DSS Racing Gen III Hemi FX Series Forged Piston Set

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

1-6840-4075C / 2-6840-4075C / 3-6840-4075C / K1-6840-4075C / K2-6840-4075C / K3-6840-4075C

Overview:

The DSS Racing Gen III Hemi FX Series Forged Piston Set is engineered specifically for the 6.4L 392 engines found in Chrysler, Dodge, Jeep, and Ram vehicles. Designed to meet the demands of high-performance builds, these pistons offer exceptional strength and durability for enthusiasts and professional builders alike. Whether upgrading for increased power or replacing worn factory components, this piston set delivers reliable performance and precision fitment.

These pistons are crafted to optimize combustion efficiency and withstand the rigors of boosted or naturally aspirated applications. Their forged construction ensures superior resistance to heat and stress, making them ideal for street, track, or racing use.

Key Features:

Built with advanced engineering and quality materials, the DSS Racing FX Series pistons provide numerous benefits:

• Compatible with 4.075" bore size for most Chrysler / Dodge / Jeep / Ram 6.4L 392 engines
• Forged construction for enhanced strength and durability under high stress
• Flat top design with -1.5cc dish for optimized combustion chamber volume
• Comp height of 1.21" for precise piston-to-deck clearance
• .927" wrist pin diameter, available in full-floating or press-fit options
• Ring groove dimensions: 1.2mm top and second rings, 3mm oil ring for effective sealing
• Compatible with 3.720" stroke and 6.2" connecting rods
• Available in multiple compression ratios to suit different build goals: approximately 11.52:1 (65cc), 10.4:1 (74cc), and 9.32:1 (85cc)

Construction & Design:

The DSS Racing FX Series pistons are forged from premium-grade aluminum alloy, providing an excellent balance of lightweight design and structural integrity. The forging process enhances grain structure, resulting in pistons that resist cracking, scuffing, and thermal fatigue. The flat top with a slight dish (-1.5cc) is engineered to optimize combustion efficiency and reduce detonation risk.

Each piston features precision-machined ring grooves and a wrist pin bore designed for either full-floating or press-fit pins, allowing builders to tailor the setup to their specific application. The pistons are designed to maintain tight tolerances for consistent performance and longevity in demanding environments.

Installation & Fitment:

This piston set is designed for direct fitment in most Chrysler, Dodge, Jeep, and Ram 6.4L 392 Hemi engines with a 4.075" bore. Installation requires standard engine assembly procedures, and the pistons are compatible with factory or aftermarket components matching the specified dimensions. Builders should verify compression ratio and clearance specifications to ensure optimal performance and reliability.

What's Included:

• Set of forged pistons sized for 4.075" bore
• Wrist pins (.927") with options for full-floating or press-fit installation
• Precision-machined ring grooves compatible with 1.2/1.2/3mm ring sets

Ideal For:

This piston set is ideal for performance enthusiasts, engine builders, and racers upgrading or rebuilding Chrysler, Dodge, Jeep, or Ram 6.4L 392 engines. It suits naturally aspirated and forced induction applications where enhanced durability, improved combustion, and reliable power delivery are priorities. Whether building a street performance engine or a track-ready race motor, these pistons offer a solid foundation for high-output builds.

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.