Selection of lubricant
The selection of a suitable viscosity and excellent quality lubricant is of great significance to the normal operation of the internal combustion engine and to extend its service life. Therefore, the basic principles for selecting lubrication are:
(1) Select according to load and speed.
Those with large load and low speed, such as some large diesel engines, should use lubricants with high viscosity; while those with low load and high speed, such as gasoline engines, should use low viscosity lubricants.
(2) Choose according to region, season and temperature.
In cold winter areas, such as the northeast and northwest, lubricating oils with low viscosity and low freezing point should be selected; the temperature throughout the year is relatively high, such as the Jiangnan region, lubricating oil with slightly higher viscosity should be used.
(3) Select according to the wear status of the internal combustion engine.
The oil with a higher viscosity is suitable for a long service life and a large part wear. The new internal combustion engine can choose a lubricant with a lower viscosity.
(4) Specially used lubricating oil should be used for internal combustion engines equipped with superchargers.
1) According to the instructions of the internal combustion engine operating instructions, select the specified brand of lubrication.
2) Clean the lubricant. When filling the lubricating oil, ensure that the fueling port and fueling vessels are clean to prevent the invasion of dust and sand; maintain the lubricating oil filter on time; maintain the air filter and fuel filter on time to prevent impurities from entering the crankcase from the cylinder.
3) Lubricant temperature. The normal working temperature of lubricating oil is 45 ~ 90 ℃. After the internal combustion engine is started, it should be warmed up, and when the standby oil temperature is higher than 45 ° C, it should be put into operation or running. When the ambient temperature is high and the working time is long, when the temperature of the lubricating oil is higher than 90 ° C, it should run at idle speed and work after the temperature drops.
4) Prevent water from entering the lubricant. Prevent water or rain from entering the lubricant when refueling. When the crankcase oil level is found to increase during the operation, the cause should be analyzed in time, and the working conditions of the pump water seal, cylinder block, cylinder head and other components should be checked to troubleshoot.
5) Prevent fuel from being mixed with lubricant. Maintain the normal working temperature of the cooling system. The normal water temperature of water-cooled internal combustion engines is 80 ~ 95 ℃, and the temperature of the cylinder head of air-cooled internal combustion engines should be less than 120 ℃. If the temperature is too high, the oxidative deterioration of the lubricant will be accelerated; if it is too low, a part of the mixture entering the cylinder will condense into a liquid and flow into the crankcase. Maintain the good working condition of the fuel system, timely check and adjust the fuel supply advance angle and injection atomization quality of the high-pressure pump and injector to avoid fuel atomization and poor vaporization, and flow into the lubricant oil along the cylinder wall.
6) Prevent the pollution of lubricating oil by exhaust gas. Install the piston ring correctly; the clearance between the piston and the cylinder liner, the clearance between the valve and the duct should be appropriate; keep the crankcase well ventilated and sealed clean.
7) Lubricant replacement timing. Before starting each internal combustion engine, check the quantity and quality of the lubricating oil, and consider replacing it when one of the following conditions occurs: when the oil dipstick is drawn out, the lubricating oil on the dipstick quickly flows away, or the lubricating oil is dripped on the paper and quickly diffuses. It means that the lubricating oil is too thin; if you twist the lubricating oil with your fingers, you will feel that there is no smooth oil film with blackness and fuel smell; there are too many metal chips in the lubricating oil. The replacement of the lubrication is generally after the new car or the overhauled machinery has completed the trial operation; every 600 hours of diesel engine operation and 400 hours of gasoline engine operation (approximately 14,000 km); in the winter or summer, to overcome the problem, only refueling without oil replacement, and oil replacement for oil replacement Bad phenomenon.
8) The lubrication system is cleaned. Clean the lubrication system when changing the lubricant. The method is to discharge the old lubricating oil of the lubricating system while hot, add the mixed oil of clean lubricating oil and diesel oil (4: 1) to the underline of the dipstick, stop the engine after the engine idling for 3 to 5 minutes, and fill with new lubricating oil. To the specified oil level.