Although some information is currently available on the LTD Stirling engine, there still remains room for further research. In particular a detailed investigation is lacking into the LTD Stirling engine using solar energy as a heat source. As a consequence, in this paper, the testing of the performance of a LTD Stirling engine using simulated solar energy is presented. The LTD Stirling engine tested in this paper is a kinematics, single-acting, four powerpiston, gamma-configuration. Non-pressurized air is used as a working fluid and a solar simulator fabricated from four 1000 W tungsten halogen lamps is used as a heat source. Since the gamma-configuration provides a large regenerator heat transfer area and is easy to be constructed, this is configuration which is used in this study.