Introduction
The cylinder block (shown below) is generally a single unit made from cast iron. In a liquid-cooled diesel, the block provides the structure and rigid frame for the engine's cylinders, water coolant and oil passages, and support for the crankshaft and camshaft bearings.
Additional Resources
https://www.sciencedirect.com/topics/engineering/cylinder-blocks
https://studentlesson.com/cylinder-block-materials-functions-types-diagram-issues
https://en.wikipedia.org/wiki/Engine_block