Abstract: An engine equipped with an alcohol vaporization injection system operates as a four stroke cycle diesel engine that transfers the heat of exiting exhaust gases and cylinder head walls to the fuel the engine runs on alcohol. The alcohol becomes vaporized and its pressure is high enough so that when a valve is opened between the high pressure fuel line and the combustion chamber (when it is at the peak of its compression ratio) enough alcohol will enter the combustion chamber to allow proper combustion.The overall advantages to this type of alcohol vaporization injection system is that it adds relatively few new mechanisms to the spark ignition four cycle internal combustion engine to enable it to operate as a diesel engine with a high thermal efficiency.