Mitsubishi KE75 Specifications
| Engine Model: Mitsubishi KE75 |
| Engine Type: 4-cycle 2-cylinder naturally aspirated liquid-cooled diesel |
| Total Displacement: 46.6 cu.in (0.76 L) |
| Rated Engine Power: 17 Hp (12.7 kW) at 2800 rpm |
| Fuel System Type: Indirect injection |
____________________________________________________________________________________
The Mitsubishi KE75 is a vertical,
water-cooled, 4-stroke, 2-cylinder diesel engine produced by Mitsubishi
Heavy Industries. This engine belongs to the KE series of compact diesel
powerplants and serves as a larger-displacement sibling to the KE70.
Manufactured primarily during the late 1970s and early 1980s, the KE75
found widespread application in vintage Japanese compact tractors from
manufacturers including Mitsubishi, Iseki, Satoh, Bolens, and Case IH.
The engine features a swirl chamber indirect injection combustion
system, a design choice that provides smoother operation and lower
combustion noise compared to direct injection engines of the same era.
The KE75 is renowned for its fuel efficiency, mechanical simplicity, and
ease of maintenance, making it suitable for light agricultural tasks
such as plowing, cultivating, landscaping, and property maintenance. The
robust cast iron construction and conservative power rating of 15-17
horsepower contribute to engine longevity, with many units remaining
operational decades after production ceased in the mid-1980s.
The Mitsubishi KE75 is a 4-stroke, inline 2-cylinder diesel engine
designed for compact utility tractors and light agricultural equipment.
The engine architecture follows a simple inline configuration with a
firing interval of 360 degrees. The bore and stroke are nearly equal,
with a slight oversquare relationship that provides a balanced
combination of low-end torque and governed speed operation.
The engine operates on the swirl chamber (indirect injection) principle,
where fuel is injected into a pre-combustion chamber before combustion
proceeds into the main cylinder. This design permits the use of a lower
compression ratio compared to direct injection engines and results in
quieter operation at governed speeds. The engine is naturally aspirated
with a dry-type air cleaner system.
Engine Type: Inline 2-cylinder, 4-stroke diesel
Displacement: 764 cc (46.6 cu.in)
Bore x Stroke: 78 mm x 80 mm (3.071 in x 3.150 in)
Compression Ratio: 21.0:1 (approximate for indirect injection)
Valvetrain: OHV, 2 valves per cylinder (4 valves total)
Firing Order: 1-2
Fuel System: Swirl chamber (indirect injection)
Cooling System: Water-cooled with centrifugal pump
Rated Engine Speed: 2,600 rpm
Maximum No-Load Speed: 2,700-2,800 rpm
Maximum Power (Tractor Rating): 15-17 hp (11.2-12.7 kW) @ 2,600-2,700
rpm
Maximum Power (Mitsubishi D1500): 15 hp (11.2 kW) @ 2,300 rpm
Maximum Power (Suzue 170): 17 hp (12.7 kW) @ 2,400 rpm
The cylinder block is constructed from high-strength cast iron with a
conventional skirted design. The block features integral cylinder bores
machined directly into the parent cast iron material, a parent-bore
design without replaceable liners. This construction method provides
adequate durability for the engine's conservative power output and
governed operating speeds. The block contains three main bearing
supports to carry the cast nodular iron crankshaft.
The crankcase area is reinforced with ribbing around the main bearing
caps to manage the forces generated during diesel combustion. Cast-in
water jackets surround both cylinder bores for coolant circulation, with
cooling passages directed to the upper cylinder area where combustion
temperatures are highest. The engine features a side-mounted oil filler
and a dipstick tube cast into the block or attached externally. Freeze
plugs are installed in the block sides to protect against coolant
expansion damage in cold climates.
0The cylinder head is manufactured from cast iron, providing durability
and resistance to thermal fatigue under sustained load conditions. The
head utilizes a cross-flow design with the intake and exhaust manifolds
mounted on opposite sides. The swirl chamber is cast into each
cylinder's combustion chamber area, creating the pre-combustion chamber
that characterizes indirect injection diesel engines.
