wrist pin compatibility for full-floating or press-fit installation
• Precision-machined ring grooves for 1.2mm top and second rings, 3mm oil ring

Ideal For:

This piston set is ideal for automotive enthusiasts, engine builders, and racers who demand enhanced strength and reliability from their 6.1L SRT8 Hemi engines. Whether upgrading for increased horsepower, rebuilding a worn engine, or preparing a vehicle for track use, these forged pistons provide the durability and performance needed to handle aggressive driving and high cylinder pressures.

They are especially suited for applications requiring improved detonation resistance and precise compression ratio control, making them a smart choice for street performance, drag racing, and road course competition.

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.