DEVICE AND OPERATION OF ENGINES YaMZ-238BE2, YaMZ-238BE, YaMZ-238B, YaMZ-238DE2, YaMZ-238DE, YaMZ-238D

YaMZ 238 engine: specifications

"Long-liver" with an impeccable reputation

Few of the diesel engines can boast such a solid "track record" as the YaMZ-238. This engine has become the "heart" of many thousands of MAZ, KrAZ, Ural trucks familiar to everyone and everyone; tractors "Kirovets" and "ChTZ"; combines "Don" and "Polesie". As well as a large number of all kinds of highly specialized equipment, boats, diesel power plants. YaMZ-238 is extremely reliable and unpretentious in operation, which provided him with a “long-liver career”: the engine launched into series in the early 60s continues to roll off the assembly line of the Yaroslavl Motor Plant today. Despite the fact that a lot of more modern "successors" appeared in the assortment of the plant.

About the history of the plant and the YaMZ-238 predecessor engines

Yaroslavl Automobile Plant. So until 1958 this enterprise was called, which produced trucks, buses and trolleybuses. In many things, YaAZ became a pioneer. Here, in the 1920s, the production of the first heavy-duty vehicles (from 3 to 7 tons) in the Land of Soviets was launched. In the 1930s, the first dump trucks in the USSR left the assembly line of the plant; single and double-decker buses and trolleybuses.

The first diesel engine in the Union was also produced in Yaroslavl. Here, by the end of the 1930s, Russian-made MD-23 diesel engines for trucks and tractors were tested and prepared for mass production. But the mass production of diesel engines was established only two years after the end of the Great Patriotic War. During the war years, YaAZ gave the front light tracked tractors for artillery.

Since 1947, the plant has launched serial production of families of 2-stroke four- and six-cylinder diesel engines YaAZ-204 and YaAZ-206 with power from 110 to 220 hp. First of all, the developers of new families of motors, YaMZ-236 and YaMZ-238, relied on the experience of their production and operation.

50s of the twentieth century. Workshop of the Yaroslavl Automobile Plant. In the photo - a 10-ton dump truck YaAZ-210

During 1958-1961, a group of scientists led by the outstanding Soviet designer and inventor Georgy Dmitrievich Chernyshev created and prepared for the launch in a series the best diesel engines in the world at that time: powerful, versatile, reliable and trouble-free. And also economical (for that time). For the development of these four-stroke six- (YaMZ-236) and eight-cylinder (YaMZ-238) engines with power from 180 to 500 hp. was awarded the State Prize of the USSR, and the plant was awarded the Order of Lenin.

In our time, YaMZ has retained the function of a full-cycle enterprise: with its foundry, forging press, thermal, welding, galvanic, painting, hardware, mechanical assembly, assembly and testing, tool, repair production. With energy facilities, transport and storage services, a developed network of sales and service points, with workshops for small machine tool building and non-standard equipment. YaMZ is part of the GAZ Group holding.

Description of the model YaMZ-238D and B (238D, 238B)

Number of cylinders: 8 Bore, mm: 130 Stroke, mm: 140 Cylinder displacement, l: 14.86 Rated power, kW (hp): 243 (330) Crankshaft speed at rated power, min: 2100 Maximum torque, N m (kgf m): 1225 (125) Crankshaft speed at maximum torque, min -1, no more: 1200-1400 Crankshaft speed
at idle, min -1 minimum: 550-650 maximum: 550-650

Mixing method: Direct injection Fuel supply equipment: Divided High-pressure fuel pump: Eight-plunger Fuel priming pump: Piston type with a manual pumping pump Speed regulator: Centrifugal all-mode with boost control Nozzles : Closed type with multi-hole atomizer Turbocharger: Radial centripetal turbine; centrifugal compressor Lubrication system: Mixed, pressure and splash Oil filters: Two: full-flow with replaceable paper element and centrifugal oil filter Cooling system: Liquid, closed type, with forced circulation of the coolant. Equipped with a thermostatic device Starting device: Starter 25.3708-01 direct current, sequential excitation with electromagnetic drive. Rated power 8.1 kW (11 hp), voltage 24 V. Device to facilitate start-up: Electric torch device Generator: Three-phase, synchronous, alternating current with electromagnetic excitation G273V1 or 1322.3771. For installation on KrAZ vehicles - generator 1702.3771 Clutch: YaMZ-238N - Double-disc, dry, friction type, with a peripheral arrangement of pressure coil springs. YaMZ-183 - Single-disk, diaphragm type.

