The Z602-E4B is a 0.6 L (599 cc, 36.5 cu·in) straight-two, water-cooled naturally aspirated vertical diesel engine from the Super-Mini series manufactured by Kubota.
The Kubota Z602-E4B engine has a spherical type сombustion сhamber with glow plug, Bosch MD mini fuel injection pump, and Bosch throttle type injection nozzle.
It has a 72.0 mm (2.83 in) cylinder bore and a 73.6 mm (2.9 in) piston stroke. The compression ratio rating is 24.0:1.
The Z602-E4B diesel engine produced 15.8 PS (11.6 KW; 15.6 HP) at 3,600 rpm of net (intermittent) horsepower and 17.0 PS (12.5 KW; 16.8 HP) at 3,600 rpm of gross (intermittent) and 37.8 Nm (3.86 kg·m; 27.9 ft·lb) at 2,600 rpm of torque.
The breakdown of the engine code is as follows:
- Z – 2-cylinders
- 60 – Approximate displacement 600 cc
- 2 – Super-Mini series
- E4B – EPA/CARB Tier 4 (NRTC/NTE test mode) + EU Stage V
General information
| Engine Specifications | |
| Engine code | Z602-E4B |
| Layout | Straight-2, vertical diesel engine |
| Fuel type | Diesel fuel No.2-D |
| Production | – |
| Displacement | 0.6 L, 599 cm3 (36.5 cu in) |
| Max. Horsepower |
Net (continuous): 13.7 PS (10.1 KW; 13.5 HP) at 3,600 rpm Net (intermittent): 15.8 PS (11.6 KW; 15.6 HP) at 3,600 rpm Gross (intermittent): 17.0 PS (12.5 KW; 16.8 HP) at 3,600 rpm |
| Torque output | 37.8 Nm (3.86 kg·m; 27.9 ft·lb) at 2,600 rpm |
| Injection type | Indirect injection |
| Cooling system | Liquid-cooled |
| Fuel injection pump | Bosch MD type mini fuel injection pump |
| Fuel nozzle | Bosch throttle type |
| Starting system | Electric starting with 12V (1.0 kW) starter |
| Starting support device | Glow plug in combustion chamber |
| Governor | Centrifugal ball mechanical governor |
| Power adder | None |
| Firing order | 1-2 |
| Dimensions (L x W x H): | 385 x 421 x 544 mm (15.16 x 16.57 x 21.42 in) |
| Weight | 57.0 kg (125.7 lbs) |
Cylinder block
| Cylinder block | ||
| Compression ratio: | 24.0:1 | |
| Cylinder bore: | 72.0 mm (2.83 in) | |
| Piston stroke: | 73.6 mm (2.9 in) | |
| Number of piston rings (compression / oil): | 2 / 1 | |
| Cylinder inner diameter: | 72.000-72.019 mm (2.8346-2.8354 in) | |
| Piston skirt diameter | – | |
| Piston ring side clearance: | Second | 0.090-0.120 mm (0.0035-0.0047 in) |
| Oil | 0.040-0.080 mm (0.0016-0.0031 in) | |
| Piston ring end gap: | Top | 0.200-0.350 mm (0.0079-0.0138 in) |
| Second | 0.350-0.500 mm (0.0138-0.0197 in) | |
| Oil | 0.200-0.350 mm (0.0079-0.0138 in) | |
| Piston pin outer diameter | 20.002-20.011 mm (0.7875-0.7878 in) | |
| Crankshaft main journal diameter: | 43.934-43.950 mm (1.72969-1.73032 in) | |
| Crankpin diameter: | 33.959-33.975 mm (1.337-1.3376 in) | |
Cylinder head
| Cylinder head | ||
| Valve Arrangement: | OHV, gear drive | |
| Valves: | 4 (2 valves per cylinder) | |
| Valve timing: | INTAKE | – |
| EXHAUST | – | |
| Valve seat width: | INTAKE | 2.120 mm (0.0835 in) |
| EXHAUST | 2.120 mm (0.0835 in) | |
| Valve stem diameter: | INTAKE | 5.968-5.980 mm (0.2349-0.2354 in) |
| EXHAUST | 5.968-5.980 mm (0.2349-0.2354 in) | |
| Valve spring free length: | INTAKE | 31.6 mm (1.2441 in) |
| EXHAUST | 31.6 mm (1.2441 in) | |
| Camshaft lobe height: | INTAKE | 26.88 mm (1.0583 in) |
| EXHAUST | 26.88 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) |
Maintenance data
| Valve clearance | |
| Intake valve | 0.145-0.185 mm (0.0057-0.0073 in) |
| Exhaust valve | 0.145-0.185 mm (0.0057-0.0073 in) |
| Compression pressure | |
| Standard | 36.0-41.0 kgf/cm2 (3.53-4.02 MPa, 512-583 psi) |
| Oil system | |
| Recommended engine oil | CD or CE |
| SAE Viscosity Number | SAE 10W-30, 10W-40 |
| Engine oil capacity | 2.5 L (2.6 US. qt, 2.21 Imp. qt.) |
| Fuel system | |
| Injection timing: | 19° B.T.D.C. |
| Fuel injection pressure | 13.73-14.71 MPa (140-150 kgf/cm2, 1991-2133 psi) |
| Cooling system | |
| Coolant capacity: | 2.8 liters (3.0 US.qts, 2.5 Imp. qts) |
| 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) |
| Electrical system | |
| Battery: | 12V, 36Ah or equivalent |
| Alternator (no-load voltage): | AC 20V at 5,200 rpm |
| Glow plug resistance: | Approx 0.9 Ω |
| 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) |
Do you have any estimates of fuel consumption per hour for the Z602 motor running at 3600 rpm