DSS Racing FX Series Forged +4cc Dome Top Pistons

Chrysler / Dodge / Jeep / Ram 6.2L Hellcat, 6.4L 392 & Trackhawk

1-6817-4125 / 2-6817-4125 / 3-6817-4125 / K1-6817-4125 / K2-6817-4125 / K3-6817-4125

Overview:

The DSS Racing FX Series Forged +4cc Dome Top Pistons are precision-engineered components designed specifically for Mopar Gen III Hemi 6.2L and 6.4L engines. Featuring a 4.125" bore size, these pistons offer a +4cc dome top design that enhances compression ratios and combustion efficiency. Ideal for performance enthusiasts and professional builders, these pistons provide a reliable upgrade for high-output applications, including Hellcat, 392, and Trackhawk engines.

Built to withstand the rigors of high-performance use, these pistons support increased power and durability while maintaining tight tolerances for optimal engine balance and longevity. Whether you're building a street machine or a race-ready engine, DSS Racing FX Series pistons deliver the strength and precision needed for serious performance gains.

Key Features:

These pistons incorporate advanced design and manufacturing techniques to ensure superior performance and reliability. Key features include:

• Forged construction for exceptional strength and durability under high stress
• +4cc dome top design to increase compression ratio and improve combustion
• Compatible with 4.125" bore Mopar Gen III Hemi 6.2L and 6.4L engines
• Pin diameter of .927" with options for full-floating or press-fit configurations
• Ring groove dimensions of 1.2/1.2/3mm to accommodate high-performance piston rings
• Comp height of 1.12" for precise deck clearance and piston-to-valve clearance
• Designed for use with a 4.050" stroke and 6.125" connecting rods
• Available in multiple compression volumes (65cc, 74cc, 85cc) to tailor compression ratios from 10.88:1 up to 13.71:1
• Optimized dome shape for improved flame propagation and power output

Construction & Design:

DSS Racing FX Series pistons are forged from high-grade aluminum alloy, providing an excellent balance of lightweight construction and structural integrity. The forging process enhances grain flow and material density, resulting in pistons that resist cracking, scuffing, and thermal fatigue. The dome top design increases the combustion chamber volume, allowing for higher compression ratios without compromising piston strength.

Each piston is CNC-machined to exacting tolerances, ensuring consistent fitment and performance. The ring grooves are precision-cut to accommodate performance rings that maintain optimal sealing under extreme conditions. The option for full-floating or press-fit wrist pins allows builders to customize the piston assembly based on their specific engine build preferences.

Installation & Fitment:

These pistons are engineered as direct replacements for Chrysler, Dodge, Jeep, and Ram 6.4L 392, 6.2L Hellcat, and Trackhawk engines with a 4.125" bore. Installation requires standard engine assembly procedures, and no major modifications are typically necessary when upgrading from factory pistons. Proper ring end gap and clearance measurements should be verified during installation to ensure optimal performance and longevity.

Due to the +4cc dome design, these pistons slightly increase compression ratios, so tuning adjustments may be required to optimize engine management and prevent detonation. They are compatible with existing connecting rods and crankshaft stroke specifications listed.

What's Included:

• Set of forged +4cc dome top pistons (quantity as per SKU selection)
• Wrist pins (full-floating or press-fit depending on configuration)
• Precision-cut piston rings (1.2mm top and second rings, 3mm oil ring)
• Installation instructions and technical specifications

Ideal For:

These DSS Racing FX Series pistons are ideal for performance engine builders, racers, and enthusiasts seeking to increase power output and reliability in Mopar Gen III Hemi 6.2L and 6.4L engines. They are well-suited for street performance upgrades, track use, and forced induction setups where enhanced compression and durability are critical. Builders looking to optimize combustion efficiency and engine response will benefit from the precision engineering and robust construction of these pistons.

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.