THE AUTOMOTIVE ENGINE

The ENGINE is one of the most important part of the automobile, it serves as the source of power for propelling the vehicle and the source of power to the other automotive systems. basically the engine is a system that converts chemical energy into mechanical energy.
 The automobile uses an internal combustion engine and the most common types are the petrol engine and the diesel engine, that is they consume petrol or diesel fuel. The fuel burns in the engine to produce heat. This heat causes gas expansion, creating pressure inside the engine. The pressure moves internal engine parts to produce power. The engine is usually located in the front portion of the body. Placing the heavy engine in this position makes the vehicle safer in the event of a head-on collision. In a few vehicles, the engine is mounted in the rear to improve handling.

Basic Engine Parts

•  The block is metal casting that holds all the other engine parts in place.
•  The cylinder is a round hole bored (machined) in the block. It guides piston movement.
•  The piston is a cylindrical component that transfers the energy of combustion (burning of air-fuel mixture) to the connecting rod.
•  The rings seal the small gap around the sides of the piston. They keep combustion pressure and oil from leaking between the piston and the cylinder wall (cylinder surface).
•  The connecting rod links the piston to the crankshaft.
•  The crankshaft changes the reciprocating (up and- down) motion of the piston and rod into useful rotary (spinning) motion.
• The cylinder head covers and seals the top of the cylinder. It also holds the valves, rocker arms, and often, the camshaft.
•  The combustion chamber is a small cavity (hollow area) between the top of the piston and the bottom of the cylinder head. The burning of the air-fuel mixture occurs in the combustion chamber.
•  The valves open and close to control the flow of the air-fuel mixture into the combustion chamber and the exhaust gases out of the combustion chamber.
•  The camshaft controls the opening of the valves.
•  The valve springs keep the valves closed when they do not need to be open.
•  The rocker arms transfer camshaft action to the valves.
•  The lifters, or followers, ride on the camshaft and transfer motion to the other parts of the valve train.
• The flywheel helps keep the crankshaft turning smoothly. It also provides a large gear for the starting motor,