Mitsubishi L2C Specifications
| Engine Model: Mitsubishi L2C |
| Engine Type: 4-cycle 2-cylinder naturally aspirated liquid-cooled diesel |
| Total Displacement: 32.8 cu.in (0.54 L) |
| Rated Engine Power: 12 Hp (9 kW) at 3600 rpm |
| Fuel System Type: Indirect injection |
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The Mitsubishi L2C is a compact, 2-cylinder,
4-stroke liquid-cooled diesel engine belonging to the Mitsubishi
L-Series family. Mitsubishi positions this engine line as the smallest
and lightest water-cooled diesel engines produced globally, with a 10 to
20 percent weight reduction and a 15 to 20 percent smaller contour
volume compared to competitor engines of the same class.
The Mitsubishi L2C is a naturally aspirated unit employing an indirect
injection swirl chamber combustion system, which prioritizes smooth
operation and low noise over peak power output. With a displacement of
538 cc and a square bore and stroke of 70 mm x 70 mm, this engine
produces approximately 9.5 to 12 hp depending on the application and
rating.
The L2C is engineered for high-speed continuous operation up to 3,600
rpm, making it suitable for replacing gasoline engines in applications
such as rice harvesters, mini-tractors, lawn mowers, generators,
welders, and marine installations. The engine features a pressure-fed
lubrication system with a full-flow oil filter and a gear-type oil pump
driven directly by the crankshaft. Its robust cast iron construction and
replaceable components contribute to a service life exceeding 500
operating hours under normal agricultural conditions.
The Mitsubishi L2C is an inline, 4-cycle, water-cooled, naturally
aspirated diesel engine. The engine features two cylinders arranged in a
straight configuration. Total displacement measures 538 cubic
centimeters, equivalent to 0.538 liters or 32.8 cubic inches. The bore
is 70 mm (2.76 in) with a stroke of 70 mm (2.76 in), producing a
perfectly square design that balances torque production and engine speed
capability. The combustion system is indirect injection using a swirl
chamber type design, where fuel is injected into a pre-chamber before
entering the main combustion chamber.
The compression ratio is not specified in the available documentation
but is characteristic of indirect injection diesel engines. The firing
order for a 2-cylinder engine is 1-2. Maximum power output is 9.5 to 12
hp (7.1 to 9.0 kW) depending on the governed speed and application.
Rated engine speed for continuous operation is 3,600 rpm. Idling speed
is set between 750 and 800 rpm. The dry weight of the L2C engine is not
individually listed, but the L-Series engines as a class are noted for
being the lightest water-cooled diesels in their power category.
The cylinder block is constructed from cast iron with an inline
2-cylinder configuration. The block is designed to be compact and
lightweight, with integrated mounting points for agricultural and
industrial equipment. The water jacket surrounds each cylinder bore for
efficient heat transfer. The crankshaft is supported by three main
bearings (one at each end and one between the two cylinders).
The cylinder bores are machined directly into the block; the L2C uses a
parent bore design rather than replaceable liners. The oil pan mounts to
the bottom of the block and is sealed with a gasket or liquid sealant.
The timing gear case is integrated into the front of the cylinder block,
housing the gear train that drives the camshaft and injection pump. The
block includes a side-mounted oil filter housing and provisions for
mounting the starter motor and generator.
The cylinder head is a single cast iron unit covering both cylinders.
The valvetrain is an overhead valve (OHV) design with two valves per
cylinder, yielding a total of four valves. Each cylinder has one intake
valve and one exhaust valve. The camshaft is located in the cylinder
block and operates the valves via pushrods and rocker arms. Valve lash
adjustment is performed manually with the engine cold.
Intake and exhaust valves share the same clearance specification: 0.25
mm (0.0098 in) measured at the valve stem tip with the engine at ambient
temperature. The combustion chamber is of the swirl chamber type
(indirect injection). A separate pre-chamber cast into the cylinder head
creates a swirling motion of air during the compression stroke.
This design reduces combustion noise and allows the use of a lower
compression ratio compared to direct injection engines. The cylinder
head contains the glow plugs, one per cylinder, which preheat the
combustion chamber for cold starting. The intake ports are designed to
generate swirl, while the exhaust ports are separate to reduce
interference. The cylinder head gasket is a composite or steel design
selected for the specific engine application.
