| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a spark ignition type internal combustion engine capable of assuring an engine output while a geometric compression ratio being kept at a high compression ratio.SOLUTION: In this spark ignition type internal combustion engine, a geometric compression ratio of an engine main body is set to be 14 or more, an overlap period between an intake valve 8 and an exhaust valve 9 opened with a top dead center being held is set 35°CA or more in a low speed high load area, a spaced-apart distance between an upper surface 3a of a piston 3 kept at the top dead center and a lower surface 8a of the intake valve 8 kept in a closed state and a spaced-apart distance between the upper surface 3a of the piston 3 and a lower surface 9a of the exhaust valve 9 kept in a closed state are set to 5 mm or more, respectively, and a stroke S of the piston 3 is set to a length of 81.2 mm≤S≤0.977×B+18.2 mm with a bore diameter of a cylinder C being defined as B.</p> |
