Piston Kit

Piston Kits for Cummins 4B Engines

Diesel Pro Power offers a complete selection of Cummins 4B piston kits designed to fit a wide range of CPL numbers and compression ratios. Each kit includes the piston, piston pin, and matching components engineered to meet or exceed OEM specifications. These kits are built for performance, longevity, and ease of installation in both marine and industrial diesel applications.

Engine Compatibility and CPL Coverage

The Cummins 4B is a 3.9L inline four-cylinder diesel engine used in a broad variety of heavy-duty machinery, marine vessels, and stationary equipment. Because Cummins designed the 4B platform with many configuration options, each piston kit is matched to a specific group of CPLs (Control Parts Lists) to ensure precise fitment and combustion performance. Whether you're working with a naturally aspirated or turbocharged version, you'll find a piston kit designed for your engine’s specifications.

Compression Ratio Options for Cummins 4B Piston Kits

15.3:1 Compression Ratio Piston Kits

This configuration is ideal for engines requiring slightly lower combustion pressure, often for applications prioritizing durability and lower emissions under continuous load. The 15.3:1 piston kit fits CPL numbers such as:

1975, 2197, 2205, 2208, 2956, 8104, 8457

Use this kit when your 4B engine is used in steady-state power generation, marine auxiliary power, or similar applications.

16.5:1 Compression Ratio Piston Kits

A mid-range compression piston designed to balance power and efficiency. This piston kit offers reliable cold starts and combustion characteristics for varied operating environments. CPLs supported include:

594, 595, 599, 600, 696, 698, 710, 713, 715, 741, 742, 792, 793, 826, 834, 912, 937, 940, 961, 962, 983, 998, 1173, 1174, 1209, 1278, 1518, 1520, 1523, 1524, 1525, 1581, 2050, 2377, 2530, 2891, 8206

Ideal for marine and industrial 4B engines that require strong mid-load performance without extreme combustion temperatures.

17.3:1 Compression Ratio Piston Kits

This high-compression option is designed for optimal fuel atomization and power output. If your 4B engine is used in high-torque applications such as marine propulsion or heavy mechanical loads, the 17.3:1 ratio provides excellent thermal efficiency. Supported CPLs include:

591, 596, 681, 691, 714, 721, 725, 791, 802, 843, 845, 895, 960, 981, 999, 1172, 1259, 1312, 1320, 1403, 1433, 1522, 1608, 1932

17.5:1 Compression Ratio Piston Kits

The highest standard compression option available for the Cummins 4B engine. These pistons are engineered for engines running at full load with maximum torque output. Use this configuration for commercial vessels or industrial units requiring optimal thermal performance. Compatible CPLs include:

953, 970, 1165, 1247, 1313, 1322, 1408, 1570, 1613, 1638, 1928
597, 690, 692, 712, 716, 727, 729, 730, 761, 762, 763, 804, 807, 817, 856, 857, 858, 938, 943, 947, 948, 949, 950, 971, 994, 1160, 1163, 1168, 1189, 1201, 1202, 1207, 1209, 1245, 1246, 1266, 1268, 1277, 1279, 1287, 1288, 1289, 1440, 1508, 1554, 1601, 1627, 1631, 1659, 1685, 2021, 2049, 2272, 2273, 2340, 2413, 2414

Standard Fitment Piston Kits (No Compression Ratio Specified)

These piston kits offer a general replacement solution for a wide range of CPLs and engine versions. They’re especially useful when the original CPL is no longer visible or if you're performing a standard top-end rebuild. CPL compatibility includes:

1965, 1966, 1967, 2109, 2144, 2302, 2351, 2359, 2396, 2478, 2623, 8442, 1071, 1961, 1962, 2242, 2296, 2372, 2373, 2417, 2551, 2868, 3868, 1902, 1948, 2014, 2015, 2016, 2071, 2122, 2125, 2292, 8444
1551, 1552, 1553, 1744, 1839, 1914, 1915, 1916, 2000, 2001, 2013, 2023, 2175, 2195, 2243, 2249, 2252, 2253, 2347, 2348, 2375, 3219

Supporting Components for Cummins 4B Pistons

To complete your engine rebuild or piston replacement, Diesel Pro Power also offers essential components and accessories that integrate with our piston kits.

Salvage Sleeves for Cummins 4B

These sleeves are designed to bring worn engine blocks back to standard size. Ideal for rebuilders seeking to restore block integrity without full block replacement.

Compatible with 4B, 4BT, 6B, 6BT, ISB, and QSB series blocks
Used to correct bore damage or wear while maintaining factory tolerances

Piston Ring Sets for Cummins 4B

Each ring set is precision-matched to the piston it serves. We offer multiple options based on piston type and groove geometry.

Standard sets: One set per piston, with OEM-quality tension and sealing profiles
8MM TRL piston rings: Designed for high-efficiency combustion control
Type E piston rings: Optimized for specific piston designs used in select CPL configurations

Ensure you choose the correct ring set to match your piston kit for optimal sealing, oil control, and longevity.

Gasket Support for Piston Installations

When replacing pistons in the Cummins 4B engine, it's strongly recommended to also install a fresh upper gasket set to ensure proper sealing and long-term performance. Our kits contain:

Head gasket
Intake and exhaust manifold gaskets
Valve cover gaskets
Injector sealing washers
Turbo gaskets and seals

All gasket materials are engineered for diesel-grade compression and temperature cycling.

Why Buy Cummins 4B Piston Kits from Diesel Pro Power?

40,000+ satisfied customers worldwide
Fast shipping on all piston kits and related components
Expert support for engine CPL verification and selection
Inventory matched for marine, industrial, and power generation 4B engines
OEM-compliant quality, backed by proven industry reliability

Applications for Cummins 4B Piston Kits

Diesel Pro’s piston kits support a wide range of Cummins 4B engine applications, including:

Marine auxiliary power units
Industrial air compressors
Power generation skid units
Forklifts, loaders, and off-road machinery
Stationary diesel engines for pumping, drilling, and backup power

Regardless of your environment—saltwater, high humidity, industrial heat—we provide piston kits that withstand the most demanding conditions.