The valve actuation system consists of a camshaft located in the
cylinder block, mechanical lifters, pushrods, and forged steel rocker
arms mounted on a rocker shaft. The valves are arranged in an inline
configuration with intake and exhaust valves positioned parallel to each
other for each cylinder. Valve seats are pressed-in alloy steel rings,
and valve guides are replaceable units pressed into the head casting.
The cylinder head gasket is a composite construction with a steel fire
ring around each cylinder bore.
Valves per Cylinder: 2 (1 intake, 1 exhaust)
Total Valves: 4
Valve Arrangement: Overhead valve (OHV)
Intake Valve Clearance (Cold): 0.25-0.35 mm (0.010-0.014 in)
Exhaust Valve Clearance (Cold): 0.25-0.35 mm (0.010-0.014 in)
Valve Seat Angle: 45 degrees
Camshaft Drive: Gear train
The fuel system employs a swirl chamber indirect injection design
manufactured by Bosch or Zexel under license. An inline injection pump,
mounted on the side of the cylinder block and driven by the engine
timing gear train, delivers fuel to the injection nozzles at precise
timing intervals. Each cylinder has a dedicated injection nozzle
installed in the cylinder head, directing fuel into the swirl chamber.
The injection timing is adjustable by rotating the injection pump
mounting flange or shims.
A mechanical governor, integrated into the injection pump housing,
maintains engine speed under varying loads by adjusting fuel delivery. A
fuel filter with integral water sedimenter is mounted on the engine or
chassis frame. A hand primer lever on the injection pump or lift pump
allows manual fuel system priming after filter changes or after running
out of fuel. The injection nozzle opening pressure is set using shims
beneath the nozzle spring.
Fuel Type: Diesel (standard grade)
Injection System: Swirl chamber (indirect injection)
Injection Pump Type: Inline, mechanical, with integral governor
Injection Timing: 20-22 degrees BTDC
Injection Nozzle Opening Pressure: 110-120 bar (1,595-1,740 psi)
Fuel Lift Pump: Mechanical diaphragm, camshaft-driven
The lubrication system is a full-pressure, forced-feed design. A
gear-type oil pump, mounted on the front of the crankshaft or within the
timing gear cover and driven directly from the crankshaft, draws oil
from the oil pan through a submerged strainer. The pump delivers oil
under pressure to a full-flow spin-on oil filter mounted on the cylinder
block. A bypass valve allows oil flow to the bearings if the filter
becomes restricted. Filtered oil is routed through a main oil gallery
machined into the cylinder block.
Cross-drilled passages direct oil from the gallery to the three main
bearings. Drilled passages in the crankshaft feed oil from each main
bearing to the adjacent connecting rod bearings. Oil is also routed
upward through a vertical passage in the cylinder block and cylinder
head to lubricate the valve train components. An oil pressure relief
valve located near the oil pump outlet maintains system pressure. The
oil pan is constructed from stamped steel with a drain plug at its
lowest point.
Oil Type: Diesel engine oil, SAE 15W-40 or 10W-30 (API CF or higher)
Total Oil Capacity (including filter): 2.6-3.0 L (2.7-3.2 US qt)
Oil Pressure (Operating, warm): 30-50 psi (207-345 kPa)
Oil Pressure (Idle, warm, minimum): 7-10 psi (48-69 kPa)
Oil Filter Type: Spin-on, full-flow
Oil Change Interval: 100-150 operating hours
The cooling system is a pressurized, forced-circulation design. A
centrifugal water pump mounted on the front of the cylinder block and
driven by a V-belt from the crankshaft pulley circulates coolant through
the engine and radiator. Coolant enters the water pump inlet, is
discharged into the cylinder block water jacket, and flows upward around
the cylinder bores and into the cylinder head. The heated coolant then
travels forward through the cylinder head to the thermostat housing
mounted at the front of the head.
