The cylinder crankcase has a reinforcement section (4) formed from a high strength material e.g. cast iron, cast steel, and nodular graphite iron. The cylinder crankcase is formed from a separate cylinder running surface-water space unit (2) and a separate crankshaft housing (3). The cylinder crankcase is divided horizontally below the cylinder running surface. The separate cylinder running surface-water space unit and the separate crankshaft housing are formed from aluminum and/or magnesium alloy. An independent claim is also included for a method for manufacturing a cylinder crankcase.
