A common rail injection system was applied to port-loop and uniflow scavenged two-stroke DI-Diesel engines. While the uniflow scavenged configuration was operated with a swirl level comparable to that of 4-stroke DI-Diesel engines, no swirl motion was realized with the port-loop scavenged arrangement. The results show that, in spite of disadvantages in the mixture formation process, the high mixture formation energy observed with the common rail injection makes a swirl-free Diesel combustion possible. However, at part load the combustion process and emission level with the port-loop scavenged engine is not satisfactory. At full load, disadvantages in the scavenging process are observed in addition to the poorer mixture formation with the loop scavenged two-stroke concept. Consequently, the expected specific power output of the port-loop scavenged arrangement is with 20 kW/l far lower than about 45 kW/l predicted for the uniflow scavenged engine. The results regarding indicated specific power output and emissions with the uniflow scavenged arrangement are comparable to that with 4-stroke 4-valve DI-Diesel engines equipped with common rail injection systems.