The paper addresses the problem of the influence of the LPG injection technique on the course and effects of the SI engine work cycle. Described test-stand experiments were done using SI engine fuelled with simultaneous and sequential injection of vaporized LPG into intake manifold. For both cases of fuelling experiments were done at the same, steady conditions of engine operation. Analyzed engine parameters were: torque, indicated pressure and concentrations of toxic gaseous emissions. These quantities were compared correspondingly for both types of fuelling technique.

The paper presents the results of the analysis of the simulation tests of the flow of fuel through the fuel rail for the designed radial aircraft engine. A 3D model has been developed for CFD calculations including the fuel rail and elements supplying the fuel to the injectors. Simulation tests were carried out using Star-CD software. The objective of simulation tests has been to determine flow characteristics of the fuel rail design. This design is atypical due to: the shape of the rail - a torus with internal diameter 630 mm, and the fuel flow rate of approximately 30 l/min. Analysis covered flow velocity and pressure at selected points of the design. The tests were conducted for two cases. The first covered constant fuel flow from all injectors; the second covered dynamic states that take place when the injector is opened. The purpose of these tests was to check the possibility of using this solution for prototype purposes.