Kubota D902-E4B

Kubota D902-E4BThe Kubota D902-E4B is an 898 cc (54.8 cu·in) natural aspirated three-cylinders four-stroke liquid-cooled internal combustion vertical diesel engine, manufactured by Kubota for general-purpose applications.

A 72.0 mm (2.83 in) cylinder bore and 73.6 mm (2.9 in) piston stroke give the D902-E4B engine a total of 898 cc of displacement. The compression ratio rating is 24.0:1.

The D902-E4B engine produced 23.8 PS (17.5 kW; 23.5 HP) at 3,600 rpm of net (intermittent) horsepower, 25.2 PS (18.5 kW; 24.8 HP) at 3,600 rpm of gross (intermittent) horsepower and 56.1 Nm (5.72 kg·m; 41.4 lbf·ft) at 2,600 rpm of torque.

The Kubota D902-E4B features:

  • Spherical type combustion chamber
  • Bosch MD-type mini fuel injection pump
  • Bosch throttle type injection nozzle
  • Centrifugal ball mechanical governor
  • Forced lubrication by pump
  • Liquid cooling system
  • Electric starter (12V, 1.2 kW)
  • Charging alternator (12V, 480 W)

General information

Engine Specifications
Engine modelD902-E4B
Engine type4-stroke, vertical, three-cylinders
Displacement898 cm3, (54.8 cu·in)
Max. horsepower Gross (intermittent): 25.2 PS (18.5 kW; 24.8 HP) at 3,600 rpm
Net (intermittent): 23.8 PS (17.5 KW; 23.5 HP) at 3,600 rpm
Net (continuous): 20.7 PS (15.2 KW; 20.4 HP) at 3,600 rpm
Max. torque56.1 Nm (5.72 kg·m; 41.4 lbf·ft) at 2,600 rpm
Emission typeEPA/CARB Tier 4 (NRTC/NTE test mode) + EU Stage V
Cooling systemLiquid-cooled
Lubricating systemForced lubrication by pump
Combustion chamberSpherical type (E-TVCS)
Fuel injection pumpBosch MD type mini pump
Injection typeIndirect injection
Injection nozzleBosch throttle type
Fuel usedDiesel fuel No.2-D
Starting systemElectric starter (12V, 1.2 kW)
Starting support deviceGlow plug in combustion chamber
GovernorCentrifugal ball mechanical governor
PTO shaft rotationCounterclockwise (from PTO shaft side)
Dimensions (L x W X H)467 x 421 x 544 mm (18.4 x 16.6 x 21.4 in)
Dry weight72.0 kg (158.7 lbs)

Cylinder Block and Head

Cylinder block
Compression ratio:24.0:1
Cylinder bore:72.0 mm (2.83 in)
Piston stroke:73.6 mm (2.9 in)
Cylinder internal diameter (standard):72.000-72.019 mm (2.8346-2.8354 in)
Number of piston rings (compression / oil):2/1
Connecting rod small end diameter (standard):20.025-20.040 mm (0.7884-0.789 in)
Piston pin diameter:20.002-20.040 mm (0.7875-0.789 in)
Side clearance (Second):0.090-0.120 mm (0.0035-0.0047 in)
Side clearance (Oil):0.040-0.080 mm (0.0016-0.0031 in)
Ring end gap (Top):0.150-0.300 mm (0.0059-0.0110 in)
Ring end gap (Second):0.350-0.500 mm (0.0138-0.0197 in)
Ring end gap (Oil):0.150-0.300 mm (0.0059-0.0110 in)
Number of main bearings:4
Crankshaft main journal diameter:43.934-43.950 mm (1.72969-1.73032 in)
Crankpin journal diameter:33.959-33.975 mm (1.337-1.3376 in)
Cylinder head
Valves:2,(6 valves in total)
Valve timing (INTAKE): Open: 20° Before T.D.C.
Close: 45° After B.D.C.
Valve timing (EXHAUST): Open: 50° Before B.D.C.
Close: 15° After T.D.C.
Valve seat width (INTAKE):2.120 mm (0.0835 in)
Valve seat width (EXHAUST):2.120 mm (0.0835 in)
Value seat angle (INTAKE):45°
Value seat angle (EXHAUST):45°
Valveface angle (INTAKE):45°
Valveface angle (EXHAUST):45°
Valve steam diameter (INTAKE):5.968-5.980 mm (0.2349-0.2354 in)
Valve steam diameter (EXHAUST):5.968-5.980 mm (0.2349-0.2354 in)
Valve spring free length (INTAKE):31.6 mm (1.2441 in)
Valve spring free length (EXHAUST):31.6 mm (1.2441 in)
Tappet outer diameter:17.966-17.984 mm (0.7073-0.7080 in)
Rocker arm shaft outer diameter:10.473-10.484 mm (0.4123-0.4127 in)
Camshaft lobe height (INTAKE):26.880 mm (1.0583 in)
Camshaft lobe height (EXHAUST):26.880 mm (1.0583 in)
Camshaft journal diameter :32.934-32.950 mm (1.2966-1.2972 in)

