Searching for a Cummins 855 Big Cam block? Our OEM 3081283 casting features reinforced counterbores to prevent liner sinking. Fits Kenworth and Komatsu. Request a quote!
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The Cummins NT855 cylinder block (OEM: 3081283) is a heavy-duty cast iron unit compatible with Big Cam III/IV engines.
It features precision-machined counterbores to prevent liner seal failure and fits equipment including Kenworth trucks and Komatsu D85 dozers.
In stock for global export.
We specifically address the legacy issues of the 855 platform, such as counterbore ledge wear. Our blocks undergo strict CNC machining to ensure perfect liner height projection, preventing the dreaded head gasket failures common in high-mileage engines. Ruich Value provides a reliable foundation for your engine rebuild, keeping your heavy machinery operational for decades to come.
| Specification | Value |
|---|---|
| Product Type | Cylinder Block (Bare) |
| Engine Series | NT855 / NTA855 / NH220 |
| Version Compatibility | Big Cam (2.5″) & Small Cam (2.0″) Available |
| Material | High-Tensile Grey Cast Iron |
| Bore Size | 139.7 mm (5.50 in) |
| Counterbore Type | Machined Ledge (Standard/Oversize) |
| OEM Reference | 3081283, 3025282, 3054942 |
| Cross Reference | 855 Big Cam Block, N14 Predecessor |
| Typical Applications | Kenworth W900, Komatsu D85/D155 |
| Weight | Approx. 290 kg (640 lbs) |
| Engine Series | Camshaft Type | Typical Equipment |
|---|---|---|
| Cummins NT855 Big Cam (I, II, III, IV) | 2.5 inch Diameter | Heavy Duty Trucks (Kenworth, Freightliner), Versatile Tractors (875, 895) |
| Cummins NTA855 (Small Cam) | 2.0 inch Diameter | Komatsu Dozers (D85A-18), Older Generators, Marine Vessels |
| Cummins N14 (Select Mechanical) | 2.5 inch (Specific CPLs) | Agricultural Equipment, Construction Machinery |
Ruich Value supplies a dedicated range of Cummins cylinder blocks, including new aftermarket and remanufactured replacements. Our coverage includes popular engine families such as the 6BT/6BTA, 4BT, ISB, ISX, and NT855 series. For a complete catalog of our Cummins cylinder blocks, please contact our sales team.
| Model | Model | Model | Model |
|---|---|---|---|
| 4B/4BT | ISL/QSL9.3/6LT-9.3 | ISG | ISX/QSX15 |
| 6B/6BT/6D102 | QSC8.3 | ISLE | ISC |
| 6C/6CT (single thermostat) | X15 | K19 | ISDE4.5 |
| 6CT (double thermostat) | NT855 | ISF2.8 | ISDE6.7 |
| 6L/6LT | ISM11 | ISF3.8 | ISB6 E3 |
| ISB4.5 | ISB6.7 | QSB3.3 |
The primary difference lies in the camshaft bore diameter. “Small Cam” blocks (early NH/NT models) use a 2.0-inch camshaft, while “Big Cam” blocks (introduced around 1976) use a 2.5-inch camshaft to improve combustion timing and reduce emissions. Our 3081283 casting is designed for Big Cam applications, but we also stock Small Cam variants. Please confirm your CPL (Control Parts List) number before ordering.
OEM 855 blocks often suffer from counterbore ledge wear, causing the cylinder liner to sink and blow the head gasket. Our aftermarket blocks are cast with a higher-grade iron alloy and feature precision CNC-machined counterbore ledges with tighter tolerances, ensuring proper liner protrusion and eliminating the need for immediate shimming.
Yes, the Komatsu N855 and S6D125 engines share the same block architecture as the Cummins NT855. This cylinder block (OEM 3081283) is fully compatible with Komatsu D85, D155, and PC400 equipment powered by the 855-series engine, provided the camshaft compatibility is verified.
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For Any Inquiries, please feel free to contact us, Our sales teams are always glad to support your business