Transmission: Mechanical, three-way, eight-speed, dual-range. Installed: 1. For MAZ vehicles - YaMZ-238A gearbox, or - YaMZ-238M4 gearbox; or - YaMZ-238VM4 gearbox - manufactured by TMZ, differs from the YaMZ-238M4 gearbox by the design of the demultiplier switching mechanism There is a rod support between the cylinder and the demultiplier crankcase The coordinate of the demultiplier signal lamp switch has been changed; 2. For KrAZ vehicles - YaMZ-238B gearbox; or - the YaMZ-238K4 gearbox - differs from the YaMZ-238M4 gearbox by the presence of a gear lever installed instead of the top cover plug; or - YaMZ-238VK4 gearbox - manufactured by TMZ; 3. For UralAZ vehicles - the YaMZ-238U gearbox - differs from the YaMZ-238M4 gearbox only in the absence of a flange on the output shaft cover for fastening the speedometer drive unit, or - the YaMZ-238VU gearbox - manufactured by TMZ.

Weight of the unfilled engine in the scope of delivery (with clutch and gearbox), kg: 1130 (1580)

Number of cylinders: 8 Bore, mm: 130 Stroke, mm: 140 Cylinder displacement, l: 14.86 Rated power, kW (hp): 220 (300) Crankshaft speed at rated power, min: 2000 Maximum torque, Nm (kgfm): 1180 (120) Crankshaft speed at maximum torque, min -1, no more: 1200-1400

The frequency of rotation of the crankshaft at idle, min: - minimum: 550-650 - maximum: 550-650

Weight of the unfilled engine in the scope of delivery (with clutch and gearbox), kg: 1130 (1580)

Source

Technical characteristics of the YaMZ-238 engine

So, YaMZ-238 is a four-stroke eight-cylinder diesel engine with a classic V-shaped cylinder arrangement, direct fuel injection, compression ignition and liquid cooling. Available in both conventional "atmospheric" and turbocharged versions.

Year 2015. In the photo - YaMZ-238 / Euro 2 Turbo engines

In total, at present, the assortment of the plant, set out in the current official price list on the YaMZ website, includes 25 different modifications of the YaMZ-238 engine. A number of turbocharged versions (DE series, for dump trucks and trucks, MAZ, KrAZ, Ural truck tractors; tractors and timber trucks) have been finalized to Euro-2 standards. In total, the general list of modifications of this motor has 86 positions.

Motor modifications

ICE YaMZ 238 received a lot of modifications and applicability in the automotive range. So, according to the manufacturer's technical documentation, let's consider which model range and modifications the G8 engine has:

235 HP (173 kW) at 1700 rpm, 1108 N • m (113 kgf • m) at 1300 rpm - YaMZ-238ND3.
235 HP (173 kW) at 1700 rpm, 1108 N • m (113 kgf • m) at 1300 rpm - YaMZ-238ND6.
240 HP (177 kW) at 2100 rpm, 882 N * m (90 kgf * m) at 1500 rpm - YaMZ-238 (base).
250 HP (184 kW) at 1900 rpm, 1108 N • m (113 kgf • m) at 1300 rpm - YaMZ-238ND4.
250 HP (184 kW) at 1900 rpm, 1108 N • m (113 kgf • m) at 1300 rpm - YaMZ-238ND7.
280 HP (206 kW) at 2100 rpm, 1029 N • m (105 kgf • m) at 1500 rpm - YaMZ-238PM.
290 HP (184 kW) at 2000 rpm, 1128 N • m (115 kgf • m) at 1400 rpm - YaMZ-238DK.
300 HP (220 kW) at 1900 rpm, 1280 N • m (131 kgf • m) at 1300 rpm - YaMZ-238ND5.
300 HP (220 kW) at 1900 rpm, 1280 N•m (131 kgf•m) at 1300 rpm — YaMZ-238ND8.
320 HP (235 kW) at 2100 rpm, 1117 N • m (114 kgf • m) at 1500 rpm - YaMZ-238FM.
330 HP (243 kW) at 2000 rpm, 1225 N • m (125 kgf • m) at 1400 rpm - YaMZ-238DK.
330 HP (243 kW) at 2100 rpm, 1225 N • m (125 kgf • m) at 1300 rpm - YaMZ-238D.
330 HP (243 kW) at 2100 rpm, 1225 N • m (125 kgf • m) at 1300 rpm - YaMZ-238DE.
330 HP (243 kW) at 2100 rpm, 1274 N • m (130 kgf • m) at 1200 rpm - YaMZ-238DE2.
330 HP (243 kW) at 1900 rpm, 1274 N • m (130 kgf • m) at 1200 rpm - YaMZ-6582.
360 HP (265 kW) at 1900 rpm, 1570 N • m (160 kgf • m) at 1200 rpm - YaMZ-7512.
400 HP (294 kW) at 1900 rpm, 1715 N • m (175 kgf • m) at 1200 rpm - YaMZ-7511.
400 HP (294 kW) at 1900 rpm, 1764 N • m (180 kgf • m) at 1200 rpm - YaMZ-6581.
420 HP (309 kW) at 1900 rpm, 1764 N • m (180 kgf • m) at 1200 rpm - YaMZ-7513.

