The engine block is the linchpin of vehicles which run on internal combustion, providing the powerhouse for the vehicle. The engine block is termed a block because it is usually a solid cast car part, housing the cylinders and their components inside a cooled and lubricated crankcase. The engine block is designed to be extremely strong and sturdy, because failure of the engine block results in failure of the car, which will not function until the engine block is replaced or repaired.
The engine block is typically made of cast iron, although in the late 1990s engine blocks made from other experimental materials were being used in prototype cars with the hope of developing more lightweight, efficient vehicles. A cast iron engine block can comprise a substantial portion of the weight of the car, and usually requires multiple people to be removed and worked on safely.
Working from the outside in, the engine block starts with a solid metal outside, designed to seal everything inside. A number of channels and passages inside comprise the cooling jacket, and are designed to deliver water from the radiator to all the hot sections of the engine, preventing overheating. After the water is circulated in the engine, it returns to the radiator to be cooled by the fan and sent back through the engine.
The core of the engine block is the cylinders, capped by the cylinder head. The number of cylinders determines the size and placement of the engine block, with most cars having between four and eight cylinders. These cylinders house pistons, which provide motive energy for the vehicle through a series of controlled explosions inside the cylinders which push the pistons out, moving the crankshaft of the vehicle.
Attached to the bottom of the engine block is the oil pan, which seals in the lubricating oil for the engine. Periodically the oil for the car must be changed, and the oil pan is drained and refilled to remove the older oil, which has lost viscosity and picked up impurities.
The engine block is the collective term which refers to the crankcase and all the components which fill it, including gaskets, valves, and seals. Because of the importance of the engine block in the functioning of the car, it is recommended that drivers perform regular maintenance on their vehicles to prevent damage to internal parts which can be caused by overheating, insufficient oil, and other easily preventable situations.
The engine block becomes extremely hot during normal operations, and drivers should be cautious about touching it until it has cooled sufficiently.