DSS Racing FX Series Forged Piston Set
Fits Most Chrysler / Dodge / Jeep / Ram 6.4L 392 Models
1-6840-4055C / 2-6840-4055C / 3-6840-4055C / K1-6840-4055C / K2-6840-4055C / K3-6840-4055C
Overview:
The DSS Racing Gen III Hemi FX Series Forged Piston Set is engineered for enthusiasts and professional builders seeking durable, high-performance pistons for Chrysler, Dodge, Jeep, and Ram 6.4L 392 engines. Designed to fit most 6.4L 392 small block Mopar Hemi Gen III engines, these pistons offer a perfect balance of strength, precision, and reliability for street, strip, or track applications.
With a 4.055" bore size and a compact 1.21" compression height, these forged pistons provide excellent compatibility with factory and aftermarket components. Their flat-top design with a -1.5cc volume optimizes combustion efficiency and power output, making them ideal for high-performance builds that demand consistent results under extreme conditions.
Key Features:
These pistons incorporate advanced engineering and quality materials to deliver superior performance and longevity. Key features include:
- Forged construction for enhanced strength and durability under high stress
- Flat-top piston design with a -1.5cc volume for optimized combustion chamber dynamics
- Pin diameter of .927" compatible with full-floating or press-fit configurations
- Ring groove dimensions of 1.2mm/1.2mm/3mm to accommodate high-performance piston rings
- Stroke compatibility of 3.720" and connecting rod length of 6.2" for precise engine geometry
- Available in multiple compression volumes (65cc, 74cc, 85cc) to suit various compression ratio requirements
- Designed specifically for the 384 Small Block Mopar Hemi Gen III platform
- Precision manufacturing ensures tight tolerances and consistent fitment
Construction & Design:
The DSS Racing FX Series pistons are crafted from high-grade forged aluminum alloy, providing an optimal combination of lightweight strength and thermal conductivity. This material choice helps reduce reciprocating mass while maintaining the structural integrity needed for high-RPM and high-boost applications. The pistons feature a carefully engineered flat-top profile with a slight dish to fine-tune compression ratios, enhancing combustion efficiency and power delivery.
Each piston is machined with precision ring grooves and pin bores to ensure proper sealing and minimal friction. The option for full-floating or press-fit wrist pins allows builders to tailor the setup to their specific engine build and performance goals. The robust design supports aggressive tuning and extended durability in demanding environments.
Installation & Fitment:
These pistons are designed to fit most Chrysler, Dodge, Jeep, and Ram 6.4L 392 Hemi Gen III engines with a 4.055" bore. Installation requires standard engine assembly procedures, and the pistons are compatible with factory or aftermarket rods featuring a 6.2" length and a 3.720" stroke. Builders should verify clearances and ring end gaps during installation to ensure optimal performance and longevity.
No major modifications are typically necessary, making these pistons a direct replacement or upgrade option for performance rebuilds and engine refreshes.
What's Included:
- Set of forged pistons (quantity as per kit selection)
- Compatible wrist pins (.927" diameter)
- Precision-machined ring grooves ready for high-performance piston rings
Ideal For:
- Performance engine builders upgrading 6.4L 392 Hemi Gen III platforms
- Street and strip enthusiasts seeking reliable forged pistons for high horsepower applications
- Motorsport participants requiring durable components for drag racing, road racing, or off-road use
- Engine rebuilders aiming to improve compression ratios and combustion efficiency
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.
DSS Racing Gen III Hemi FX Series Forged Piston Set 4.055" Bore: Fits most Hemi Models
- Unit price
- /per
What does the Available to Promise date mean?
ETA stands for Estimated Time of Arrival. The date shown is calculated using our Available-to-Promise (ATP) system, which tracks real-time supplier commitments to determine when a product is expected to be available for delivery. Specifically, the date is calculated by adding 9 business days from the date a supplier has committed to ship the product, representing a worst-case scenario for when we can expect to receive inventory.
Please note: The ETA is an estimate, not a guarantee. While we work closely with our suppliers to keep dates as accurate as possible, delays due to shipping carriers, weather, customs, or supplier-side issues may occasionally push the actual arrival beyond the date shown. Likewise, inventory may arrive sooner than the ETA in many cases. If you would like to be notified for when this item arrives, sign up for our back in stock notifications!
