Özet:

In the buji-and-fire engines, the geometric compression rate can be changed according to the amount of filling in the cylinder and the engine performance can be increased. In these engines, since the actual compression rate varies according to the amount of filling received in the cylinder, the geometrically designed compression rate is only obtained as the actual compression rate in full gas and full load conditions. This situation requires the variable compression rate according to the quantity of the cylinder filling to improve performance and fuel economy in the boji-and-burning engines. It is necessary to increase the compression rate to improve combustion efficiency in partial loads, fuel savings and emissions, while in high loads and low speed conditions of the engine, the compression rate is to be somewhat reduced to prevent possible shocks and hard work. In this study, the power, moment, specific fuel consumption, cylinder pressure, exhaust gas temperature, combustion room surface volume ratio, thermal efficiency and combustion advance motor performance parameters have been studied with the compression ratio and the use of variable compression ratio engines for fuel economy was recommended.