There are many power units in the YaMZ product line. One of them is YaMZ-236. He is equipped with a huge amount of a wide variety of construction and road equipment. This engine is installed on MAZs, Urals, diesel generators, as well as on some bus models. YaMZ-236 is a development of 55 years ago, but today there is practically no alternative, as well as equal characteristics. Naturally, for reliable operation, the engine needs regular maintenance. We will consider the features of this motor and find out how the YaMZ-236 valves are adjusted.
Versatile and competitive
Probably the only enterprise in Russia that today 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 maintenance and simplicity. And most often, these motors show excellent opportunities for integration into the technology of the new century.
How to create a motor
In the 50s, the Yaroslavl plant received a special order from the state for the development and further launch of the production of powerful diesel power units, which were supposed to replace the already outdated YAZ at that time. 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 variety of cars.
Engineers worked under the guidance of the famous talented designer Chernyshev G.D. Under his strict guidance, not only the 236th motor was created, but also other mechanisms from this family. So the engine was born, which to this day has no equal. It is installed on the Urals. The car greatly benefited from this in technical specifications. It is also the best motor for tractor and construction equipment.
YaMZ-236: production now
Now Avtodizel OJSC still produces this unit, but its successor is also being assembled - this is YaMZ-530.
Sales of engines do not fall, although now they are not delivered 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 was used to reduce the dimensions of the unit and its weight. It is also done to reduce the weight of the car as a whole. One of the main differences between these engines from all others is the rational placement of each unit. All this goes well with the high simplicity of the design. Good accessibility to each unit for maintenance or repair is noted. Motor components require regular maintenance. In particular, the adjustment of the YaMZ-236 valves should be carried out every 40 thousand kilometers. All those elements that require regular service are located in front of the engine, as well as between the cylinders.
On the front of the top is a fuel filter, a compressor for the brake system and an electric generator. These items are attached to the top cover of the unit. Both the compressor and the generator use a belt as a drive. On the left on the front front of the unit are oil filters - coarse and fine cleaning. On the right side below is the starter. The crankcase is protected by a pallet. By the way, the sump at the same time plays the role of an oil tank. On the mating 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 the steel covers. In one of them there is a pipe - oil is poured through it.
Engine block
The YaMZ-236 block is made of low-alloy gray cast iron by casting. The casting is then processed using artificial aging technology. This is done in order to remove thermal stresses and maintain accurate geometry during operation. The cylinder liner has thick walls. They are centered on two bores in the lower and upper part of the block. The right row of combustion chambers is slightly offset from the left by 35 cm. This is necessary to accommodate the connecting rods.
Cylinder head
The head of the base motor from Avtodiesel OJSC is a solid cast iron casting. It is fixed to the block using special studs. The latter are made of chromium-nickel steel alloy and have been heat treated.
To remove heat during the operation of the motor, the head is equipped with a jacket for coolant and the rest of the unit. Inside the cylinder head are the valves pressed into it. They are equipped with spring and fasteners. There are nozzles and rockers. The valve seat is plug-in, made of special heat-resistant cast iron alloys. It is pressed into the socket of a preload. Between the head and the block there is a single sandwich gasket for every three cylinders.
Timing mechanism
The gas distribution mechanism on the YaMZ-236 is an overhead valve. The camshaft is located below. The valve is actuated using a system of pushers, rockers and rods. The camshaft is made by forging of carbon steel 45. Pushers are also steel, made by stamping technology. Valves, both inlet and outlet, are made of heat-resistant steels. Periodically, a diesel engine requires maintenance. Need adjustment valves YaMZ-236 and some other standard operations.
How to adjust the valves?
This timing mechanism must necessarily have a thermal gap.
This is done to seal the valve seat in its seat, as well as compensate for thermal expansion. The size of the gap in the exhaust and intake valve should 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 carried out as follows. First turn off the fuel supply. Then unscrew the nuts holding the cylinder head cover. The cover is removed, using a
torque wrench, check the tightness of the bolts on the rocker axles. Next, the crankshaft is rotated clockwise. Then observe the movement of the intake valve on the first cylinder and wait for it to close.
After that, the crankshaft is cranked another four turns. Then, using a feeler gauge, check the clearance. If necessary, the parameter is adjusted by rotating the lock nut on the rocker adjusting screw. In this case, the bolt is fixed with a screwdriver. The procedure for adjusting the YaMZ-236 valves is no different from the similar procedure on other engine models. After the end of the process, it is necessary to check the condition of the gaskets and replace them if necessary.
Modern YaMZ-236
Cast iron was used as a base material in the plant until 2010. But later, engineers and designers decided that it was time to use aluminum. Now the block and the block head are made of this metal, which greatly simplified the repair of the YaMZ-236, boring the necks of the combustion chambers. Also, the honing procedure has become 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. In the secondary market, you can buy copies for 50-200 thousand rubles. It all depends on the condition.
Specifications
The motor has an impressive displacement of 11 liters. Power can vary from 150 to 420 horsepower, depending on the type and availability of a turbocharger. In the latest modifications and versions, the parameter can be increased up to 500 forces. Since the cost of fuel is constantly growing, the manufacturer was able to reduce fuel consumption. So, if the Urals (car) previously consumed 40 liters per 100 kilometers, now the engine consumes 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.