Only seldom can one look this far into a cylinder block. In this case it's an open-deck-construction. Looking from the top, the five main bearings of the crankshaft are visible. Obviously, the coolant is only found in the hollow cavities immediately surrounding the cylinders. The depth of the cooling cavities can be seen in the cylinders 1 and 4. The block is presumably cast around the cast iron cylinder sleeves.
For just this type of cylinder, there is a new process whereby they are treated with laser, since for the optimum lubrication of the pistons and the flawless function of the piston rings, the cylinder sleeve needs a certain surface coarseness. Previously they were given a cross-hatch grinding. The bombardment with a laser beam rather causes tiny indentations for the engine oil on the surface. These also develop partly through the graphite flake found in the cast iron. The cylinder receives a different crystaline structure, is less rough and the parts that slide on each other have a shorter running-in period. The oil consumption is distinctly reduced. 02/11

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