DSS Racing FX Series Forged Piston Set

Chrysler / Dodge / Jeep / Ram 6.4L 392 Models

1-6845-4055C / 2-6845-4055C / 3-6845-4055C / K1-6845-4055C / K2-6845-4055C / K3-6845-4055C

Overview:

The DSS Racing FX Series Forged Piston Set is engineered specifically for the Chrysler, Dodge, Jeep, and Ram 6.4L 392 HEMI engines. Designed to replace factory pistons with a high-performance upgrade, these forged pistons offer enhanced strength and durability for enthusiasts seeking reliable power gains and improved engine longevity. Ideal for street performance, mild racing, and high-output builds, this piston set ensures consistent performance under demanding conditions.

Each piston is crafted to exacting specifications to fit the 4.055" bore size of the 6.4L 392 Small Block Mopar HEMI Gen III engines. With a compression height of 1.21 inches and a -18cc dish top design, these pistons help optimize combustion chamber volume and compression ratios for balanced power and efficiency.

Key Features:

Built for performance and reliability, the DSS Racing FX Series Forged Pistons include the following key features:

• Compatible with Chrysler, Dodge, Jeep, and Ram 6.4L 392 HEMI engines
• 4.055" bore size tailored for Small Block Mopar HEMI Gen III applications
• Forged construction for superior strength and resistance to detonation
• 18cc dish top design to optimize combustion chamber volume
• Compression height of 1.21 inches for precise piston-to-deck clearance
• .927" wrist pin diameter with options for full-floating or press-fit pins
• Ring groove dimensions: 1.2mm top and second rings, 3mm oil ring
• Designed for 3.720" stroke and 6.2" connecting rods
• Available in multiple dish volumes to accommodate different compression ratios (65cc, 74cc, 85cc)

Construction & Design:

The FX Series pistons are forged from high-grade aluminum alloy, providing an optimal balance of lightweight design and exceptional strength. The forging process enhances grain structure, resulting in pistons that withstand high cylinder pressures and temperatures typical of performance engines. The -18cc dish top design reduces compression to prevent detonation while maintaining efficient combustion.

Each piston features precision-machined ring grooves and a durable skirt coating to minimize friction and wear. The wrist pin bore is engineered to accept either full-floating or press-fit pins, allowing flexibility depending on engine build preferences. These pistons are engineered to exact OEM dimensions to ensure a seamless fit and reliable operation.

Installation & Fitment:

This piston set is designed as a direct fit for most Chrysler, Dodge, Jeep, and Ram 6.4L 392 HEMI engines with a 4.055" bore. Installation requires standard engine rebuild procedures, including honing the cylinder walls and verifying clearances. The pistons accommodate a 3.720" stroke crankshaft and 6.2" connecting rods, matching factory specifications for smooth assembly.

Builders should select the appropriate dish volume piston to achieve the desired compression ratio based on their specific engine setup and fuel requirements. Proper ring installation and pin selection (full-floating or press-fit) are critical for optimal performance and durability.

What's Included:

• Set of forged aluminum pistons (quantity as per SKU selection)
• Wrist pins compatible with full-floating or press-fit configurations
• Precision-machined piston rings (1.2mm top and second rings, 3mm oil ring)

Ideal For:

This piston set is ideal for automotive enthusiasts and professional engine builders upgrading or rebuilding 6.4L 392 HEMI engines. It suits applications ranging from high-performance street vehicles to mild racing builds where enhanced strength and reliability are essential. The FX Series pistons provide a solid foundation for increased power output while maintaining engine longevity under demanding conditions.

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.