Main dimensions of the cylinder block
The cylinder block is cast from special low-alloy high-strength cast iron. The cylinders are bored directly in the block and do not have insert liners. In the lower part of the cylinder block there are five supports for the crankshaft main bearings. The crankshaft main bearing caps are machined together with the cylinder block, so they are not interchangeable and have marks on the outer surface for distinction (see Fig. Marks on the main bearing caps and the cylinder block reference number).
The front part of the cylinder block houses the chain drive of the camshaft and the drive shaft of the auxiliary units (oil pump, ignition distributor and fuel pump). The roller rotates in two steel-aluminum bushings pressed into the cylinder block. Since 1984, the rear bushing has been made of metal ceramics. Bushings of nominal and repair sizes with an internal diameter reduced by 0.3 mm are supplied as spare parts.
The camshaft drive cavity is closed by a cover with a front self-tightening crankshaft oil seal. A rear crankshaft oil seal holder is attached to the cylinder block at the rear.
The cylinder block is closed from below by a stamped steel oil sump. Cork-rubber gaskets are installed between the cylinder block and the sump, as well as between the cylinder block and the camshaft drive cover.