Cummins NT855 engine main parts maintenance parameters

First, the cylinder block part

1. Inner diameter of cylinder liner: (standard: 139.68mm-139.73mm)
2. The clearance between the cylinder liner and the lower part of the body: (standard: 0.05mm-0.15mm)
3. The inner diameter of the cylinder bore of the lower part of the machine body: (standard: 155.55mm-155.60mm)
4. Cylinder liner stop step depth: (standard: 8.89mm-8.94mm)
5. Cylinder sleeve end diameter: [standard: 166.662-166.713mm]
6. The inner diameter of the spindle hole: (standard: 120.612mm-120.650mm)

Second, the crankshaft part

1. Main shaft diameter: (standard: 114.262mm-114.30mm)
2. The diameter of the shaft diameter of the connecting rod: (standard: 79.337mm-79.38mm)
3. Crankshaft thrust piece thickness: [standard: 6.22-6.27mm]
4. Crankshaft axial clearance: (standard: 0.18mm-0.44mm wear limit: 0.56)

Third, the connecting rod part

1. The diameter of the big hole of the connecting rod: [standard: 83.114-88.139mm]

[New product: 84.219-84.244mm]

2. Piston pin bushing inner diameter: (standard: 50.825mm-50.838mm wear pole 50.856mm)
3. The outer diameter of the piston skirt: [standard: 139.37-139.40mm wear limit: 139.27mm]

Note: Measurement at 21o

4. Piston pin outer diameter: [standard: 50.768-50.775mm wear limit: 50.762mm]

Four, camshaft and other parts

1. Camshaft shaft diameter outer diameter: [standard: 50.72-50.75mm wear limit: 50.70mm]

[Standard: 63.40-63.42mm wear limit: 63.37mm]

2. Camshaft bushing hole inner diameter (with bushing): (standard: 50.862mm-50.938mm)
3. Rocker bushing inner diameter: [standard 28.562-28.639mm wear limit: 28.666mm]
4. Rocker shaft outer diameter: [standard: 28.52-28.55mm wear limit: 28.50mm]
5. With the outer diameter of the boom shaft: [standard: 0.7485-0.749mm wear limit: 0.748mm]
6. With the arm bushing inner diameter: [standard 19.053-19.078mm wear limit: 19.10mm]
7. Crankshaft axial clearance: [Standard: 0.18-0.43mm wear limit: 0.56mm]
8. Cylinder sleeve protruding height: [Standard: 0.08-0.15mm]
9. Connecting rod side clearance: [standard: 0.114-0.33mm]
10. Injector tappet length: [2-inch camshaft model: 464.57mm]

[21/2 inch camshaft model: 451.49mm]

11. Valve tappet length: [2-inch camshaft model: 466.34mm]

[21/2 inch camshaft model: 454.15mm]

12. Aluminum rocker chamber valve clearance: [intake valve: 0.28mm exhaust valve: 0.58mm]
13. Aluminum rocker chamber injector stroke adjustment data: Torque method stroke: 8.1Nm
14. Aluminum rocker chamber valve clearance: torque method [intake valve: 0.36mm exhaust valve: 0.69mm]

Technical Articles

Camshaft, connecting rod, crankshaft, Cummins, cylinder block, Cylinder Liner, maintenance, NTA855

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