KamAZ trucks began to be built in 1969. For a new generation of trucks, engineers created a 4-stroke diesel eight - cylinder KamAZ-740 V8 engine. This power unit had a working volume of 10852 cm3, and its power was 210 horsepower. Then, the power indicators had to be expanded from 180 hp. up to 360. These trucks were equipped with pneumatic clutch, 5-speed gearbox with synchronizers.
The device of the diesel unit
The design of these engines, when compared with others running on diesel fuel, has some advantages. The unit has a relatively small size, and also has a lower mass in comparison with the same YaMZ 238.
Torque from the motor to the main components is transmitted through spur gears. So, the gears of the gas distribution system, pumps and compressors, as well as the hydraulic booster work on the gears.
This engine (KamAZ 740) has a good start even at very low ambient temperatures. This was made possible thanks to the power of the battery, starter and heater units before starting.
Engine Specifications
The model of power plants was named - KamAZ 740 diesel. The cylinders are arranged in a V-shape. The crankshaft rotates to the right. The cylinders have a size of 120 mm, a depth of 120 mm. KamAZ 740 engine with a displacement of 10.85 liters. It has a high compression ratio of 17. The power in the passport in kW is from 154 to 210. The maximum torque is 650 kgf / m. The minimum fuel consumption is 165 liters, the maximum - 178 liters. On each cylinder there is one inlet valve and, accordingly, one exhaust valve.
Consider the KamAZ 740 engine, the device of various components and systems.
Cylinder block
This assembly is nothing more than a part of the unit body. It is intended for mounting and securing all mechanisms and basic systems. The cylinder block is made in the form of a monolithic cast structure. The part has technological holes, as well as channels for lubrication and cooling.
In the upper part of this block there are nests for sleeves. The case is also equipped with channels and cavities for the passage of coolant. The lower part of the cylinder block also serves as a crankcase. The crankshaft is also installed here. The sump has two lubrication holes. Inside the node has partitions with special stiffeners. In these partitions and crankcase walls, special bores are made, which are closed by covers. These parts serve as supports for the crankshaft.
The block is equipped with supports for the camshaft; cam followers are also located here .
Sleeves serve as guides for pistons. Together with the block head, they form a special cavity, which is a fuel combustion chamber. Sleeves are made of special cast iron, and are also quenched by electricity.
The upper part of the plane is represented by cylinder heads. Each of them with its own head. These parts are made of aluminum. Each head inside has a cooling jacket, which in turn is connected to the jacket of the unit. Each head also has lubrication holes, valves for intake and exhaust, a special socket for the nozzle.
The design and operation of the lubrication system
The KamAZ 740 engine is equipped with a combined type lubrication system. Depending on where the rubbing parts are located and under what conditions, oil is supplied in various ways. The system can spray, supply oil at low pressure, or let it flow by gravity.
The device delivers pressurized oil to parts that are more susceptible to wear and work in particularly loaded assemblies. This unit consists of the main devices and devices in which the lubricant is stored, filtration and supply devices, as well as oil cooling.
The oil passes from the sump to the oil receiver, passes through a special filter in the form of a grid. Then it goes to the oil pump. From the discharge section, through a special channel, lubricant is supplied to the oil filter, and then to the mains. Further, lubrication of the cylinder head and cylinder block passes through the lubricating channels under pressure, and then to other components, such as the crankshaft, gas distribution mechanism, compressor, and fuel pump.
In the cylinders, excess grease is removed using oil scraper rings, and then goes further through the piston grooves. This lubricates the piston pin support in the upper head.
From the main line, oil is supplied to the thermosilic sensor. If a valve is open that includes a fluid coupling, then the coupling is also processed. If it is in the closed position, then liquid is supplied from the centrifugal filters to the pan.
If there is insufficient lubrication, the power drops, and the parts also suffer increased wear, the motor overheats, the bearings melt, and the pistons can jam.
KAMAZ 740 engine power system
Our review does not end there. We examined the KamAZ 740 engine itself, the device and the lubrication system. Now let's get acquainted with the power scheme.
The power supply units are designed to store fuel, clean it, and then spray it into the combustion chambers in accordance with the operating mode of the power unit.
The KamAZ 740 engine is equipped with a separation type power unit. Here are divided the fuel injection pump and the nozzle. The system consists of tanks for storing diesel fuel, fuel filters, low pressure pumps, high pressure fuel pumps, as well as fuel pipelines.
How it works?
From the fuel tanks, fuel is pumped to the cleaning filters through a booster pump. Then, through a network of low-pressure fuel products, diesel fuel is fed to the high-pressure fuel pump. After the high-pressure fuel pump injects diesel under high pressure in portions, based on the operating modes of the engine, through nozzles into cylinders and combustion chambers. Nozzles, in turn, spray the mixture. Excess diesel fuel enters the tank again by the bypass valve.
Engine cooling system KAMAZ 740
Cooling is presented as a closed system with a liquid cooler and forced circulation.
In principle, the operation scheme of this system is no different from the usual for all brands of cars. If there is a KamAZ 740 engine diagram, then there you can see in more detail.
The coolant circulates under the influence of a centrifugal pump. First, antifreeze enters the cavity of the left row of cylinders, then through the tube into the right cavity. Then the mixture washes cylinder liners, and then through the holes - the cylinder head cavity.
Then the hot cooler enters the thermostats, and then either to the radiator or to the water pump. Temperature conditions are regulated by thermostats and fluid couplings.
Main engine malfunctions
Among the owners of this car, the main malfunctions of KamAZ 740 engines are considered to be a sharp decrease and power surges, an increase in the consumption of lubricants and fuel. Also a popular malfunction is a high smoke exhaust. Not uncommon and a drop in pressure in the lubrication system.
The unit can unstable idle, sometimes there are different extraneous sounds in different nodes. The main faults are related to the crankshaft. Coolant may leak.
If the unit was used to the limit, and more often - if the KamAZ 740 engine did not have proper maintenance, repair is inevitable. But after a major overhaul, the machine will be able to work again at full strength, and perhaps even much better.
About pricing
Today, such an assembly can still be purchased. The price for the KamAZ 740 engine will be, depending on the configuration and power, from 550,000 rubles per model with a capacity of 240 liters. from. up to 600,000 rubles for a model with a capacity of 320 liters. from. Of course, you can buy much cheaper. The market for used engines currently offers a lot of options at lower prices.
So, we found out all the features of the KAMAZ engine.