DSS Racing FX Series Forged Flat Top Piston Set

Chrysler / Dodge / Jeep / Ram 6.1L SRT8

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

Overview:

The DSS Racing FX Series Forged Flat Top Piston Set is engineered specifically for the Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 models equipped with the Gen III Hemi engine. Designed to deliver superior strength and reliability, these pistons are ideal for enthusiasts and professional builders seeking to enhance engine durability and performance. Whether you are upgrading your 6.1L Hemi for street, strip, or track use, this piston set offers a precision fit and optimized combustion characteristics to maximize power output and efficiency.

Crafted to exacting standards, the FX Series pistons feature a flat top design with a -1.5cc dish volume, providing a versatile compression ratio suitable for a variety of performance builds. Their compatibility with the 375 Small Block Mopar Hemi Gen III ensures seamless integration with existing engine components, making them a trusted choice for high-performance applications.

Key Features:

These forged pistons incorporate advanced design elements and materials to meet the demands of high-performance 6.1L Hemi engines:

• Precision forged construction for enhanced strength and durability
• Flat top piston design with -1.5cc dish for optimized combustion
• Comp height of 1.21 inches for proper deck clearance
• .927-inch wrist pin diameter with options for full-floating or press-fit configurations
• Ring groove dimensions of 1.2mm/1.2mm/3mm to accommodate high-performance piston rings
• Compatible with a 3.578-inch stroke and 6.243-inch connecting rods
• Available in multiple compression ratios: 65cc (11.17:1), 74cc (10.08:1), and 85cc (9.04:1)
• Designed for use in 375 Small Block Mopar Gen III Hemi engines

Construction & Design:

The DSS Racing FX Series pistons are forged from high-grade aluminum alloy, delivering an excellent balance of lightweight performance and structural integrity. The forging process refines the grain structure of the metal, resulting in pistons that resist cracking and deformation under extreme combustion pressures and temperatures. The flat top design promotes efficient combustion chamber dynamics, contributing to improved throttle response and power delivery.

Each piston is machined to tight tolerances to ensure consistent fitment and performance. The wrist pin bore is engineered to accept either full-floating or press-fit pins, allowing builders to tailor the assembly to their specific application. The ring grooves are precision cut to accommodate performance ring sets, ensuring optimal sealing and reduced blow-by.

Installation & Fitment:

These pistons are designed as direct replacements for most Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 Gen III Hemi engines. Installation requires standard engine assembly procedures, and no major modifications are typically necessary when paired with compatible rods and crankshafts. Builders should verify piston-to-deck clearance and ring end gaps during assembly to ensure optimal performance and reliability.

Whether you are performing a fresh build or upgrading an existing engine, the DSS Racing FX Series pistons provide a reliable foundation for high-performance applications.

What's Included:

• Set of forged flat top pistons (quantity as required for engine)
• Wrist pin options (full-floating or press-fit depending on SKU)
• Detailed specifications for compression ratio and piston dimensions

Ideal For:

This piston set is ideal for performance enthusiasts, engine builders, and racers who demand durable, high-quality components for their 6.1L Gen III Hemi engines. It suits street performance upgrades, drag racing, road racing, and other motorsport applications where strength and precision are critical. The multiple compression ratio options allow customization to match fuel types and tuning preferences.

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.