The cylinder crankcase, code 11.01203-1644.C, is one of the most fundamental components in the MAN L21/31 engine. It serves as the foundation for the crankshaft and cylinder assemblies, ensuring structural rigidity and alignment. Engineered to withstand high thermal and mechanical loads, the crankcase supports efficient power transmission and vibration control. Its design ensures the entire engine structure maintains stability, making it vital for long-term performance in both marine and stationary installations.