The Stirling engine is a renewable way to confront the lack of fossil energy over the word, to reduce the pollution and to use a free way of energy. Actually, these engines are used to produce electricity, to pump water, etc. Unfortunately, this type of engine is the seat of several thermal and mechanical losses. The dissymmetry of heat transfer inside the Stirling engine regenerator’s is one of the important phenomena which consume a part of the produced energy.
This paper propose a series of experiments which permits to determine the causes of the dissymmetry of heat transfer between both regenerator sides in a Gamma type Stirling engine. A central composite design was developed to detect the influence of following independent variables: heating temperature, loading pressure, cooling water flow rate and operation time on the regenerator dissymmetry of the heat transfer. The influence of each parameter and the effect of the interaction between two or three parameters on the studied phenomenon are presented and discussed. Using the surface response method, it appears that the heating temperature and the initial charge pressure are the most influencing parameters. The damage caused by this phenomenon will be presented too.