The Marnoch heat engine (MHE) is a new type of heat engine currently under development at the University of Ontario Institute of Technology. The MHE can use waste or collected heat at temperatures that are currently unusable or not eco- nomically viable to use by conventional technologies. The MHE operates by using a heat source to heat the air in one heat exchanger and cool the air in another. This creates a pressure di erence. This pressure di erence drives a two-way piston connected to a ywheel. A generator connected to the ywheel converts the me- chanical energy of the ywheel into electricity. This thesis presents a simulation of the current MHE prototype. The simulation is designed to be easily customized to allow it to model the performance of future possible MHE installations and predict their performance. The simulation is shown to accurately model the performance of the MHE prototype by running under conditions similar to those found in the lab, and comparing its results to collected data from the prototype. Simulations were also run to show the model's ability to model possible applications with di erent operating conditions and physical components. / UOIT