Where is the return pipe for crankcase ventilation? Before or after the throttle? It is best to talk about the circulation process of crankcase ventilation, thank you.

The return pipe for crankcase ventilation must be connected to the intake pipe behind the throttle.

During the engine operation, a small amount of high temperature and high pressure gas will escape into the crankcase from the gap between the piston and the cylinder. The crankcase is difficult to dissipate heat and the environment is harsh. Therefore, the ventilation pipe is used to connect the intake pipe and the crankcase. When the engine is working, the waste in the crankcase is pumped out by the vacuum generated by the intake pipe and enters the secondary combustion. The crankcase ventilation pipe has a one-way switch, which only allows airflow from the crankcase to the intake pipe.

The above is the crankcase ventilation process. Its main function is to remove the exhaust gas in the crankcase, improve the working environment of the crankcase, assist the heat dissipation of the crankcase and reduce the exhaust pollution.