This resource on internal combustion engines comes from a mechanical engineering professor at Colorado State University. It is essentially an online textbook with three main chapters, which cover the topics of thermodynamics, heat transfer, and fluid mechanics involved in engine operation. Users should have an understanding of basic engine components, and a background in calculus would be helpful. Some of the material is fairly conceptual, while other parts involve analytical derivations. Many sections of the site have Java applets that effectively illustrate physical properties and dynamic processes.