An internal combustion engine is disclosed and includes a main cylinder and main piston that are relatively axially displaceable along a main axis to define a variable volume main working chamber. At least one valve is configured to admit air and fuel into the working chamber forming an air/fuel mixture. The main cylinder is configured to cause the air/fuel mixture in the main cylinder to spin rapidly enough to cause a substantive change in the heat capacity of the air/fuel mixture creating a spinning air/fuel mixture. The main cylinder and main piston are configured to compress the spinning air/fuel mixture to create an ignitable spinning air/fuel mixture. The spinning air/fuel mixture is ignited and the main cylinder and main piston are configured to extract mechanical energy from the ignited spinning air/fuel mixture. An exhaust valve is configured to exhaust combustion products from the main working chamber.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under Grant No. DE-AC02-09CH11466 and Grant No. DE-FG52-08NA28553 awarded by the Department of Energy and Grant No. HDTRA1-11-1-0037 awarded by the Defense Threat Reduction Agency, administered by the Office of Naval Research. The government has certain rights in the invention.