Piston engines remain main power installation for many products of transport mechanical engineering. The aim of the paper is to study a structure of air flows in an admission system and a cylinder of an automobile engine at various designs of channels in a head of a cylinder block on the basis of physical and mathematical modeling. Results of modeling are qualitatively confirmed by experimental data of thermograms gained with the use of a thermal imaging photography method. The paper presents description of a mathematical model and a method of conducting laboratory experiments. The paper shows that the application of square and triangle channels leads to significant change of dynamics of flow in the admission system. In particular, in profiled channels of the cylinder head vortex structures are formed. It is established that the use of profiled channels in the admission system leads to large-scale turbulence in the engine cylinder. Common influence of mentioned gas dynamics phenomena may insignificantly decrease hydraulic resistance in the admission system and also may enhance processes of mixture formation and combustion in the cylinder of the piston engine.