What is the Principle of Crankcase Ventilation?
2 Answers
Crankcase ventilation principle: During engine operation, high-pressure combustible mixture and burned gases from the combustion chamber may leak into the crankcase through the gap between the piston assembly and the cylinder to varying degrees, causing blow-by. The blow-by consists of unburned fuel vapor, water vapor, exhaust gases, etc., which degrade the performance of the engine oil. To prevent excessive crankcase pressure and extend the service life of the engine oil, crankcase ventilation is essential. Crankcase ventilation includes natural ventilation and forced ventilation. Modern gasoline engines commonly use forced crankcase ventilation, also known as the PCV system. Natural ventilation involves installing a ventilation pipe on the crankcase, equipped with an air filter screen. When the pressure inside the crankcase increases, the gases leaking into the crankcase are expelled through the ventilation pipe.
I've been thinking about crankcase ventilation for quite a while. Simply put, when the engine is running, gases from the combustion chamber may leak into the crankcase through the piston rings. These gases include oil vapors and harmful substances. If they accumulate there, the oil will become dirty, leading to engine problems. The ventilation system is designed to expel these gases, usually through a tube connected to the intake system, with a PCV valve controlling the airflow. This allows the exhaust gases to be drawn back into the engine and burned. This approach is both environmentally friendly, reducing air pollution, and extends the life of the engine oil. I must remind everyone that if the ventilation tube is blocked, the car may shake or emit white smoke. During regular maintenance, it's best to check if the PCV valve is stuck or worn out. Maintenance is quite simple, and you can even learn to replace it yourself, but beginners shouldn't disassemble it randomly to avoid damaging other components.
