The cylinder block is cast from cast iron. The thickness of the cylinder block walls is reduced, and the rigidity of the cylinder block is increased by increasing its height. The cylinder block is sleeveless. To improve cooling and reduce oil consumption for burning, the cylinder block has cross-shaped channels through which the coolant circulates, as well as oil channels for lubrication of the crankshaft, connecting rods, pistons, oil supply to the oil nozzles and to the cylinder head.