1-6840-4055C DSS Racing 11-25 Chrysler / Dodge / Jeep / Ram 6.4L 392 Gen III Hemi FX Series Forged Piston Set. Engineered for high-performance 6.4L 392 models, these forged pistons offer exceptional strength and durability. Featuring a 4.055" bore, 1.21" compression height, and a -1.5cc flat top design, they optimize combustion efficiency and power output. Compatible with full-floating or press-fit pins, the set supports precise ring groove dimensions for superior sealing. Ideal for enthusiasts seeking reliable, high-quality pistons to enhance engine performance and longevity.
FREE GROUND SHIPPING
MADE IN THE USA
Adding product to your cart
DSS Racing FX Series Forged Piston Set
Fits Most Chrysler / Dodge / Jeep / Ram 6.4L 392 Models
1-6840-4055C / 2-6840-4055C / 3-6840-4055C / K1-6840-4055C / K2-6840-4055C / K3-6840-4055C
Overview:
The DSS Racing Gen III Hemi FX Series Forged Piston Set is engineered for enthusiasts and professional builders seeking durable, high-performance pistons for Chrysler, Dodge, Jeep, and Ram 6.4L 392 engines. Designed to fit most 6.4L 392 small block Mopar Hemi Gen III engines, these pistons offer a perfect balance of strength, precision, and reliability for street, strip, or track applications.
With a 4.055" bore size and a compact 1.21" compression height, these forged pistons provide excellent compatibility with factory and aftermarket components. Their flat-top design with a -1.5cc volume optimizes combustion efficiency and power output, making them ideal for high-performance builds that demand consistent results under extreme conditions.
Key Features:
These pistons incorporate advanced engineering and quality materials to deliver superior performance and longevity. Key features include:
- Forged construction for enhanced strength and durability under high stress
- Flat-top piston design with a -1.5cc volume for optimized combustion chamber dynamics
- Pin diameter of .927" compatible with full-floating or press-fit configurations
- Ring groove dimensions of 1.2mm/1.2mm/3mm to accommodate high-performance piston rings
- Stroke compatibility of 3.720" and connecting rod length of 6.2" for precise engine geometry
- Available in multiple compression volumes (65cc, 74cc, 85cc) to suit various compression ratio requirements
- Designed specifically for the 384 Small Block Mopar Hemi Gen III platform
- Precision manufacturing ensures tight tolerances and consistent fitment
Construction & Design:
The DSS Racing FX Series pistons are crafted from high-grade forged aluminum alloy, providing an optimal combination of lightweight strength and thermal conductivity. This material choice helps reduce reciprocating mass while maintaining the structural integrity needed for high-RPM and high-boost applications. The pistons feature a carefully engineered flat-top profile with a slight dish to fine-tune compression ratios, enhancing combustion efficiency and power delivery.
Each piston is machined with precision ring grooves and pin bores to ensure proper sealing and minimal friction. The option for full-floating or press-fit wrist pins allows builders to tailor the setup to their specific engine build and performance goals. The robust design supports aggressive tuning and extended durability in demanding environments.
Installation & Fitment:
These pistons are designed to fit most Chrysler, Dodge, Jeep, and Ram 6.4L 392 Hemi Gen III engines with a 4.055" bore. Installation requires standard engine assembly procedures, and the pistons are compatible with factory or aftermarket rods featuring a 6.2" length and a 3.720" stroke. Builders should verify clearances and ring end gaps during installation to ensure optimal performance and longevity.
No major modifications are typically necessary, making these pistons a direct replacement or upgrade option for performance rebuilds and engine refreshes.
What's Included:
- Set of forged pistons (quantity as per kit selection)
- Compatible wrist pins (.927" diameter)
- Precision-machined ring grooves ready for high-performance piston rings
Ideal For:
- Performance engine builders upgrading 6.4L 392 Hemi Gen III platforms
- Street and strip enthusiasts seeking reliable forged pistons for high horsepower applications
- Motorsport participants requiring durable components for drag racing, road racing, or off-road use
- Engine rebuilders aiming to improve compression ratios and combustion efficiency
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.
