Adjustment of YaMZ-236 valves. Diesel engine for heavy vehicles

In the product line YaMZ many power units. One of them is YaMZ-236. They are staffed with a huge number of very different construction and road machinery. This engine is installed on MAZ, "Ural", diesel generators, as well as some models of buses. YaMZ-236 is a development of 55 years ago, but today there is practically no alternative, as well as its peers in terms of characteristics. Naturally, reliable operation of the engine requires regular maintenance. Let's consider features of this motor and we will find out, how adjustment of valves JAMZ-236 is carried out.

Universal and competitive

Probably the only enterprise in Russia that can produce competitive diesel power units for trucks, as well as for construction equipment, is the Yaroslavl Motor Plant.

Any engine from the line represents brutality, reliability, unpretentiousness in service and simplicity. And most often these motors show excellent opportunities for integration into the technology of the new century.

How to create the motor

In the 1950s, the Yaroslavl Plant received a special order from the state to develop and further launch production of powerful diesel power units, which were supposed to replace the already outdated YaAZ for that period. These engines were to become not only more powerful, but also more economical than the YaAZ. In the USSR, they wanted to get a universal diesel internal combustion engine, which could be installed on a wide variety of cars.

Engineers worked under the well-known talented designer Chernyshev G.D. Under his sensitive guidance, not only the 236th engine was created, but also other mechanisms from this family. So the engine was born, which to this day there are no equal. It is installed on the "Ural". The car from this very much won in the technical characteristics. It is also the best motor for tractor and construction machinery.

YaMZ-236: production now

Now JSC "Avtodizel" still produces this unit, but also collects its successor - it YaMZ-530.

Sales of engines do not fall, although now they are not supplied to Ukraine. But production is growing steadily.

Device and specifications

The engine has six cylinders, which are arranged in two rows at right angles. Such a V-shaped arrangement is used to reduce the dimensions of the unit and its weight. This is also done to reduce the weight of the car as a whole. One of the main differences between these motors from all others is the rational placement of each unit. All this is perfectly combined with the high simplicity of the design. There is good accessibility to each node for maintenance or repair. Motor parts require regular maintenance. In particular, the adjustment of the YaMZ-236 valves must be performed every 40,000 kilometers. All those elements that require regular service are in the front of the engine, as well as between the cylinders.

On the front part there is a fuel filter, a compressor for the brake system and an electric generator. These elements are attached to the top cover of the unit. Both the compressor and the generator use a belt as a drive. Left on the front of the unit are oil filters - coarse and fine cleaning. The starter is located on the right side. The crankcase is securely protected by a pallet. By the way, the pallet simultaneously plays the role of a container for oil. On the adjacent planes of each row of cylinders are the cylinder heads. There you can find the valves of the gas distribution system and diesel injectors. The valve mechanism is hidden under steel covers. In one of them there is a branch pipe - oil is poured through it.

Engine Block

Block YMZ-236 is made of low-alloyed gray cast iron. Casting is then processed using artificial aging technology. This is done in order to remove thermal stresses and keep the exact geometry in the process of operation. The cylinder liner has thick walls. They are centered on two bores in the bottom and top of the block. The right row of combustion chambers is slightly offset from the left by 35 cm. This is necessary for placing the connecting rods.

Cylinder Head

The head of the base motor from JSC "Avtodizel" is an integral casting of cast iron. It is fixed to the block with special pins. The latter are made of chromium-nickel alloy steel and have been heat treated. To remove heat during operation of the motor, the head is equipped with a jacket for the coolant and the rest of the unit. Inside the cylinder head there are pressurized valves. They are equipped with spring and fasteners. In the same place there are nozzles and rocker arms. Saddle-valve plug-in, made of special heat-resistant cast-iron alloys. It is pressed into the socket. Between the head and the unit is installed a single for every three cylinders a sandwich pad.

Timing mechanism

The gas distributing mechanism on the YaMZ-236 is an upper valve. The camshaft is located at the bottom. The valve is activated by means of a system of pushers, rocker arms and rods. The camshaft is made by the method of forging from carbon steel 45. The pushers are also steel, made by punching technology. Valves, both inlet and outlet, are made of heat-resistant steels. Periodically, a diesel engine requires maintenance. Need to adjust the valves YaMZ-236 and some other standard operations.

How to adjust the valves?

This timing mechanism must have a thermal gap. This is done to seal the valve seat in its seat, and also compensate for thermal expansion. The dimensions of the clearance in the exhaust and inlet valves must be equal to each other. This parameter is from 0.25 to 0.3 millimeters. If the engine is operated long enough, then the clearance can be increased to 0.4 millimeters. The YAMZ-236 valves are adjusted only on a cold motor. The process is as follows. First turn off the fuel supply. Then unscrew the nuts holding the cylinder head cover. The lid is removed and the tightening torque of the bolts on the rocker arms is checked with a torque wrench . Then the crankshaft is turned clockwise. Then observe the movement of the intake valve on the first cylinder and wait for it to close.

After that, the crankshaft is rotated for another four turns. Then, using a feeler gauge, check the clearance. If necessary, the parameter is corrected by turning the lock nut on the rocker adjusting screw. The bolt is fixed with a screwdriver. The procedure for adjusting the YAMZ-236 valves differs in no way from the same procedure for other engine models. After the process is over, it is necessary to check the condition of the gaskets and, if necessary, replace them.

Modern YaMZ-236

Cast iron as a base material at the plant was used until 2010. But later engineers and designers decided that it's time to use aluminum. Now the block and the head of the block are made of this metal, which greatly simplified the repair of YaMZ-236, the boring of the necks of the combustion chambers. Also, the honing procedure became much more accurate. At the same time, the block did not lose its strength. At YaMZ-236 the price in this form is 460 thousand rubles. On the secondary market, you can buy copies for 50-200 thousand rubles. Everything depends on the state.

Specifications

The engine has an impressive working volume of 11 liters. Power can vary from 150 to 420 horsepower, depending on the type and availability of turbocharging. In the latest versions and versions, the parameter can be increased to 500 forces. Since the cost of fuel is constantly growing, the manufacturer has managed to reduce fuel consumption. So, if the "Urals" (car) consumed before 40 liters per 100 kilometers of the road, now the motor spends only 25 liters. At the same time, the truck did not lose traction characteristics.

So, we found out the features of the power unit from the Yaroslavl Motor Plant.