# Engines * [4 Stroke Engine Video](https://www.youtube.com/watch?v=Pu7g3uIG6Zo) * [Thermodynamic Integral](https://www.youtube.com/watch?v=2Uyqj09RZAI&list=PL8erL0pXF3JaJdUcmc_PeGV-vG5z87BkD&index=115)