This study presents a dynamic model of a gamma-type Stirling engine and examines variations of the crank rotational speed against time (Dynamic response). Kinematic relations of the engine linkages were determined and Lagrange formulations were formed for rigid body dynamics. Working gas pressures on each surface of the rigid bodies were calculated over time using a third order thermodynamic analysis code. A test setup was established for measuring dynamic and thermodynamic state variables of ST500engine. First, experiment data was used to validate the thermodynamic code results. Then the dynamic formulations combined with the thermodynamic code were simultaneously solved and the result is compared to ST500 dynamic response. Finally, using the whole dynamic model, new aspects of Stirling engine behavior were investigated. The dynamic thermodynamic combination of the model gives the opportunity to instantly calculate a precise open-loop response, which is the essential part of designing proper load controllers for inherently unstable Stirling engines. (C) 2015 Elsevier Ltd. All rights reserved.