Alpha Marine Propulsion Engines
Variable Speed
1500 – 3000 r/min
6.8 – 37.5 kw | 9.7 – 50.3 bhp
Range
20
22
30
33
40
43
50 Turbo
Download the Engine Data Sheet
The Alpha marine propulsion engine is specifically designed to suit for small offshore boats, work boats, pleasure craft and hire fleets. It is durable, reliable and easy to maintain with oil and filter changes up to 500 hours, dependent on operational conditions.
It is designed for continuous operation in ambient temperature up to 52°C (122°F) and cold start capability down to -32°C
(-25.6°F).
Basic Engine Characteristics
- 2, 3 or 4 cylinders
- raw water heat-exchanger cooling
- direct fuel injection
- naturally aspirated and turbocharged
- 4 cylinder
- low fuel consumption
- long service periods
Standard Equipment
- heat exchanger
- water cooled exhaust manifold
- fuel filter / agglomerator
- self-vent fuel system with fuel lift pump
- individual fuel injection pump for each cylinder
- high level oil filler and dipstick
- raw water cooling system pump
- operators' handbook (English)
- thermostatically controlled cooling system with belt driven raw water pump
- gear driven positive displacement type lubricating oil pump
- spin on full flow lubricating oil filter
- mechanical governing
- gearbox adaptor and drive plate to suit PRM150 or PRM280 (LPWT4) gearboxes
- cooling water header tank at gear end
- 12V 70 Amp insulated earth return alternator and 12V 2.0 kW starter motor with earthing solenoid as standard
- SAE5 flywheel housing
- oil pressure and coolant temperature switches and VDO gauge senders
- fuel control solenoid (energised to stop)
- skid base packing
Options Items
A range of options enables are available that allows you to select a specification that matches your requirements.
- keel cooling fittings
- earth return electrics
- 24V electrics
- range of gearboxes (PRM, ZF or Techno Drive)
- choice of air cleaners
- high level bearers (wide or narrow options)
- choice of engine control panels
- range of gearbox mounting adaptors, and drive couplings
- high output alternator
- cooling water header tank mounted at flywheel end (not 50 Turbo)
- anti-vibration mountings
- sump lubricating oil drain pump (gear end or flywheel end mounting)
- paint colour (standard is Peacock Blue)
Full Engine Specifications:
Power Output
| 20-LPW2 | 22-LPWX2 | 30-LPW3 | 33-LPWX3 | 40-LPW4 | 43-LPWX4 | 50-LPWXT4 | ||
|---|---|---|---|---|---|---|---|---|
| 1500* | 1500* | 1500* | 1500* | 1500* | 1500* | 1500* | ||
| Continuous Power | kWm | 6.8 | 7.9 | 10.3 | 11.9 | 13.6 | 15.8 | 18.9 |
| bhp | 9.1 | 10.6 | 13.8 | 15.9 | 18.2 | 21.2 | 25.3 | |
| Fuel Stop | kWm | 7.5 | 8.8 | 11.8 | 13.2 | 15.0 | 17.6 | 20.9 |
| bhp | 10.0 | 11.8 | 15.8 | 17.7 | 20.1 | 23.6 | 28.1 | |
Torque
| 20-LPW2 | 22-LPWX2 | 30-LPW3 | 33-LPWX3 | 40-LPW4 | 43-LPWX4 | 50-LPWXT4 | ||
|---|---|---|---|---|---|---|---|---|
| r/min | 2000 | 1800 | 2000 | 1800 | 2000 | 1800 | 1800 | |
| Nm | 51 | 58 | 76 | 87 | 102 | 86 | 151 | |
Fuel Consumption
| 20 | 22 | 30 | 33 | 40 | 43 | 50 Turbo | ||
|---|---|---|---|---|---|---|---|---|
| Load | 1500* | 1500* | 1500* | 1500* | 1500* | 1500* | 1500* | |
| g/kWh | 224 | 245 | 261 | 261 | 253 | 271 | 209 | |
| l/h | 2.0 | 2.3 | 3.2 | 3.7 | 4.1 | 5.1 | 3.7 | |
Technical Data
| 20 | 30 | 40 | 50 Turbo | 22 | 33 | 43 | ||
|---|---|---|---|---|---|---|---|---|
| Type of fuel injection | Direct | Direct | Direct | Direct | Direct | Direct | Direct | |
| Number of cylinders | 2 | 3 | 4 | 4 | 2 | 3 | 4 | |
| Aspiration | Natural | Natural | Natural | Turbocharged | Natural | Natural | Natural | |
| Direction of rotation looking on flywheel end | Anti clockwise | Anti clockwise | Anti clockwise | Anti clockwise | Anti clockwise | Anti clockwise | Anti clockwise | |
| Compression ratio | 18.5:1 | 18.5:1 | 18.5:1 | 16.2:1 | 19.5:1 | 19.5:1 | 19.5:1 | |
| Total cylinder capacity | litre | 0.930 | 1.395 | 1.860 | 1.860 | 0.999 | 1.499 | 1.998 |
| in 3 | 56.75 | 85.1 | 113.5 | 113.5 | 60.96 | 91.47 | 121.93 | |
| Nominal cylinder bore | mm | 86.0 | 86.0 | 86.0 | 86.0 | 86.0 | 86.0 | 86.0 |
| in | 3.39 | 3.39 | 3.39 | 3.39 | 3.39 | 3.39 | 3.39 | |
| Firing order | 1-2 | 1-2-3 | 1-3-4-2 | 1-3-4-2 | 1-2 | 1-2-3 | 1-3-4-2 | |
| Off load idling speed | 900 | 900 | 900 | 900 | 900 | 900 | 900 | |
| Number of flywheel ring gear teeth | 96 | 96 | 96 | 96 | 96 | 96 | 96 | |
| Max continuous crankshaft end thrust | kgf | 180 | 180 | 180 | 180 | 180 | 180 | 180 |
| lbf | 400 | 400 | 400 | 400 | 400 | 400 | 400 | |
