DSS Racing FX Series Forged Piston Set

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

1-6847-4055C / 2-6847-4055C / 3-6847-4055C / K1-6847-4055C / K2-6847-4055C / K3-6847-4055C

Overview:

The DSS Racing FX Series Forged Piston Set is engineered specifically for the Chrysler, Dodge, Jeep, and Ram 6.4L 392 HEMI engines, delivering exceptional strength and durability for high-performance applications. Designed to fit most 6.4L 392 models, these pistons are ideal for enthusiasts and professional builders seeking reliable, precision components to handle increased power and demanding conditions.

Built to withstand the rigors of boosted, nitrous, or naturally aspirated setups, the FX Series pistons offer a perfect balance of lightweight construction and robust design. Their forged construction ensures superior resistance to heat and stress, making them a trusted upgrade for serious Mopar HEMI builds.

Key Features:

These pistons incorporate advanced design elements and manufacturing techniques to optimize engine performance and longevity:

• Compatible with 384 Small Block Mopar HEMI Gen III engines
• 4.055" bore size tailored for 6.4L 392 applications
• Compression height of 1.21" for precise piston-to-deck clearance
• +4cc dome top design to enhance combustion efficiency
• .927" wrist pin diameter with options for full-floating or press-fit configurations
• Ring groove dimensions: 1.2mm top and second rings, 3mm oil ring groove
• Stroke compatibility: 3.720" stroke engines
• Connecting rod length: 6.2" for optimal piston travel and rod ratio
• Available in multiple dome volumes to adjust compression ratio: 65cc (12.32:1), 74cc (11.02:1), and 85cc (9.79:1)

Construction & Design:

The FX Series pistons are forged from premium-grade aluminum alloy, providing a lightweight yet incredibly strong foundation to endure high cylinder pressures and temperatures. The forging process enhances grain structure and mechanical properties, resulting in pistons that resist cracking, scuffing, and deformation under extreme conditions.

Each piston features a precision-machined dome top with a +4cc volume to optimize combustion chamber shape and improve power output. The ring grooves are carefully cut to accommodate high-performance piston rings, ensuring excellent sealing and oil control. The wrist pin bore is engineered for either full-floating or press-fit installation, offering flexibility depending on engine build preferences.

Installation & Fitment:

Designed as a direct fit for most Chrysler, Dodge, Jeep, and Ram 6.4L 392 HEMI engines, these pistons require minimal modifications for installation. Builders should verify bore size compatibility and select the appropriate dome volume to match their desired compression ratio and fuel type. Proper ring end gap and piston-to-wall clearance should be checked during assembly to ensure optimal performance and longevity.

What's Included:

• Set of forged pistons (quantity as per engine requirements)
• Wrist pins compatible with full-floating or press-fit installation
• Detailed specifications for compression height, dome volume, and ring groove dimensions

Ideal For:

This piston set is perfect for performance enthusiasts, engine builders, and racers upgrading or rebuilding their 6.4L 392 HEMI engines. Whether building a naturally aspirated powerhouse or a forced induction monster, the DSS Racing FX Series pistons provide the durability and precision needed to maximize power and reliability in street, strip, or track 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.