DSS Racing FX Series Forged Piston Set

Fits Most Chrysler / Dodge / Jeep / Ram 6.4L 392 Models

1-6845-4090C / 2-6845-4090C / 3-6845-4090C / K1-6845-4090C / K2-6845-4090C / K3-6845-4090C

Overview:

The DSS Racing FX Series Forged Piston Set is engineered specifically for high-performance applications in Chrysler, Dodge, Jeep, and Ram vehicles equipped with the 6.4L 392 HEMI engine. Designed to fit most 6.4L 392 models, these pistons offer a perfect balance of strength, durability, and precision fitment for enthusiasts and builders looking to upgrade their engine’s bottom end. Whether you are building a street performance engine or a race-ready powerplant, these forged pistons provide the reliability and performance needed to handle increased power and boost levels.

With a bore size of 4.090 inches and a compatible stroke of 3.720 inches, this piston set is tailored for the 391 Small Block Mopar HEMI Gen III platform. The pistons feature a compact dish top design with an 18cc dish volume, helping to optimize combustion chamber dynamics and compression ratios for improved power delivery and efficiency.

Key Features:

These DSS Racing forged pistons incorporate advanced design elements and manufacturing techniques to ensure superior performance and longevity:

• Forged construction for enhanced strength and durability under high-stress conditions
• FX Series design optimized for 6.4L 392 HEMI engines, ensuring precise fit and function
• 1.21" compression height for compatibility with stock and aftermarket rods
• 18cc dish top piston crown to control compression ratio and improve combustion
• .927" wrist pin diameter with options for full-floating or press-fit pins
• Ring groove dimensions of 1.2mm top and second rings, 3mm oil ring for effective sealing
• Compatible with 6.2" connecting rods and 3.720" stroke crankshafts
• Available in multiple dish volumes (65cc, 74cc, 85cc) to tailor compression ratios from 9.74:1 down to 8.18:1

Construction & Design:

DSS Racing utilizes premium forged aluminum alloys to manufacture the FX Series pistons, delivering a combination of lightweight strength and thermal resistance. The forging process enhances grain structure and mechanical properties, allowing these pistons to withstand the rigors of high RPM and elevated cylinder pressures common in performance and racing engines.

The pistons are precision-machined to exacting tolerances, ensuring optimal ring sealing and minimal friction. The dish top design reduces detonation risk by controlling compression, while the ring grooves are engineered to maintain ring stability and oil control under demanding conditions. The wrist pin options provide flexibility for builders preferring either full-floating or press-fit configurations based on their engine setup.

Installation & Fitment:

This piston set is designed for direct fitment in most Chrysler, Dodge, Jeep, and Ram 6.4L 392 HEMI engines, making it an ideal upgrade for rebuilds or performance builds. Installation requires standard engine assembly procedures, and compatibility with stock or aftermarket connecting rods and crankshafts is ensured by the specified dimensions. Builders should verify clearances and ring end gaps during installation to achieve optimal performance and reliability.

What's Included:

• Set of forged pistons sized for 4.090" bore
• Wrist pins (.927") with options for full-floating or press-fit installation
• Precision-machined ring grooves for 1.2mm top and second rings, 3mm oil ring
• Multiple dish volume options to customize compression ratio

Ideal For:

The DSS Racing FX Series Forged Piston Set is perfect for engine builders, performance enthusiasts, and racers upgrading or rebuilding their 6.4L 392 HEMI engines. Whether you are aiming for increased horsepower, improved durability, or enhanced engine response, these pistons provide a reliable foundation for high-performance builds in street, strip, or off-road 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.