Method of controlling ignition timing of compression ignition engine of premixed mixture type

The invention relates to a method of controlling the timing of ignition of a compression ignition internal combustion engine of a premixed mixture type in which a premixed gas is self-ignited through compression by a piston (2), the volume of fuel spray impinging upon the inner wall surface of a combustion chamber (1) is continuously or stepwise increased as the engine speed is changed from a low value to a high value, and which can optimumly control the timing of compression ignition in accordance with an operating condition of the engine at a low cost without complicating the apparatus configuration.