I am for a mini air cooled diesel engine that is similar to this.
A 69.0 mm (2.72 in) cylinder bore and 65.0 mm (2.56 in) piston stroke give the 1B20 engine a total of 243 cc (14.83 cu-in) of displacement. Compression ratio rating is 22: 1. It produced from 2.2 HP (1.6 kW) at 1, 600 to 4.7 HP (3.5 kW) at 3, 600 rpm of maximum output.