Study on Different Flame Jet Ignition Variants in a Stratified Charge Spark Ignition Engine

The paper presents some experimental results regarding a stratified charge spark ignition engine. We have applied the divided combustion chamber concept, using a flame jet in order to ignite the fuel-air mixture. The fueling system was a combined one: the cylinder head combustion chamber (secondary, auxiliary) was fueled by direct fuel injection, while the main combustion chamber was fueled with lean mixture by the means of a carburetor. During the tests we have used two types of main combustion chamber and three types of secondary combustion chamber. Thus, we had the possibility to use different compression ratios, starting with the lower ones, imposed by the less volatile fuels and ending with the higher ones, that led to the highest output power and a steady working process. In the meantime, three types of spark plugs were tested. We have also studied the HC and CO emissions, as well as the fuel consumption.