The YaMZ-236M2 and YaMZ-238M2 engines are six- and eight-cylinder models of the family of four-stroke diesel engines of OAO Avtodiesel
The YaMZ-238AM2 engine is a modification of the YaMZ-238M2 engine, the power of which is limited to 225 hp. for the entire period of operation.
The YaMZ-238VM engine has the same rated power and maximum torque as the YaMZ-238M2 engine, it differs in its completeness and a special oil pan, allowing operation at increased lists and trims.
Figure 1 shows a general view of the diesel engine
The YaMZ-238GM2 engine is designed for stationary or cyclically variable operating mode and differs from the YaMZ-238M2 engine mainly in its completeness and fuel adjustment equipment.
Figure 2 shows a longitudinal section of the diesel engine
The YaMZ-238KM2 engine is designed for installation on an underground dump truck road train.
Figure 3 shows a cross section of the diesel engine
YaMZ-236M2, YaMZ-238M2, YaMZ-238AM2, YaMZ-238VM, YaMZ-238GM2 and YMZ-238KM2 are interchangeable with YMZ-236M, YMZ-238M, YMZ-238AM, YMZ-238VM, YMZ-238GM and YMZ-238KM engines produced before 1988, as well as with YMZ-236, YMZ-238, YMZ-238A, YMZ-238V, YMZ-238G and YMZ-238K engines produced before August 1985.
Lubrication system
Mixed. The main and connecting rod bearings of the crankshaft, camshaft bearings, connecting rod upper head bushings, valve rocker arm bushings, oil pump intermediate gear bushing, spherical rod bearings, and tappet bushings are lubricated under pressure.
The high-pressure fuel pump and speed controller are equipped with circulating lubrication from the engine lubrication system.
The oil pump is a gear pump, two-section.
The gears, rolling bearings, and camshaft cams are lubricated by splashing.
The pressure in the oil system, kPa (kgf/cm²) for all engines:
- - at nominal speed – 400-700 (4-7)
- - at minimum idle speed, not less than 100 (1.0)
Oil cooling system - oil radiator installed outside the engine
Oil filters
Two - full-flow, with replaceable filter element and fine cleaning - centrifugal, with jet drive. It is allowed to install a coarse filter instead of a full-flow filter.
Opening pressure of the lubrication system valves, kPa (kgf/cm²):
- - pressure reducing valve of the oil pump 700-800 (7.0-8.0)
- - safety valve of the radiator section of the oil pump 100-130 (1.0-1.3)
- - differential valve 520-560 (5.2-5.6)
- - bypass valve of the coarse oil filter 180-230 (1.8-2.3)
- - bypass valve of the full-flow oil filter 200-250 (2.0-2.5)
TECHNICAL CHARACTERISTICS
Lubrication system
Mixed. The main and connecting rod bearings of the crankshaft, camshaft bearings, connecting rod upper head bushings, valve rocker arm bushings, oil pump intermediate gear bushing, spherical rod bearings, and tappet bushings are lubricated under pressure.
The high-pressure fuel pump and speed controller are equipped with circulating lubrication from the engine lubrication system
Oil pump - gear th, two-section
Gears, rolling bearings and camshaft cams are splash lubricated.
Oil system pressure, kPa (kgf/cm²) for all engines:
- - at nominal speed – 400-700 (4-7)
- - at minimum idle speed, not less than 100 (1.0)
Oil cooling system - oil radiator installed outside the engine
Oil filters
Two - full-flow, with replaceable filter element and fine cleaning - centrifugal, with jet drive.
It is allowed to install a coarse filter instead of a full-flow one.
Pressure opening of lubrication system valves, kPa (kgf/cm²):
- - oil pump pressure reducing valve 700-800 (7.0-8.0)
- - oil pump radiator section safety valve 100-130 (1.0-1.3)
- - differential valve 520-560 (5.2-5.6)
- - coarse oil filter bypass valve 180-230 (1.8-2.3)
- - full-flow oil filter bypass valve 200-250 (2.0-2.5)
Fuel supply system
Fuel supply equipment - Separate type
Fuel priming pump - Piston, with manual fuel priming pump
The high-pressure fuel pump of the YaMZ-236M2 engine is a six-plunger one.
The high-pressure fuel pump of the YaMZ-238M2, YaMZ-238AM2, YaMZ-238VM, YaMZ-238GM2, YaMZ-238KM2 engines is an eight-plunger one.
Plungers - Spool type, diameter 10 mm, stroke 11 mm
The operating order of the fuel pump section of the YaMZ-236M2 engine: 1-4-2-5-3-6
The operating order of the fuel pump section of the YaMZ-238M2, YaMZ-238AM2, YaMZ-238VM, YaMZ-238GM2, YMZ–238KM2: 1-3-6-2-4-5-7-8
Section numbering - from the drive side
Speed regulator - centrifugal, all-mode
Injection advance setting angle, degrees:
- - for YMZ–236M2, YMZ–238M2, YMZ–238AM2, YMZ–238VM, YMZ–238GM2 engines - 15°;
- - for YMZ–238KM2 engine - 10°
Advance clutch - automatic. centrifugal type
Injectors - closed type, with multi-tier sprayers
Injection start pressure, MPa (kgf/cm²) - 22.6+0.8 (230+8)
Fuel filters
Two, coarse and fine with replaceable filter elements.
A bypass jet is installed in the fine filter cover
Air filter - inertial-oil or dry type
Cooling system
Liquid, closed type, with forced circulation of coolant; equipped with a thermostat to maintain a constant thermal operating mode of the engine
Water pump - centrifugal, driven by a V-belt from the crankshaft pulley
Fan - six-bladed, with a gear drive
Electrical equipment
Generator - three-phase synchronous, alternating current, with a built-in rectifier unit
Generator - on engines YaMZ-236M2, YaMZ-238M2, YaMZ-238AM2, YaMZ-238VM, YaMZ-238GM2 - G-273V2 or 1322.3771
Generator of the YaMZ-238KM2 engine - 1702.3771
Nominal rectified voltage, V - 28
Starter - 25.3708-01, direct current, series excitation, with electromagnetic drive
Starter rated power, kW, at C20=182Ah - 8.2
Clutch
Model for engine:
- - YaMZ–236M2 - YaMZ-236K or YaMZ-181*;
- - YaMZ–238M2 - YaMZ-238 or YaMZ-182*;
- - YaMZ–238AM2, YaMZ–238VM, YaMZ–238GM2, YaMZ–238KM2 - YaMZ-238
Gearbox gears
Model:
- - for engine YaMZ-236M2 - YaMZ-236P;
- - for engines YaMZ-238M2, YaMZ-238AM2, YaMZ-238VM, YaMZ-238GM2, YaMZ-238KM2 - YaMZ-236N
Type - Mechanical, three-way, five-speed, with synchronizers on second-third and fourth-fifth gears
Gear ratios:
- - first gear - 5.26
- - second gear - 2.90
- - third gear - 1.52
- - fourth gear- 1.00
- - fifth gear - 0.66
- - reverse - 5.48
Weight of the engine without fuel, kg:
Filling capacities, l
Cylinder numbering scheme
