DSS Racing FX Series +4cc Dome Top Forged Piston Set

Fits Most Chrysler / Dodge / Jeep / Ram 6.1L SRT8 Gen III Mopar Hemi

1-6847-4125D / 2-6847-4125D / 3-6847-4125D / K1-6847-4125D / K2-6847-4125D / K3-6847-4125D

Overview:

The DSS Racing FX Series +4cc Dome Top Forged Piston Set is engineered specifically for the 6.1L Gen III Mopar Hemi engine, commonly found in Chrysler, Dodge, Jeep, and Ram SRT8 models. Designed to enhance engine performance and durability, these pistons offer a precise combination of lightweight construction and strength to handle high-stress conditions. Ideal for enthusiasts and professional builders seeking reliable, high-quality components for street or track applications.

With a +4cc dome top design, these pistons increase compression ratios, delivering improved combustion efficiency and power potential. They are compatible with both full-floating and press-fit wrist pins, providing flexibility for various engine builds.

Key Features:

These forged pistons incorporate advanced design elements to optimize performance and reliability:

• +4cc dome top for increased compression and power output
• Forged construction for superior strength and durability under high load
• Comp height of 1.21" to maintain proper piston-to-head clearance
• Pin diameter of .927" compatible with full-floating or press-fit wrist pins
• Ring groove dimensions: 1.2mm top and second rings, 3mm oil ring for effective sealing
• Designed for 3.578" stroke and 6.243" connecting rods typical of 6.1L Gen III Hemi engines
• Available in multiple combustion chamber volumes (65cc, 74cc, 85cc) to tailor compression ratios from approximately 9.74:1 to 12.24:1
• Precision machining ensures consistent fitment and performance

Construction & Design:

Manufactured from high-grade forged aluminum alloy, these pistons deliver an optimal balance of lightweight design and exceptional strength. The forging process refines the metal grain structure, enhancing fatigue resistance and thermal conductivity. The dome top shape is engineered to improve combustion chamber dynamics, promoting efficient flame propagation and power delivery.

Each piston features carefully machined ring grooves and pin bores to ensure tight tolerances and reliable sealing. The option for full-floating or press-fit wrist pins allows builders to customize assembly based on application requirements and performance goals.

Installation & Fitment:

These pistons are designed as direct replacements for the 6.1L Gen III Mopar Hemi engines found in many Chrysler, Dodge, Jeep, and Ram SRT8 vehicles. Installation requires standard engine assembly procedures, with attention to proper ring end gap and piston orientation. No major modifications are typically necessary, making them suitable for both rebuilds and performance upgrades.

Consult your engine builder or service manual for specific torque specs and clearances to ensure optimal performance and longevity.

What's Included:

• Set of forged +4cc dome top pistons (quantity as required for engine configuration)
• Compatible wrist pins (full-floating or press-fit options depending on SKU)
• Precision-machined piston rings matching groove specifications
• Installation instructions and technical support documentation

Ideal For:

This piston set is ideal for performance enthusiasts, engine builders, and racers who demand increased compression and durability from their 6.1L Gen III Mopar Hemi engines. Whether upgrading a street car for spirited driving or building a track-focused machine, these pistons provide a solid foundation for enhanced power and reliability.

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.