Tightening torque

Tightening torque specs
Head cover cap nuts (M6x1.0):3.9-5.3 Nm (0.4-0.6 kgf-m, 2.9-4.3 lb-ft)
Head bolts (M8x1.25):39.2-44.1 Nm (4.0-4.5 kgf-m, 28.9-32.5 lb-ft)
Main bearing case bolts 1 (M6x1.0):12.7-15.7 Nm (1.3-1.6 kgf-m, 9.4-11.6 lb-ft)
Main bearing case screw 2 (M7x1.0):26.5-30.4 Nm (2.7-3.1 kgf-m, 19.5-22.4 lb-ft)
Flywheel bolts (M10x1.25):53.9-58.8 Nm (5.5-6.0 kgf-m, 39.8-43.4 lb-ft)
Connecting rod bolts (M7x0.75):26.5-30.4 Nm (2.7-3.1 kgf-m, 19.5-22.4 lb-ft)
Rocker arm bracket nuts (M6x1.0):9.81-11.28 Nm (1.0-1.15 kgf-m, 7.23-8.32 lb-ft)
Idle gear shaft bolts (M6x1.0):9.8-11.3 Nm (1.00-1.15 kgf-m, 7.2-8.3 lb-ft)
Idle gear shaft screws (M6x1.0):9.8-11.3 Nm (1.00-1.15 kgf-m, 7.2-8.3 lb-ft)
Glow plugs (M8x1.0):7.8-14.7 Nm (0.8-1.5 kgf-m, 5.8-10.8 lb-ft)
Nozzle holder assembly (M20x1.5):49.0-68.6 Nm (5.0-7.0 kgf-m, 36.2-50.6 lb-ft)
Nozzle holder and nozzle retaining nut:58.8-78.5 Nm (6.0-8.0 kgf-m, 43.4-57.9 lb-ft)
Injection pipe retaining nuts:24.5-34.3 Nm (2.5-3.5 kgf-m, 18.1-25.3 lb-ft)

Service Data

Maximum speed:3,800 rpm
Idle speed:900-1000 rpm
Cylinder compression:36.0-41.0 kgf/cm2 (3.53-4.02 MPa, 512-583 psi)
Compression differential limit between cylinders:10% or less
Valve clearance
Intake valve clearance:0.145-0.185 mm (0.0057-0.0073 in)
Exhaust valve clearance:0.145-0.185 mm (0.0057-0.0073 in)
Oil system
Lubrication system:Forced lubrication by pump
Oil type:API CD or CE
Oil capacity:3.7 liters (3.91 US.qts, 3.26 Imp. qts)
Oil filter:Full flow paper filter (cartridge type)
Oil pressure: At idle spped: 98 kPa (1.0 kgf/cm2, 14 psi)
At rated speed: 196-441 kPa (2.0-4.5 kgf/cm2, 29-64 psi)
Fuel system
Fuel injection pumpBosch MD-type mini pump
Injection nozzleBosch throttle type
Injection timing:18.25-19.75° B.T.D.C.
Fuel injection pressure13.73-14.71 MPa (140-150 kgf/cm2, 1991-2133 psi)
Cooling system
Type:Pressurized radiator, forced circulation with water pump (not included in the basic engine)
Thermostat’s valve opening temperature:69.5-72.5°C (157.1-162.5°F)
Temperature at which thermostat completely opens:85°C (185°F)
Coolant capacity3.2 liters (3.38 US.qts, 2.82 Imp. qts)
Electrical system
Battery:12V, 52AH or equivalent
Alternator stator resistance:Less than 1.0 Ω
Alternator rotor resistance:Less than 2.9 Ω
Alternator slip ring:14.4 mm (0.567 in)
Alternator brush Length:10.5 mm (0.413 in)
Alternator (no-load voltage):AC 20V at 5,200 rpm
Glow plug resistance:Approx 0.9 Ω
Author: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.

ATTENTION! Dear visitors, this is an informational database of technical specifications, we are not a parts supplier or a marketplace.

We try to use official documentation and verify the published data, but errors may occur. In addition, specifications of machinery and equipment may vary depending on markets and modifications. We do not recommend the use of this data for spare parts or repairs. Use official service manuals or parts catalogs for your product.

Be the first to comment

Leave a Reply

Your email address will not be published.