Evaluation methods of Scavenging Port Injection for a CNG Fueled Marine Racing 2-stroke Engine

Abstract

The objective of the present study is to examine the possibility to realize stratified combustion in a 2-stroke spark-ignition engine fueled with CNG. A two-cylinder racing engine with the stroke volume of 397cc was used. Through a preliminary experiment, utilizing several techniques of flow rate measurement, a reliable measurement of CNG flow rate could be established and some gas dynamic effect in engine was suggested. By applying Scavenging port injection, remarkable improvement of BSFC can clearly be shown in comparison with the homogeneously charge operation with a gas mixer.