The engine block is an integrated structure comprising the cylinders of a reciprocating engine and often some or all of their associated surrounding structures like coolant passages, intake and exhaust passages and ports and crankcase.

The engine bock,is the largest among car parts and it usually takes 20-25% of the total weight of the engine.The engine block,is the housing of hundreds of parts in modern engines and for many years,it has been manufactured in cast iron alloys.As the years pass and as the technology advances,the engines becomes more complicated,engineers found new materials to reduce the weight of the engine block and also increase its strength and resistance.