The fuel system is an indirect injection diesel system with a mechanical
injection pump. A gear-type supply pump draws fuel from the tank and
delivers it to the injection pump. The injection pump is a mechanical
inline or distributor type, driven by the engine's gear train. The pump
delivers fuel at high pressure to the injection nozzles, which are of
the pintle type designed for indirect injection systems. Each cylinder
has a dedicated injection nozzle mounted in the cylinder head, spraying
fuel into the swirl chamber.
Fuel injection pressure is regulated by the pump's internal governor.
The governor is a mechanical flyweight type that maintains engine speed
under varying loads. A hand-operated primer pump is located on the fuel
filter housing or injection pump to bleed air from the system. The fuel
filter is a cartridge or spin-on type with water separation capability.
The system operates with diesel fuel meeting local specifications, with
a minimum cetane number of 45 recommended for reliable cold starting.
The lubrication system is a pressure-feed, full-flow filtering design. A
gear-type oil pump, comprising inner and outer gears in mesh, is
enclosed within the timing gear case and driven directly by the
crankshaft. The pump draws oil from the sump through a screened pickup
tube and forces it through a full-flow paper-element cartridge type oil
filter. The oil filter contains a relief valve that opens at a
differential pressure of 0.10 ± 0.02 MPa (14.2 ± 2.9 psi) to bypass the
filter element if it becomes restricted.
The oil pump includes a pressure relief valve that opens at 0.30 ± 0.03
MPa (42.7 ± 4.3 psi). The oil capacity, excluding the filter, ranges
from 1.4 liters (lower limit) to 2.4 liters (upper limit), equivalent to
0.37 to 0.63 U.S. gallons. The oil filter adds an additional 0.5 liters
(0.13 U.S. gallons) to the total system capacity. Operating oil pressure
is maintained by the relief valve. A separate pressure switch
illuminates a warning lamp when pressure drops below 0.05 ± 0.01 MPa
(7.1 ± 1.4 psi).
The cooling system is a pressurized, thermostatically controlled liquid
cooling design. A belt-driven centrifugal water pump circulates coolant
through the cylinder block and cylinder head. Coolant enters the block
at the front and flows rearward through the water jacket surrounding the
cylinder bores. Coolant rises through passages in the cylinder head
gasket into the head, where it circulates around the combustion
chambers, valve seats, and injector nozzles before exiting through the
thermostat housing.
A wax-pellet thermostat with a nominal opening temperature of 70 to 80°C
(158 to 176°F) controls coolant flow to the radiator. A bypass circuit
allows coolant to circulate within the engine without passing through
the radiator until operating temperature is achieved. A radiator with an
engine-driven fan provides heat rejection.
A pressure-type radiator cap, rated at 0.5 to 1.0 bar (7 to 15 psi),
maintains system pressure to raise the coolant boiling point. The system
requires a 40 to 50 percent mixture of ethylene glycol antifreeze with
distilled water for freeze protection and corrosion inhibition of the
cast iron components.
| Intake and Exhaust Systems |
Intake System: A dry-type or oil-bath air cleaner, depending on the
application, filters incoming air. A rubber hose connects the air
cleaner to the intake manifold. An optional intake air heater may be
fitted for cold starting in low ambient temperatures.
Exhaust System: A cast iron exhaust manifold collects exhaust gases from
both cylinders and directs them to a single outlet for connection to a
muffler and exhaust pipe.
Electrical System: 12-volt system with a negative ground. The alternator
is rated at 15 to 40 amperes depending on equipment. The starter motor
is a pre-engaged type rated at approximately 1.0 to 1.5 kW. Glow plugs
are pencil-type with a heating element; the glow controller manages
pre-heat duration based on coolant temperature or ambient conditions.
Timing System: The camshaft and fuel injection pump are driven by a gear
train at the front of the engine. A gear on the crankshaft drives an
idler gear, which drives the camshaft gear and the injection pump gear.
This all-gear system requires no periodic replacement.
