DSS Racing Gen III Hemi FX Series Forged Piston Set

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

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

Overview:

The DSS Racing Gen III Hemi FX Series Forged Piston Set is engineered specifically for the Chrysler, Dodge, Jeep, and Ram 6.4L 392 engines. Designed to meet the demands of high-performance applications, these pistons provide enhanced strength, durability, and reliability for enthusiasts and professional builders alike. Whether you are upgrading your engine for street performance, racing, or heavy-duty use, this piston set offers a precision fit and superior construction to maximize your engine’s potential.

These pistons are forged to exacting standards, ensuring consistent quality and performance. They are ideal for those seeking to improve engine efficiency, withstand higher cylinder pressures, and maintain optimal compression ratios without sacrificing reliability.

Key Features:

Built for performance and durability, the DSS Racing Gen III Hemi FX Series pistons include the following key features:

• Compatible with 4.085" bore size, fitting most Chrysler / Dodge / Jeep / Ram 6.4L 392 engines
• Forged construction for superior strength and resistance to wear
• Comp height of 1.21" with a -1.5cc flat top design for optimized combustion
• .927" wrist pin diameter available in full-floating or press-fit options
• Precision ring grooves sized at 1.2mm / 1.2mm / 3mm for reliable ring sealing
• Designed for a 3.720" stroke and 6.2" connecting rods, matching factory specifications
• Available in multiple combustion chamber volumes (65cc, 74cc, 85cc) to tailor compression ratios
• Approximate compression ratios ranging from 9.36:1 to 11.57:1 depending on chamber volume

Construction & Design:

The DSS Racing FX Series pistons are crafted from high-grade forged aluminum alloy, delivering an optimal balance of lightweight design and exceptional strength. The forging process enhances the grain structure of the metal, resulting in pistons that can endure the extreme pressures and temperatures found in high-performance Hemi engines.

The flat-top piston design with a slight dish (-1.5cc) promotes efficient combustion and helps control detonation under boost or high compression conditions. The pistons feature precision-machined ring grooves and wrist pin bores to ensure tight tolerances and long-lasting performance. Options for full-floating or press-fit wrist pins allow builders to customize installation based on their specific engine setup and performance goals.

Installation & Fitment:

This piston set is designed to fit most Chrysler, Dodge, Jeep, and Ram 6.4L 392 Hemi engines with a 4.085" bore. Installation requires standard engine rebuilding procedures and may necessitate professional machining to ensure proper clearances and fitment. The pistons are compatible with factory stroke and rod lengths, making them a direct replacement or upgrade for stock components.

Builders should verify compatibility with their specific engine block and consider ring package and wrist pin options during assembly. Proper installation and break-in procedures are essential to maximize piston life and engine performance.

What's Included:

• Set of forged pistons (quantity as per kit selection)
• Wrist pins (full-floating or press-fit depending on option)
• Precision-machined piston rings (1.2mm top and second rings, 3mm oil ring)
• Installation instructions and technical specifications

Ideal For:

The DSS Racing Gen III Hemi FX Series Forged Piston Set is ideal for performance enthusiasts, engine builders, and racers who demand reliable, high-strength components for their 6.4L 392 Hemi engines. Whether upgrading for increased horsepower, forced induction setups, or extended durability under track conditions, these pistons provide a solid foundation for a high-performance build.

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.