Seyed Shahabeddin Alaviyoun - M.Sc. of mechanical engineering,Irankhodro Powertrain Company (IPCO), Tehran, Iran
Peyman Sharghi - M.Sc. of mechanical engineering, Irankhodro Powertrain Company (IPCO), Tehran, Iran
Seyed Vahid Hosseini - PHD student of mechanical engineeringIrankhodro Powertrain Company (IPCO), Tehran, Iran

In this research, an investigation was performed on effect of turbocharger on crankcase ventilation of bi-fuel engine in a test cell with standard dynamometer. Blow-by flow was measured for two different configurations; standard oil circuit of turbocharger and external oil circuit of turbocharger. Differences between blow-by values of two configuration, specify amount of blow-by which produced by turbocharger. Results of experiment showed that at 5000 rpm and full load condition, maximum blow-by flow which caused by turbo charger was 11 l/min with gasoline and it was 11.27 l/min with CNG which was 30 percent of total blow by flow. During the test, Amount of oil which carried by blow-by (oil pull over) was measured for naturally aspirated and turbo charged engines. In order to measure amount of oil pull over, gravimetric measurement method was applied using an additional oil separator. The maximum amount of oil pull over at working point 5500 rpm and full load condition, for turbocharged engine was 7.97 g/hr and for naturally aspirated engine was 0.9 g/hr. In addition, turbocharged engines are generally paired with higher pressure values in the combustion chamber. Therefore, pressure of cylinders was measured and the relation between cylinder pressure and amount of blow by were investigated.

Blow-by gases; Turbocharger; Bi-fuel engine; Oil circuit; Oil pull over