1. Excessive oil temperature is harmful to the engine
The so-called engine temperature is too high means that the engine oil temperature and water temperature exceed 90°C. When these two temperatures are too high at the same time, it will affect the normal operation of the engine and cause certain harm to the engine. If the water temperature is too high, the combustion conditions will deteriorate, high-temperature parts will undergo thermal expansion, and the gap between the piston and the cylinder wall will shrink, causing severe wear or “cylinder pull”. The oil temperature mainly indicates that the crankshaft and bearings generate heat due to friction, and the engine oil dissipates most of the heat. The balance between heat production and heat dissipation (shown as stable oil temperature) is relative. Therefore, when the temperatures of oil and water are too high at the same time, the oil temperature should be lowered first.
2. Lowering the oil temperature can slow down the rate of increase in water temperature
The method of “reducing load and lowering speed” is usually used to reduce oil temperature. At this time, although the coolant takes a long time to exchange heat at the high-temperature parts, the water flow rate slows down, prolonging the heat dissipation time. At the same time, due to the reduction in load and rotation speed, the heat generated by the friction of each moving part is also reduced accordingly. Therefore, lowering the oil temperature can not only reduce the heat generated by the engine, but also indirectly reduce the heat absorbed by the coolant, which can also slow down the increase in water temperature.
3. Oil temperature is one of the main factors affecting oil pressure
When the engine oil temperature is too high, it will not only increase fuel consumption (leakage, evaporation, combustion), but also affect the quality of the engine oil, making it difficult for the oil film on the friction surfaces of the engine parts to form and maintain, causing the main oil passage oil pressure to be unable to be established. , thereby aggravating the wear of machine parts. The influence of water temperature on oil pressure must be realized through oil temperature. Therefore, it has a certain degree of indirection and requires a certain amount of time.
4. Lowering the water temperature first has a great influence on the establishment of oil pressure in the engine main shaft oil passage
As we all know, the method of “reducing load and increasing speed” is generally used to reduce water temperature. When the rotational speed is too high, the inertial force and centrifugal force of the piston linkage group will be increased, which will increase the load on the crankshaft bearing. At the same time, the relative friction speed between the journal and the bearing bush will also increase, causing the heat generated per unit time to increase, the amount of oil in the oil pump to decrease, and a large amount of oil to be thrown out from the main oil passage, resulting in the friction surface of each machine part being lost. Enough lubricating oil will aggravate wear and the oil temperature will further rise.
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Post time: Apr-25-2024