The crankcase is the skeleton of the engine – it houses the cylinders, numerous hoses and pipes run through the component, and countless heavy engine components are attached to it. However, it not only supports the other components, it must also withstand the immense forces generated by combustion and piston movement. In addition, oil heated to over 100 degrees Celsius flows through the crankcase. Extreme pressures and temperatures are one reason why a great deal of precision is required during production to ensure that a crankcase can withstand the stresses. Tolerances of a few hundredths of a millimetre are just as important. Production requires a great deal of expertise and experience. So how is a crankcase made?
A 20-cylinder crankcase from the 4000 series weighs 2.4 tonnes in its raw state when it is delivered from the foundry. A layman might think that the crankcase is already ready for assembly. After all, it already has recesses for the cylinders. However, during assembly, it would quickly become apparent that the associated add-on parts do not fit. The crankshaft would grind, and the screws would not grip. Four production phases and four to five days of work lie between the anthracite-grey raw part and the shiny silver crankcase ready for assembly.