Why doesn't the legendary ga5 have a crankshaft ventilation check valve?

The crankcase ventilation check valve is located on (or near) the valve cover and the connected intake pipe.

When the engine works normally, a part of combustible mixture and exhaust gas will always leak into the crankcase through the gap between the piston, piston ring and cylinder wall. These gases have high temperature and carry fuel molecules and other impurities, and the engine oil will gradually oxidize, deteriorate and dilute at high temperature.

These gases entering the crankcase will increase the pressure in the crankcase and cause oil leakage failures such as gaskets and oil seals, so the gas leaking into the crankcase must be discharged in time. Therefore, in early engines, there was a device called crankcase ventilation device.

Crankcase ventilation check valve has the following functions:

1. Introduce the exhaust gas in the crankcase into the intake manifold to reduce the harmful gas in the engine exhaust.

2. Keep the pressure in the crankcase below atmospheric pressure (78.4kPa for Dongfeng EQ6 100 engine) to reduce oil leakage.

3. Keep the crankcase ventilated and engine oil fresh. One-way valves also have a certain relationship with fuel economy. If the engine oil in the crankcase deteriorates, becomes dirty and blocks the check valve, the vacuum degree of the intake manifold will increase with the increase of the throttle opening, so the air velocity at the throat of the carburetor will increase, the oil output of the fuel injector will also increase, and the fuel consumption will also increase.

Therefore, Chuanqi GA5 has no crankshaft ventilation check valve to reduce fuel consumption.