A wax-pellet thermostat regulates coolant flow to the radiator,
beginning to open at 76.5 °C (170 °F) and reaching full open at 90 °C
(194 °F). When closed, coolant bypasses the radiator for rapid warm-up;
when open, coolant is directed to the top tank of the radiator, passes
downward through the vertical tube-and-fin core, and returns to the
water pump inlet. A belt-driven fan mounted on the water pump hub draws
air through the radiator core. A coolant recovery tank maintains system
fill level.
Coolant Type: Green ethylene glycol antifreeze with corrosion inhibitors
Total Cooling System Capacity (including radiator): 4.0-5.0 L (4.2-5.3
US qt)
Thermostat Opening Temperature (Start): 76.5 °C (170 °F)
Thermostat Full Open Temperature: 90 °C (194 °F)
Radiator Cap Pressure: 7-10 psi (48-69 kPa)
Water Pump Type: Centrifugal, sealed bearing, belt-driven
| Intake and Exhaust Systems |
Intake System: Air enters through a dry-type paper element air cleaner
mounted on the intake manifold or remotely mounted with a rubber hose
connection. The air cleaner includes a dust cup or evacuator valve to
remove large particles before they reach the paper element. A
restriction indicator may be installed on some applications to signal
when the air cleaner element requires service. The intake manifold is a
cast iron component with a central plenum feeding two runners.
Exhaust System: The exhaust manifold is a single-piece cast iron unit
with two ports merging into a single outlet. The manifold is mounted on
the opposite side of the cylinder head from the intake manifold in the
cross-flow arrangement. The exhaust outlet is positioned at the front or
center of the manifold for connection to the muffler and exhaust pipe. A
exhaust pipe with a rain cap or vertical stack is used on tractor
applications.
The engine is equipped with a 12-volt electrical system with a
belt-driven alternator or DC generator producing 20-35 amperes depending
on the application. A solenoid-operated starter motor is mounted on the
engine block or transmission bellhousing. The system includes a voltage
regulator either external on early models or integrated into the
alternator on later versions. System Voltage: 12V. Starter Motor Power:
0.8-1.0 kW. Alternator Output: 20-35A.
Glow Plug System: Glow plugs are energized by a glow controller or
push-button switch on the tractor dashboard. A glow indicator lamp
signals when the glow plugs have reached operating temperature. Glow
plug operation time ranges from 5 to 15 seconds depending on ambient
temperature.
Cold Start System: Glow plugs installed in the cylinder head swirl
chambers provide pre-heating for cold weather starting. The glow
controller energizes the glow plugs for a duration inversely
proportional to coolant temperature. A grid heater or intake air heater
is not installed. Ether starting aids are not recommended due to
potential combustion knock damage.
The Mitsubishi KE75 is a compact engine designed for installation in
sub-compact and compact tractors. The dimensions reflect the inline
2-cylinder architecture with the fuel injection pump mounted on the side
of the cylinder block.
