Technical News

What Is Cylinder Block?


diesel cylinder block is the major components of an automobile reciprocating piston engine, besides the block,  the engine including other spare parts like oil pan, cylinder head, intake manifold, exhaust manifold, crankshaft, flywheel, camshaft, oil seals, bearings, connecting rod, piston, piston rings, valve train etc.

CAT 3306 BLOCK 1N3576

3306 BLOCK 1N3576

The diesel cylinder block is the portion of the engine between the cylinder head and oil pan and is the supporting structure for the entire engine. All the engine parts are mounted on it or in it and this holds the parts in alignment. Body group is mainly made up of the cylinder block, crankcase, cylinder head and cylinder pad and other components. Large diameter holes in the block-castings form the cylinder bores required to guide the pistons. These holes are called bores as they are made by boring. The cylinders are provided with a web or bulkhead to support the crankshaft and head attachments. Each main bearing bulkhead supports both a cam bearing and a main bearing. The cylinders are surrounded by cooling passages. The block has drilled passages for the flow of coolant and lubricating oil separately. When a curved passage is needed, intersecting drilled holes are used. After oil holes are drilled the unneeded open ends are capped by pipe plugs, steel balls, or cup-type soft plugs. The head, pan, and timing cover are fixed to the block with sealed joints for eliminating leakage. Gaskets are used in the joints to take up machining irregularities and to absorb variations due to pressure and temperature extremities.

The cylinder head is fastened to the top surface of the block, called the block deck. The deck has a smooth surface to seal against the head gasket. In most skirtless cylinder designs, the cooling passages extend nearly to the bottom of the cylinder. In skirted cylinder designs, the cooling passages are limited to the upper portion of the cylinder.