The results of the application of the Jet Dispersed Combustion (JDC) method  to an actual piston engine are presented. The influence of the gas (air) jet action introduced dynamically in the engine combustion chamber on pressure traces is demonstrated, for various jet directions. The investigations revealed significant positive influence of the injection on the pressure profiles at various engine operational conditions. The results of the investigations confirmed that the promising features of the JDC method, observed before at the conditions being far from engine reality, can be utilized in the actual engine. The attempts to explain the combustion mechanism introduced by the JDC method are also reported.