Embodiments of engine systems for improved engine cooling and work production are disclosed herein. A working fluid can be injected into a combustion chamber or an engine during any portion of an energy cycle to cool the engine and/or to produce useful work in addition to work generated by combustion events in the chamber. The system can include a monitoring system configured to measure conditions within individual combustion chambers. Based on the interior conditions of the chamber, the system can adaptively inject working fluid mixtures into the engine. The engine can be part of a cascading series of engines including a primary engine and a secondary engine that receives fluids from the primary engine and generates energy from the fluids.