A pressure surface is propelled within an engine chamber. Air is introduced into the chamber. The air in the chamber is compressed with the pressure surface. The compressed air is charged with fuel. The fuel is combusted to propel the pressure surface within the chamber. The air and the combusted fuel are exhausted from the chamber. A turbocharger is powered with the exhaust to compress air to an extremely high level, 20+ atmospheres. The air compressed by the turbocharger is passed into the chamber to propel the pressure surface in the chamber without additional fuel. Since compressing the high pressure air in the chamber would cancel the gains of the previous cycle and possibly damage the engine, this invention proposes to open the exhaust valve at the bottom of the intake stroke to relieve the excess pressure, close the exhaust valve and compress the remaining air in the cylinder.