DSS Racing Gen III Hemi FX Series Forged Piston Set

Fits Chrysler, Dodge, Jeep, Ram 6.1L SRT8 Models

1-6847-4090 / 2-6847-4090 / 3-6847-4090 / K1-6847-4090 / K2-6847-4090 / K3-6847-4090

Overview:

The DSS Racing Gen III Hemi FX Series Forged Piston Set is engineered specifically for the Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 engines. Designed to replace factory pistons, this set offers enhanced strength and durability for high-performance applications. Ideal for enthusiasts and professional builders looking to maximize engine reliability and power output, these pistons provide a perfect balance of lightweight construction and robust design.

With a 4.090" bore size and a compact dome top design, these pistons support increased compression ratios and improved combustion efficiency. Whether you are rebuilding your 6.1L SRT8 or upgrading for forced induction or naturally aspirated performance, this piston set delivers consistent quality and precision fitment.

Key Features:

Built to meet the demands of high-performance Mopar Hemi engines, the DSS Racing FX Series pistons include several advanced features:

• Forged construction for superior strength and durability under extreme conditions
• +4cc dome top design to optimize compression ratio and combustion efficiency
• Pin diameter of .927" compatible with full-floating or press-fit wrist pins
• Ring groove dimensions of 1.2mm/1.2mm/3mm for reliable ring sealing and reduced blow-by
• Comp height of 1.21" to maintain proper deck clearance and piston-to-valve clearance
• Compatible with 3.578" stroke crankshafts and 6.243" connecting rods
• Available in multiple dish volumes (65cc, 74cc, 85cc) to tailor compression ratios from 9.59:1 to 12.06:1
• Precision machining ensures consistent bore fit and balanced piston weight

Construction & Design:

These pistons are crafted from high-grade forged aluminum alloy, providing an excellent strength-to-weight ratio essential for high-revving engines. The forging process enhances grain structure, resulting in pistons that resist cracking and deformation under thermal and mechanical stress. The dome top design with varying dish volumes allows builders to customize compression ratios to suit different performance goals, whether for street, strip, or track use.

The piston pin bore is engineered to accept either full-floating or press-fit pins, offering flexibility depending on engine build preferences. Ring grooves are precision-cut to accommodate standard 1.2mm top and second rings with a 3mm oil ring, ensuring optimal sealing and oil control. Overall, the design focuses on durability, performance, and compatibility with factory and aftermarket components.

Installation & Fitment:

This piston set is designed as a direct fit for most Chrysler, Dodge, Jeep, and Ram vehicles equipped with the 6.1L SRT8 Hemi engine. Installation requires standard engine rebuild procedures, including proper honing of the cylinder bores to the 4.090" specification. The pistons are compatible with factory connecting rods and crankshaft stroke of 3.578". Builders should verify piston-to-valve clearance and deck height during assembly to ensure optimal performance and reliability.

No special modifications are typically necessary, making these pistons an excellent upgrade for both OEM rebuilds and performance engine builds.

What's Included:

• Set of forged pistons sized for 4.090" bore
• Compatible wrist pin bores for full-floating or press-fit pins
• Precision-machined ring grooves for 1.2/1.2/3mm ring sets

Ideal For:

This piston set is ideal for automotive enthusiasts, engine builders, and professional shops upgrading or rebuilding the 6.1L SRT8 Hemi engine. It suits applications ranging from street performance to drag racing and road course use, providing enhanced strength and reliability over stock pistons. The ability to select different dish volumes allows customization of compression ratios to match specific power goals and fuel types.

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.