The Kubota D1503 is a 1.5 L (1,499 cc, 91.44 cu·in) natural aspirated three-cylinders four-stroke liquid-cooled internal combustion vertical diesel engine, manufactured by Kubota for general-purpose applications.
An 83.0 mm (3.27 in) cylinder bore and an 92.4 mm (3.64 in) piston stroke give the D1503 engine a total of 1,499 cc of displacement. The compression ratio rating is 23.0:1.
The D1503-M-E engine produced 31.0 PS (22.8 KW; 30.5 HP) at 2,800 rpm of the net (intermittent) horsepower and 27.0 PS (19.8 KW; 26.5 HP) at 2,800 rpm of net (continuous) horsepower.
The Kubota D1503-M-E features:
- Spherical type combustion chamber (E-TVCS)
- Bosch mini type fuel injection pump
- Centrifugal mechanical governor
- Forced lubrication by trochoid pump
- Liquid cooling system forced circulation with water pump
- Electric starter (12V, 1.4 kW)
- Charing generator (12V, 480 W)
General information
Engine Specifications | |
Engine model | D1503-M-E |
Engine type | 4-stroke, vertical, three-cylinders |
Displacement | 1.5 L, 1,499 cm3, (91.44 cu·in) |
Max. horsepower | Net (intermittent): 31.0 PS (22.8 KW; 30.5 HP) at 2,800 rpm Net (continuous): 27.0 PS (19.8 KW; 26.5 HP) at 2,800 rpm |
Max. torque | – |
Cooling system | Liquid-cooled |
Lubricating system | Forced lubrication by pump |
Combustion chamber | Spherical type |
Fuel injection pump | Bosch mini type |
Injection nozzle | – |
Fuel used | Diesel fuel No.2-D |
Starting system | Electric starter (12V, 1.4 kW) |
Starting support device | Glow plug in combustion chamber |
Governor | Centrifugal mechanical governor |
PTO shaft rotation | Counterclockwise (from PTO shaft side) |
Dimensions (L x W X H) | 572 x 507 x 643 mm (22.5 x 20.0 x 25.3 in) |
Dry weight | 148.0 kg (326.0 lbs) |
Cylinder Block and Head
Cylinder block | |
Compression ratio: | 23.0:1 |
Cylinder bore: | 83.0 mm (3.27 in) |
Piston stroke: | 92.4 mm (3.64 in) |
Cylinder internal diameter (standard): | 83.000-83.022 mm (3.2677-3.2686 in) |
Number of piston rings (compression / oil): | 2/1 |
Connecting rod small end diameter (standard): | 25.025-25.040 mm (0.9852-0.9858 in) |
Piston pin diameter: | 25.002-25.011 mm (0.9843-0.9847 in) |
Side clearance (Second): | 0.093-0.120 mm (0.0037-0.0047 in) |
Side clearance (Oil): | 0.020-0.060 mm (0.0008-0.0023 in) |
Ring end gap (Top): | 0.200-0.350 mm (0.0080-0.0138 in) |
Ring end gap (Second): | 0.300-0.450 mm (0.0118-0.0177 in) |
Ring end gap (Oil): | 0.250-0.450 mm (0.0099-0.0177 in) |
Number of main bearings: | 4 |
Crankshaft main journal diameter: | S/n below 3R9999: 51.921-51.940 mm (2.0441-2.0449 in) S/n above 3S0001: 59.921-59.940 mm (2.3590-2.3598 in) |
Crankpin journal diameter: | 46.959-46.975 mm (1.8487-1.8494 in) |
Cylinder head | |
Valves: | 2 (6 valves in total) |
Valve seat width (INTAKE): | 2.120 mm (0.0835 in) |
Valve seat width (EXHAUST): | 2.120 mm (0.0835 in) |
Value seat angle (INTAKE): | 60° |
Value seat angle (EXHAUST): | 45° |
Value face angle (INTAKE): | 60° |
Value face angle (EXHAUST): | 45° |
Valve steam diameter (INTAKE): | 7.960-7.975 mm (0.3134-0.3140 in) |
Valve steam diameter (EXHAUST): | 7.960-7.975 mm (0.3134-0.3140 in) |
Valve spring free length (INTAKE): | 41.7-42.2 mm (1.6417-1.6614 in) |
Valve spring free length (EXHAUST): | 41.7-42.2 mm (1.6417-1.6614 in) |
Camshaft cam height (INTAKE): | 33.900 mm (1.3346 in) |
Camshaft cam height (EXHAUST): | 33.900 mm (1.3346 in) |
Camshaft journal diameter : | 39.934-39.950 mm (1.5722-1.5728 in) |
Tightening torque
Tightening torque specs | |
Rocker arm bracket nuts: | 23.5-27.5 Nm (2.4-2.8 kgf-m, 17.4-20.3 lb-ft) |
Cylinder head: | 93.1-98.0 Nm (9.5-10.0 kgf-m, 68.7-72.3 lb-ft) |
Nozzle holder assembly: | 49.0-68.6 Nm (5.0-7.0 kgf-m, 36.2-50.6 lb-ft) |
Connecting rod screw: | 44.1-49.0 Nm (4.5-5.0 kgf-m, 32.5-36.2 lb-ft) |
Flywheel: | 98.1-107.9 Nm (10.0-11.0 kgf-m, 72.3-79.6 lb-ft) |
Main bearing case screw 1: | 46.1-50.9 Nm (4.7-5.2 kgf-m, 34.0-37.6 lb-ft) |
Main bearing case screw 2: | 68.6-73.5 Nm (7.0-7.5 kgf-m, 50.6-54.2 lb-ft) |
Service Data
Engine | |
Maximum speed: | 3,000 rpm |
Idle speed: | 700-750 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: | 0.18-0.22 mm (0.0071-0.0087 in) |
Exhaust valve clearance: | 0.18-0.22 mm (0.0071-0.0087 in) |
Oil system | |
Lubrication system: | Forced lubrication by trochoid pump |
Oil type: | API CD or better |
Oil capacity: | Oil pan depth 90.0 mm (3.54 in): 5.6 L (1.5 US gal, 1.2 Imp. gal) Oil pan depth 124.0 mm (4.88 in): 7.0 L (1.8 US gal, 1.5 Imp. gal) |
Oil filter: | Full flow paper filter (cartrige type) |
Fuel system | |
Fuel injection pump | Bosch mini pump |
Injection timing: | 17-19° B.T.D.C. |
Fuel injection pressure | 13.73-14.7 MPa (140-150 kgf/cm2, 1991-2133 psi) |
Cooling system | |
Type: | Pressurized radiator (not included in the basic engine), forced circulation with water pump |
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 capacity: | 5.5 liters (1.5 US gal, 1.2 Imp. gal) |
Electrical system | |
Battery: | 12V, 70-80 Ah or equivalent |
Alternator brush Length (std/min): | 10.5 mm (0.4130 in) / 8.4 mm (0.3310 in) |
Glow plug resistance: | Approx 0.9 Ω |
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