The MWM AKD 112 Z is an air-cooled two-cylinder inline diesel engine produced by MWM from 1955 – 1960.[1] One, three and four cylinder variants of the same engine family were also produced by MWM.
| MWM AKD 112 Z | |
|---|---|
 | |
| Overview | |
| Manufacturer | Motorenwerke Mannheim |
| Production | 1955–1960 |
| Layout | |
| Configuration | Straight-2 |
| Displacement | 1810 cm³ |
| Cylinder bore | 98 mm |
| Piston stroke | 120 mm |
| Valvetrain | OHV |
| Combustion | |
| Operating principle | Diesel |
| Fuel system | Direct injection |
| Fuel type | Diesel oil 45< CN, (Petroleum, Gas oil, Kerosine, Paraffin) |
| Cooling system | Air-cooled |
| Output | |
| Power output | 16.2 kW at 2000 min−1 (DIN 70020) |
| Specific power | 9 kW·dm−3 |
| Torque output | 89.2 Nm at 1500 min−1 |
| Chronology | |
| Predecessor | MWM AKD 12 Z |
| Successor | None |
Description edit
The AKD 112 Z is an air-cooled, two-cylinder, four stroke diesel engine with overhead valves. The letter Z means Zweizylinder, German for two cylinders.
The crankcase is a single cast piece, the drop-forged crankshaft with screwed on counter weights is supported in bearings made of steel-lead-bronze. The crank and shaft pins of the crankshaft are heat-hardened. Due to the air-cooling of the engine, the cylinders have cooling fins made of centrifugal cast metal. The combustion chamber of the engine is a part of the piston bowls, as the engine is direct-injected. The pistons are made of a special highly heat resistant light metal alloy, they have three piston rings and one oil control ring. The bigger conrod eyes are made of steel-lead-bronze, the upper smaller conrod eyes are made of special-bronze. The camshaft is supported by rolling bearings. The overhead valves are actuated by rockers and pushrods. The cylinder head is a single piece made of a chill cast, highly heat resistant light metal alloy. The engine's air filter is a wire-gauze type air filter. For dusty environments MWM offered an oilbath air filter. The air intake must not draw in hot air; this would reduce the engine's power output. The engine has a Bosch injection pump. It is controlled by a centrifugal control mechanism using a pushrod. The control trap makes it possible to change the injection time at the engine start-up to pump more fuel into the cylinder. A forced feed (wet sump) lubrication system lubricates the engine, powered by a gear oil pump. The oil is filtered by a strainer in the low pressure circuit, and a fine sieve strainer in the high pressure circuit. A gap filter in the high pressure circuit was also available. Being air-cooled, the AKD 112 Z has an axial cooling fan powered by the crankshaft using a belt. The power can be taken off the flywheel or the PTO-shaft. An electric motor can be used to start the engine, but a crank starting is standard. The AKD 112 Z has a decompression starting aid system. Being direct-injected, it does not have glowplugs.
| AKD 112 Z | |
|---|---|
| Production period | 1955 – 1960 |
| Engine configuration | Straight two-cylinder four-stroke diesel engine |
| Valvetrain | Overhead valves, actuated by pushrods and rocker arms |
| Bore × Stroke, Displacement |
98 × 120 mm 1810 cm³ |
| Maximum power output at 2000 min−1 | 24 PS (17.7 kW) |
| Rated power output at 2000 min−1 | 22 PS (16.2 kW) |
| Maximum torque at 1500 min−1 | 9.1 kp⋅m (89.2 N⋅m) |
| Specific fuel consumption at highest torque | 251.2 g/kWh ±10 % |
References edit
Bibliography edit
- Betriebsanleitung für den luftgekühlten Klein-Dieselmotor AKD 112 Ein und Zweizylinder. MWM Motoren-Werke Mannheim AG. Vorm. Benz Abt. Stat. Motorenbau. June 1955 (German); Service manual for the air-cooled small diesel engine AKD 112 one and two-cylinders. MWM Motoren-Werke Mannheim AG. Formerly Benz Department for stationary engine development