Overall Length (front of fan to flywheel housing): 550 mm (21.7 in)
Overall Width (across valve cover and injection pump): 500 mm (19.7 in)
Overall Height (crankshaft centerline to top of intake manifold): 650 mm
(25.6 in)
Crankshaft Centerline to Top of Cylinder Head: 300 mm (11.8 in)
Crankshaft Centerline to Bottom of Oil Pan: 200 mm (7.9 in)
Bore Pitch: 95 mm (3.74 in)
Dry Weight (complete assembly, no fluids): 110-125 kg (243-276 lb)
Wet Weight (with all fluids): 120-135 kg (265-298 lb)
Engine Oil Change Interval: 100-150 operating hours or annually
Engine Oil Filter Change Interval: Replace with every oil change
Fuel Filter Change Interval: 200 operating hours or 12 months
Valve Clearance Inspection Interval: 200 operating hours
Intake Valve Clearance (Cold): 0.25-0.35 mm (0.010-0.014 in)
Exhaust Valve Clearance (Cold): 0.25-0.35 mm (0.010-0.014 in)
Injection Timing Check Interval: 500 operating hours
Injection Timing Specification: 20-22 degrees BTDC
Injection Nozzle Inspection Interval: 500 operating hours
Coolant Replacement Interval: 500 operating hours or 2 years
Air Cleaner Element Cleaning/Replacement: 100 operating hours
Glow Plug Inspection Interval: 200 operating hours
Drive Belt Inspection Interval: Inspect every 100 operating hours
Drive Belt Inspection Interval: Replace at 500 hours or as needed
Idle Speed (Warm, No Load): 800-900 rpm
Cylinder Head Bolts (Large M12): 108-118 Nm (79.5-86.8 lb-ft)
Cylinder Head Bolts (Small M10): 69-79 Nm (50.6-57.9 lb-ft)
Main Bearing Cap Bolts: 49-54 Nm (36.2-39.8 lb-ft)
Connecting Rod Cap Nuts: 31-34 Nm (23.1-25.3 lb-ft)
Flywheel Bolts: 58-68 Nm (43-50 lb-ft)
Camshaft Thrust Plate Bolts: 12-15 Nm (9-11 lb-ft)
Rocker Shaft Bracket Bolts: 20-25 Nm (15-18 lb-ft)
Intake Manifold Nuts: 15-20 Nm (11-15 lb-ft)
Exhaust Manifold Nuts: 15-20 Nm (11-15 lb-ft)
Oil Pan Bolts: 10-12 Nm (7-9 lb-ft)
Water Pump Mounting Bolts: 15-20 Nm (11-15 lb-ft)
Injection Pump Mounting Nuts: 15-20 Nm (11-15 lb-ft)
Injection Nozzle Retaining Nut: 50-60 Nm (37-44 lb-ft)
Glow Plugs: 10-15 Nm (7-11 lb-ft)
Starter Motor Mounting Bolts: 25-30 Nm (18-22 lb-ft)
The Mitsubishi KE75 engine is widely used across compact tractor
platforms from multiple manufacturers. Production of vehicles equipped
with this engine occurred primarily between 1973 and 1986. Many of these
tractor models were sold under different brand names in various global
markets, including North America, Europe, Australia, and Japan.
Mitsubishi Tractors:
D1500, D1500D, D1500V (1973-1976): Compact utility tractor; 15 hp @
2,300 rpm; 2-cylinder diesel; 4 forward / 1 reverse transmission; 12 V
electrical system.
MT160, MT160D: Compact tractor variant for North American and European
markets; 16 hp rating.
MT372, MT372D: Sub-compact tractor; KE75 engine.
MT470: Larger frame compact tractor.
Iseki Tractors:
TX1500, TX1500F: Compact utility tractor; 15 hp (11.2 kW) @ 2,600 rpm;
46.6 ci displacement; dry air cleaner; 2.7 qt oil capacity; 3.2 gal fuel
tank.
Iseki KE75 variants: Additional models sold in Japanese domestic market.
Satoh Tractors:
ST1500 (Beaver), ST1510: Compact utility tractor sold in North America;
15 hp (11.2 kW) @ 2,700 rpm; 46.6 ci displacement; 12 V starter.
S470 (Buck): Sub-compact tractor.
Bolens Tractors:
G172, G174: Compact tractors sold in North America; KE75 engine;
manufactured under license from Mitsubishi.
Case IH Tractors:
234 (select variants): Compact utility tractor; KE75 engine.
Suzue Tractors:
170: Compact utility tractor; 17 hp (12.7 kW); 0.8 L displacement; 78 x
80 mm bore/stroke; liquid-cooled 2-cylinder diesel.
____________________________________________________________________________________
| Industrial Engines Technical Specifications |
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Outboard Engines Technical Specifications |