Owner reviews about YaMZ-238. Comparison with KamAZ-740

If we summarize the reviews of the owners of equipment with YaMZ-238, then we can confidently call this motor the best in the YaMZ-236 - YaMZ-238 - YaMZ-240 line. It takes into account all the shortcomings of YaMZ-236; and there is enough power just enough to work in difficult conditions, such as long-haul or quarry transportation.

In favor of the YaMZ-238, the fact that they showed themselves excellently on KamAZ trucks also speaks. And when selling used KamAZ trucks, the fact that they have the YaMZ-238 engine (“from MAZ”) is presented as a big plus. Since in the “battle” of close competitors - YaMZ-238 and KamAZ-740, the Yaroslavl engine has an indisputable victory, both in conventional and turbocharged versions. YaMZ-238 provides confident traction at both low and high speeds. Kama engine requires higher revs. In terms of fuel and oil consumption, Yaroslavl is more economical. It is also more convenient to maintain it - all units have excellent access and space, while KamAZ-740 has a denser layout.

These are extremely precisely adjusted power units specifically for heavy equipment. At the same time, they leave the opportunity to do without an excessive supply of power, and, accordingly, without busting in terms of efficiency. By the way, there is a 12-cylinder YaMZ-240 family for solving super-heavy and super-complex tasks.

It is worth mentioning such components of the long-term popularity of the YaMZ-238 as simplicity and maintainability, the absence of problems with spare parts and, of course, an extremely attractive price compared to imported counterparts (even Chinese ones).

Engine repair: basic description

Repair of the YaMZ 238 engine is a whole range of operations to restore the engine's performance, which is not recommended to be done by hand. So, it is worth contacting professionals who can correctly diagnose malfunctions and wear, as well as which internal element needs to be replaced. Consider the main set of operations that is carried out for the YaMZ 238 motor in order to overhaul the motor:

Superficial fault diagnosis is carried out by ear. The minder determines the presence of extraneous noise, as well as the preliminary location.
Dismantling the motor from the car, as well as carrying out a complete disassembly of the power unit.
Measurements of cylinders and crankshaft. Determining the repair number, as well as ordering spare parts. As practice shows, in most cases, in order not to bore the engine cylinders, the block is sleeved. This parameter allows, and in the case of subsequent repairs, to bore not the block, but the sleeves, which, when worn, can be removed and new ones inserted.
Cylinder head repair.
Assembly of the power unit.

A separate parameter is the restoration of the injection pump. As practice shows, the master repairs only the plunger pair, which wears out most often.

As for in-line repair operations, each owner of a car with a YaMZ engine has sufficient skills and knowledge to restore his engine on his own, the main thing is that the hand grows from the right place. The most common problems include:

Starter and alternator failure.
Failure of the water pump.
Replacing drive belts.
Valve mechanism adjustment.
Change of oil.
Replacing engine filters.

Repair instructions for each node are available on the Internet or you can use factory books that are publicly available.