-
-
YEARMAKEMODELSUBMODEL2012 - 2024Chrysler3006.4L 3922011 - 2023DodgeChallenger6.4L 3922011 - 2023DodgeCharger6.4L 3922018 - 2025DodgeDurango6.4L 3922015 - 2021JeepGrand Cherokee6.4L SRT2012 - 2014JeepGrand Cherokee6.4L SRT82022 - 2024JeepGrand Wagoneer6.4L 3922021 - 2025JeepWrangler6.4L 3922013 - 2025Ram25006.4L 3922013 - 2025Ram35006.4L 392
-
Standard shipping
Free Standard Shipping on orders over $300. Select “Free Shipping” at checkout. *Exclusions apply on oversized and freight items.
Free Easy Returns
Need to return an item? We make it easy. Email us and we'll send you a free return label with instructions on how to return.
-
Compression Ratio Calculator
Calculate your engine's compression ratio and CID
-
Features Piston Series E SeriesE SX SeriesSX 1-FX Series1-FX 2-FX Series2-FX 3-FX Series3-FX Broached pin oiling slots Drilled, forced wrist pin oiling Forged drain-back windows Drilled bottom ring land intersecting oil groove drain-backs Slightly larger, deeper valve reliefs than OEM CNC machined valve reliefs for moderate performance heads and cam combinations Larger, deeper CNC valve reliefs for more aggressive cylinder head and cam combinations Premium Aircraft spec. 4032 low expansion alloy Premium Aircraft spec. 2618 alloy Blower, Turbo, NOS ready Brushed piston crown Additional CNC milling for weight reduction Patented "X Groove" skirt for superior cylinder and ring life Thinner/shallower ring grooves for max ring seal Low volume contact reduction grooves 2nd ring land accumulator groove prevents flutter 3rd ring land scraper relief Oil ring groove relief reservoir Inner and outer pin boss weight reduction Tighter crown thickness control for lighter parts Dynamic skirt milling for consistent weight Diamond-turned high strength skirts High-strength piston pins Extreme Duty XR wrist pins Horizontal Gas Ports enhance ring seal Forged and machined in the USA
Standard shipping
Free Standard Shipping on orders over $300. Select “Free Shipping” at checkout. *Exclusions apply on oversized and freight items.
Free Easy Returns
Need to return an item? We make it easy. Email us and we'll send you a free return label with instructions on how to return.
Compression Ratio Calculator
Calculate your engine's compression ratio and CID
| Features | Piston Series | ||||
|---|---|---|---|---|---|
| E SeriesE | SX SeriesSX | 1-FX Series1-FX | 2-FX Series2-FX | 3-FX Series3-FX | |
| Broached pin oiling slots | |||||
| Drilled, forced wrist pin oiling | |||||
| Forged drain-back windows | |||||
| Drilled bottom ring land intersecting oil groove drain-backs | |||||
| Slightly larger, deeper valve reliefs than OEM | |||||
| CNC machined valve reliefs for moderate performance heads and cam combinations | |||||
| Larger, deeper CNC valve reliefs for more aggressive cylinder head and cam combinations | |||||
| Premium Aircraft spec. 4032 low expansion alloy | |||||
| Premium Aircraft spec. 2618 alloy | |||||
| Blower, Turbo, NOS ready | |||||
| Brushed piston crown | |||||
| Additional CNC milling for weight reduction | |||||
| Patented "X Groove" skirt for superior cylinder and ring life | |||||
| Thinner/shallower ring grooves for max ring seal | |||||
| Low volume contact reduction grooves | |||||
| 2nd ring land accumulator groove prevents flutter | |||||
| 3rd ring land scraper relief | |||||
| Oil ring groove relief reservoir | |||||
| Inner and outer pin boss weight reduction | |||||
| Tighter crown thickness control for lighter parts | |||||
| Dynamic skirt milling for consistent weight | |||||
| Diamond-turned high strength skirts | |||||
| High-strength piston pins | |||||
| Extreme Duty XR wrist pins | |||||
| Horizontal Gas Ports enhance ring seal | |||||
| Forged and machined in the USA | |||||