Overall length, measured from the front timing gear cover to the
flywheel housing mating surface, is 450 mm (17.7 in). Overall width,
measured across the widest point including the injection pump and intake
manifold, is 400 mm (15.7 in). Overall height, measured from the bottom
of the oil pan to the top of the cylinder head, is 550 mm (21.7 in). The
dry weight of the complete engine, inclusive of the starter motor,
alternator, injection pump, and flywheel, is 50 kg (110 lb). The long
block assembly weighs 35 kg (77 lb).
Regular maintenance is required for L2C longevity. The engine oil and
filter must be changed after the first 50 hours of operation for a new
engine. Subsequent oil changes are required every 100 operating hours or
once per year, whichever occurs first. The oil filter must be replaced
every 200 hours. Recommended oil viscosity is SAE 10W-30 for all-season
use in most climates, meeting API classification CD or higher.
Valve clearance inspection and adjustment is required every 200 hours.
Intake valve clearance (cold engine, not running) is 0.25 mm (0.0098
in). Exhaust valve clearance (cold) is also 0.25 mm (0.0098 in). The
fuel filter requires replacement every 200 hours. The air cleaner
element requires cleaning or replacement according to the restriction
indicator or at every oil change in dusty conditions.
The engine coolant requires replacement every 1,000 hours or 24 months.
The injection timing is set at the factory and does not require routine
adjustment. The glow plugs should be tested annually; resistance should
measure 0.5 to 1.5 ohms per plug. The drive belt for the water pump and
alternator requires inspection at every oil change for cracking or
glazing, with replacement at 500 hours.
Cylinder Head Bolts (M10): 73.5 to 83.4 Nm (54.3 to 61.5 lb-ft).
Cylinder Head Bolts (M8): 19.6 to 29.4 Nm (14.5 to 21.7 lb-ft).
Connecting Rod Cap Bolts: 48.8 to 54.2 Nm (36.0 to 40.0 lb-ft).
Main Bearing Cap Bolts: 48.8 to 54.2 Nm (36.0 to 40.0 lb-ft).
Flywheel Bolts: 48.8 to 54.2 Nm (36.0 to 40.0 lb-ft).
Intake and Exhaust Manifold Nuts (M8): 14.7 to 21.6 Nm (10.9 to 15.9
lb-ft).
Rocker Arm Shaft Bracket Bolts: 19.6 to 29.4 Nm (14.5 to 21.7 lb-ft).
Injection Nozzle Hold-Down Bolts: 24.5 to 34.3 Nm (18.1 to 25.3 lb-ft).
Glow Plugs: 14.7 to 19.6 Nm (10.9 to 14.5 lb-ft).
Water Pump Mounting Bolts: 14.7 to 21.6 Nm (10.9 to 15.9 lb-ft).
Oil Pan Bolts: 9.8 to 14.7 Nm (7.2 to 10.9 lb-ft).
Timing Gear Cover Bolts: 9.8 to 14.7 Nm (7.2 to 10.9 lb-ft).
Engine Mount Bracket Bolts: 29.4 to 39.2 Nm (21.7 to 28.9 lb-ft).
The Mitsubishi L2C engine is deployed across a range of compact
agricultural, industrial, and marine equipment, primarily in Asian and
European markets.
Agricultural Equipment (Application Code 11): Rice combine harvesters
(Japanese market), rice planters, mini-tractors (under 20 hp),
walk-behind tractors, and small cultivation equipment.
Industrial Equipment (Application Code 31): Generators (portable and
stationary), welders (engine-driven welding machines), small pumps,
compressors, and sweepers.
Marine Applications: Small auxiliary engines for sailboats and small
fishing vessels. The L2C is also rebranded as the Vetus M2.C5 and M2.D5
marine diesel engines.
Lawn and Garden Equipment: Zero-turn mowers, commercial lawn mowers, and
turf maintenance equipment where diesel power replaces gasoline engines.
Export Applications (Application Code 61): Complete equipment for export
markets, including micro-excavators, mini-loaders, and compact
construction equipment.
Replacement Engines: The L2C is used as a replacement power unit for
Casalini vehicles (Ydea, Sulky Ydea, Sulky Car, Kerry) and Airman
equipment (DCR6FSSII).
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