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Figure 11. Engine cooling system: 1. Pump inlet pipe; 2. Coolant drain hose from the intake pipe to the carburetor heater; 3. Cylinder head outlet pipe; 4. Liquid supply pipe to the interior heater radiator; 5. Hose for draining liquid from the carburetor heater and intake pipe; 6. Thermostat; 7. Expansion tank. 8. Expansion tank cap; 9. Radiator drain hose; 10. Hose from the expansion tank to the radiator; 11. Radiator supply hose; 12. Coolant temperature sensor; 13. Cylinder head; 14. Electric motor; 15. Electric fan casing; 16. Left radiator tank; 17. Electric fan impeller; 18. Radiator; 19. Expansion tank plug valve body; 20. Plug release valve; 21. Inlet valve plug; 22. Radiator cooling pipes; 23. Radiator cooling fins; 24. Electric fan on/off sensor; 25. Right radiator tank; 26. Radiator drain plug; 27. Coolant pump; 28. Timing belt of the gas distribution mechanism; 29. Oil seal thrust ring; 30. Pump body; 31. Locking screw; 32. Pump shaft bearing; 33. Pump toothed pulley; 34. Pump shaft; 35 Seal; 36. Pump impeller; 37. Liquid supply pipe from the interior heater radiator; 38. Solid heat-sensitive filler; 39. Rubber insert; 40. Working element piston; 41. Inlet pipe (from the engine); 42. Thermostat housing; 43. Thermostat cover; 44. Inlet pipe (from the radiator); 45. Thermostat pipe connected to the expansion tank; 46. Main thermostat valve; 47. Thermostat branch pipe for supplying liquid to the pump; 48. Thermostat bypass valve; 49. Holder; I. Coolant temperature gauge sensor; II. Expansion tank cap; III. Coolant pump; IV. Thermostat operation diagram; A. Liquid temperature is above 102°C; B. Liquid temperature from 87°C to 102°C; C. Liquid temperature below 87°C.
The cooling system is a closed-type liquid with forced circulation of liquid, with an expansion tank 7. The system has a coolant pump 27, a non-separable thermostat 6, an electric fan, a radiator 18 with an expansion tank 7, pipelines, hoses, drain plugs. The pump is driven by a toothed belt 28 of the camshaft drive. The capacity of the system, including the interior heater, is 7.8 liters.
To control the temperature of the liquid, there is a sensor 12, which is wrapped in the cooling jacket of the cylinder head. The liquid temperature indicator is installed on the instrument cluster.
When the engine is running, the liquid heated in the cooling jacket of the block and cylinder head enters through the outlet pipe 3 through the hose 11 into the radiator for cooling or into the thermostat 6, depending on the position of the thermostat valves. Then the coolant is sucked in by the pump 27 and sent to the engine cooling jacket. Hoses 2 and 5 provide circulation of the liquid and heating of the combustible mixture in the intake pipe and heating of the throttle zone of the first chamber of the carburetor. The radiator of the car interior heater is connected to the cooling system through pipes 4 and 37 with hoses.
Coolant pump 27 is of the centrifugal type. Pump housing 30 is made of aluminum alloy, shaft 34 is installed in a double-row ball bearing 32, which is locked in the housing with screw 31. To prevent the screw from loosening, the contours of the locking screw seat are peened after assembly. The bearing does not have an internal race, the pump shaft acts as a race. During assembly, the bearing is filled with Litol-24 grease and is not lubricated further. Toothed pulley 33 is pressed onto the front end of the shaft, and impeller 36 is pressed onto the rear end. The toothed pulley is made of a metal-ceramic composition.
The thrust sealing ring 29 of the gland 35, made of graphite composite, is pressed to the end face of the impeller, hardened by high-frequency currents, to a depth of 2-3 mm. The gland is non-separable, pressed into the pump body and prevents leakage of coolant.
Radiator 18 is a detachable tubular-plate radiator with plastic tanks 16 and 25. The radiator core consists of aluminum tubes 22 and aluminum cooling plates 23, is attached to plastic tanks and sealed with rubber gaskets.
The radiator does not have a filler neck, the upper branch pipe of the tank 16 is connected by a hose 10 to the expansion tank. The left tank 16 also has inlet and outlet pipes for connecting hoses 11 and 9. The right tank 25 of the radiator has a drain plug 26 and a sensor 24 for turning on and off the electric fan.
The expansion tank 7 is made of translucent plastic and is secured with a belt to the brackets of the left mudguard of the body. The lower branch pipe of the expansion tank is connected with a hose to the thermostat. To prevent the formation of steam locks, the upper branch pipe of the tank is connected with a hose 10 to the radiator branch pipe. The tank has a filler neck closed with a plastic plug 8 with an outlet (steam) 20 and an inlet 21 valve. The valves in the plug are installed in a separate non-separable housing 19. The opening pressure of the outlet valve is 1.1 kgf/cm², and of the inlet valve is 0.03-0.13 kgf/cm².
To completely drain the fluid from the system, the drain plugs from the radiator tank and from the cylinder block must be unscrewed, and plug 8 of the expansion tank must also be removed.
The electric fan consists of an electric motor 14 and an impeller 17. The impeller has four blades and is made of plastic. The impeller blades have a variable angle of installation along the radius and a variable pitch along the hub to reduce noise. The impeller is mounted on the shaft of the electric motor and is tightened with a nut. For better efficiency, the electric fan is located in a casing 15, which is attached to the radiator brackets at four points.
The electric fan assembly is installed in rubber bushings and secured with nuts on the casing studs. The electric fan is switched on and off depending on the coolant temperature by sensor 24 of the TM-108 type, screwed into the radiator tank on the right side. The sensor contact closing temperature is 99±3°C, opening temperature is 94±3°C.
The cooling system thermostat accelerates engine warm-up and maintains the required thermal conditions. At the optimal thermal conditions, the coolant temperature should be 85-95°C.
Thermostat 6 consists of a housing 42 and a cover 43, which are rolled together with the seat of the main valve 46. The thermostat has an inlet pipe 44 for the cooled liquid from the radiator, an inlet pipe 41 for the liquid bypass hose from the cylinder head to the thermostat, a pipe 47 for supplying coolant to the pump and a pipe 45 for the expansion tank hose.
The main valve 46 is pressed into a cup in which a rubber insert 39 is rolled. In the rubber insert there is a polished steel piston 40, fixed on a fixed holder 49. Between the walls of the cup and the rubber insert there is a heat-sensitive solid filler 38. The main valve is pressed against the seat by a spring. Two posts are attached to the main valve, on which the bypass valve 48 is installed, pressed by a spring.
The thermostat, depending on the temperature of the coolant, automatically turns on or off the radiator of the cooling system, passing the liquid through the radiator, or bypassing it.