DSS Racing FX Series Forged Pistons

Fits Most Chrysler / Dodge / Jeep / Ram 6.1L SRT8 Models

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

Overview:

The DSS Racing FX Series +4cc Dome Top Forged Pistons are precision-engineered performance components designed specifically for the Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 engines. These pistons are built to enhance engine durability and efficiency while supporting higher compression ratios for improved power output. Ideal for enthusiasts and professional builders looking to upgrade their 370 Small Block Mopar Hemi Gen III engines, these pistons provide a reliable foundation for high-performance builds and track-ready applications.

With a bore size of 4.055 inches and a +4cc dome top design, these pistons optimize combustion chamber volume to help achieve the desired compression ratios ranging from approximately 9.47:1 to 11.91:1, depending on the combustion chamber size. Their comp height of 1.21 inches and compatibility with full-floating or press-fit wrist pins make them versatile for various engine configurations.

Key Features:

Engineered for performance and durability, the DSS Racing FX Series pistons offer the following key features:

• Forged construction for superior strength and resistance to high stress and heat
• +4cc dome top design to increase compression and improve combustion efficiency
• Compatible with 4.055" bore size engines, tailored for 6.1L SRT8 applications
• Pin diameter of .927" available in full-floating or press-fit options for secure wrist pin retention
• Ring groove dimensions of 1.2mm/1.2mm/3mm to accommodate high-performance piston rings
• Stroke compatibility of 3.578" and connecting rod length of 6.243" for precise engine geometry
• Designed for 370 Small Block Mopar Hemi Gen III engines with a comp height of 1.21"
• Available in multiple combustion chamber volume options (65cc, 74cc, 85cc) to tailor compression ratios

Construction & Design:

These pistons are crafted from high-grade forged aluminum alloy, ensuring exceptional strength-to-weight ratio and durability under extreme operating conditions. The forging process enhances the metal grain structure, providing superior resistance to cracking and deformation compared to cast pistons. The dome top design is precisely machined to optimize combustion chamber shape and volume, improving thermal efficiency and power delivery.

The pistons feature carefully engineered ring grooves and pin bosses to maintain ring seal and wrist pin stability during high RPM operation. The option for full-floating or press-fit wrist pins allows builders to select the best fitment for their engine setup, balancing ease of assembly with performance requirements.

Installation & Fitment:

These DSS Racing FX Series pistons are designed as direct replacements for most Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 engines, making installation straightforward for experienced engine builders. Minimal modifications are typically required when upgrading from stock pistons, provided the engine bore size matches the 4.055" specification. Proper ring end gap and piston-to-wall clearance should be verified during installation to ensure optimal performance and longevity.

What's Included:

• Set of forged +4cc dome top pistons (quantity as per selected SKU)
• Wrist pins (full-floating or press-fit depending on selection)
• Piston rings compatible with 1.2/1.2/3mm groove dimensions (may vary by package)

Ideal For:

These pistons are ideal for performance enthusiasts, professional engine builders, and racers seeking to upgrade their 6.1L SRT8 engines for increased compression, improved durability, and enhanced power potential. They are well-suited for street performance, drag racing, and track applications where reliable high-RPM operation and thermal stability are critical.

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.