The engine in a car is made up of several components that all work together to enable the car to move. The bottom block is the primary housing of the engine, known as the cylinder block including the cylinders and the components the bottom block houses, which are the pistons, connecting rods, crankshaft, and bearings.
The cylinder block is a strong cast iron or aluminium structure, usually referred to as the section of the engine situated between the cylinder head/s and the sump or oil pan. Its role is to provide structural support to the engine as a whole. The cylinder head is, however, sometimes referred to as being a part of the cylinder/bottom block, including the cooling passages, exhaust and intake ports and passages, contained in the cylinder head. The bottom block functions as a solid mount for all of the engine components which are either housed in it or mounted to it. It also functions to keep the components in perfect alignment with each other.
The cylinder head is fixed on top of the cylinder block/bottom block, forming the top of the combustion chamber. Sandwiched between the cylinder head and cylinder block, acting as a sealant, is the head gasket. The job of the cylinder head is an important one. The cylinder head is comprised of a series of passages that carry the air and fuel combination needed for combustion to the cylinders; the liquid coolant, needed to keep the engine cool; and harmful fumes (produced by the engine in the process of combustion) from the exhaust valves to the exhaust manifold and away from the vehicle. In an air-cooled engine, the cylinder head and cylinder block have fins on the outside that allows cool air, generated by a fan which is powered by the engine, to flow through the engine and keep it cool.
Although built to be strong and resistant to wear, the bottom block is subjected to pressure from the process of combustion, high temperatures and vibration from the engine when it is running, all of which will eventually cause stress and wear. The bottom block can also deteriorate as a result of corrosion over time. When you need to buy a new bottom block for your vehicle, the bottom block is the ideal replacement part. Specifically manufactured for the make and model of your vehicle, it is designed to be completely compatible, providing optimum performance and a longer working life.