The YaMZ-238 engine has earned the reputation of being very reliable and unpretentious in operation, thanks to which the engine launched into series in the early 60s continues to be produced at the facilities of the Yaroslavl Motor Plant to this day.
Modern YMZ 238 models comply with all international quality standards and European environmental standards, and its cost is several times lower than that of its foreign competitors with similar technical characteristics. The engine is intended for heavy vehicles “MAZ”, “KrAZ”, “Ural”; tractors “Kirovets” and “ChTZ”; combines “Don” and “Polesie”; other special equipment. It has good fuel economy, efficiency and performance.
|Manufacturer||Public joint-stock company «Autodiesel», Yaroslavl Motor Plant|
|Cylinder block alloy||cast iron|
|Number of cylinders||8|
|Valves per cylinder||2|
|Piston stroke, mm||140|
|Cylinder bore, mm||130|
|Power output, hp||235/1700
|Torque output, Nm / rpm||1108/1300
|Euro standards||Euro 0
|Weight, kg||1075 (YAMZ-238M2)|
|Fuel consumption at speed 60 km/h, L/100 km (for Ural 4320)||38|
|Oil consumption, % to fuel consumption||0.5
0.2 (Euro 2)
|Recommended engine oil:
-winter (less +5° C)
|Engine oil capacity, liter||29 (atmospheric)
|Oil change interval, hours||500
— official information, hours
— real, thousand km
YAMZ-238 cylinder block
The cylinder block is cast from low alloyed gray iron. Serves as the basis for the installation of all parts and assemblies of the engine. V-shaped block with a camber angle of 90º. The right row of cylinders is displaced relative to the left one forward by 35 mm, which is due to the installation of 2 connecting rods on each connecting rod journal of the crankshaft. Each cylinder seat has 2 coaxial cylindrical holes made in the upper and lower plates of the block, along which the cylinder liner is centered, in the upper plate there is an annular groove for the liner collar.
YAMZ-238 cylinder head
The cylinder head is made of low-alloy gray cast iron and is secured to the block with studs screwed into the cylinder block. The studs are made of chromium-nickel steel and heat-treated. To ensure heat dissipation, the cylinder head has a liquid cooling cavity communicating with the block cavity. To provide fuel supply to the nozzle, there are holes for tubes in the side surface of the head. The cylinder head houses valves with springs, rocker arms, rocker arms and injectors.
The crankshaft is made of steel, manufactured by hot stamping. All surfaces of the shaft are nitrided and the depth of the nitrided layer is at least 0.35 mm. The crankshaft has 5 main bearings and 4 connecting rod journals. Connecting rods are installed on the connecting rod journals (2 for each). The main and connecting rod journals are lubricated with oil under pressure during operation. Oil is supplied to the main bearings, and then through the inclined channels to the connecting rod journals. In the connecting rod journals there are internal cavities closed with plugs, where the oil is subjected to additional centrifugal cleaning.