Abstract
Increasing the fuel efficiency has been one of the main development topics in gasoline engine. Electro mechanical valve system engine was considered as future technology for low fuel consumption. As it can be achieved by cylinder deactivation and low pumping losses with throttle less load control. The valve activation energy in EMV is electrical energy in which was converter from mechanical energy of engine. The more energy was consumed for valve operation in
EMV. Therefore in this study fuel consumption between EMV and normal engine was compared in cylinder deactivation condition. For the cylinder deactivation operation, normal engine has better fuel economy than EMV engine. The differences were caused by the difference of valve operation energy. normal operation condition. And with EMV engine, fuel consumption was compared between throttle less condition and throttle condition. Through this test, the dominant factor for the reduction of fuel consumption in throttle less operation was revealed. And the main factor was residual molecular fraction. To find out the possibility of this effect in throttle engine, load was controlled by throttle and valve timing was changed with certain duration. Then fuel consumption was not much different between two.