Cylinder block, cylinder head and crankcase are the main stationary bodies of the automobile engine. They serve as support and enclosure for moving parts. Nowadays the cylinder block and crankcase form a single casting which gives a rigid structure. Ribs are cast in the crankcase to give it extra strength and to support the main and camshaft bearings.

Cylinder Block (Image Credit:the-nerd.org)

A cylinder block consists of three parts:

The round cylinder surface are given precision mirror finish by accurate grinding and honing processes. The cylinder block is usually made from gray cast iron and sometimes with addition of nickel and chromium.

Cylinder head is mounted on top of the block. Some parts attached to the cylinder block with sealing gaskets which provide good seal to prevent leakage of water, oil or gas. Some parts are attached with bolts and with other studs and nuts. Water cooled engines have passages surrounding each cylinder, valve and spark plug. The circulating water maintains the engine at its correct working temperature and avoids excessive expansion and hence distortion ultimately preventing the seizure of relative moving parts.