DSS Racing FX Series Forged Piston Set

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

1-6840-4065D / 2-6840-4065D / 3-6840-4065D / K1-6840-4065D / K2-6840-4065D / K3-6840-4065D

Overview:

The DSS Racing Gen III Hemi FX Series Forged Piston Set is engineered specifically for the 6.1L SRT8 engines found in Chrysler, Dodge, Jeep, and Ram vehicles. Designed to meet the demands of high-performance applications, these pistons offer exceptional strength and durability while maintaining optimal weight for improved engine response. Whether you're rebuilding or upgrading your small block Mopar Hemi, this piston set delivers reliable performance and precision fitment.

Ideal for enthusiasts and professional builders alike, these pistons provide a solid foundation for increased power output and engine longevity. Their forged construction ensures they can withstand the rigors of boosted or naturally aspirated setups without compromising reliability.

Key Features:

Built with advanced engineering and precision manufacturing, the DSS Racing FX Series pistons include the following key features:

• Compatible with 4.065" bore size for most Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 engines
• Forged construction for superior strength and durability under high stress
• Flat top design with -1.5cc volume for optimized combustion chamber dynamics
• Comp height of 1.21" for precise piston-to-deck clearance
• .927" wrist pin diameter with options for full-floating or press-fit installation
• Ring groove dimensions of 1.2mm/1.2mm/3mm to accommodate high-performance piston rings
• Designed for a 3.578" stroke and 6.243" connecting rod length, matching factory specifications
• Available in multiple compression ratios: 65cc (11.06:1), 74cc (9.99:1), and 85cc (8.95:1)

Construction & Design:

Each piston in the DSS Racing FX Series is forged from high-grade aluminum alloy, providing an excellent balance of strength and lightweight properties. The forging process enhances the grain structure of the metal, resulting in pistons that resist cracking, scuffing, and thermal fatigue even under extreme operating conditions.

The flat top design with a slight dish volume (-1.5cc) optimizes combustion efficiency and helps control detonation in high-compression setups. Precision machining ensures tight tolerances for piston-to-cylinder wall clearance and ring groove dimensions, promoting consistent sealing and reduced blow-by.

Installation & Fitment:

This piston set is designed as a direct fit for most Chrysler, Dodge, Jeep, and Ram 6.1L SRT8 engines equipped with a 4.065" bore. Installation requires standard engine rebuild procedures, including proper honing and cleaning of the cylinder bores. The wrist pins can be installed as either full-floating or press-fit, depending on your build preference and hardware availability.

Due to the precise engineering and OEM-compatible dimensions, no additional modifications are typically necessary, making these pistons an excellent choice for both performance upgrades and reliable rebuilds.

What's Included:

• Set of forged pistons sized for 4.065" bore
• Wrist pins (.927" diameter) compatible with full-floating or press-fit installation
• Detailed specifications for compression ratios and piston dimensions

Ideal For:

This piston set is ideal for performance enthusiasts, engine builders, and racers seeking a durable and reliable upgrade for their 6.1L SRT8 Hemi engines. Whether you are building a naturally aspirated street machine or a boosted race engine, these pistons provide the strength and precision needed to handle increased power levels while maintaining engine longevity.

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.