The document summarizes the six-stroke engine, an innovative engine design that combines aspects of two-stroke and four-stroke engines. It works by adding an additional piston inside the cylinder head that opens and closes intake and exhaust ports. This increases power and torque over a four-stroke by up to 35% while reducing weight and complexity. The six-stroke engine provides thermodynamic advantages through increased expansion and more constant combustion. It offers improved efficiency and performance compared to conventional engines.