The cylinder block is the base part on which various mechanisms and auxiliary units of the engine are mounted. It is cast from special low-alloy high-strength cast iron. Cylinders are bored directly in the block and do not have insert sleeves. Both pistons and cylinders are divided into 5 classes according to diameter (through 0.01 mm): A, B, C, D, E. Cylinder class (latin letter) knocked out on the bottom plane of the block against each cylinder.
In the lower part of the cylinder block there are five bearings for the crankshaft main journals with thin-walled steel-aluminum liners. Bearing caps are attached to the block with self-locking bolts, which cannot be replaced with any other ones.
The holes for the main bearings are machined complete with caps, so the bearing caps are not interchangeable and have risks on the outer surface to distinguish (see fig. 50). The bearing supports and their corresponding covers are counted from the front end of the cylinder block. In addition, each cylinder block and its main bearing caps (see fig. 50) are branded with the same conditional number, so that when repairing the engine, you do not accidentally put the covers in "stranger" cylinder block. On the cylinder block, this number is knocked out on its lower plane near the oil filter.
In the left front part of the cylinder block there is a small cavity in which the oil pump drive shaft and the ignition distributor are installed parallel to the engine axis (see fig. 24). The roller rotates in two steel-aluminum bushings pressed into the cylinder block. Since 1984, the rear hub has been made of sintered metal. Spare parts are supplied with bushings of nominal and repair size with an inner diameter reduced by 0.3 mm.
The cylinder blocks of the 2101 and 21011 engines have different cylinder diameters and are therefore not interchangeable. They are easily identified by the model number molded on the left side of the cylinder block.