Archive for June, 2009
How Does A Car Engine Work?
A car engine is an internal combustion gas engine, which works on a four-stroke routine: intake, compression, power, and exhaust. These four strokes are made by the pistons, which travel up and down inside all of the cylinders of the enbgine. Each cylinder has its own intake valve, exhaust valve, spark plug, and piston. Gas comes in from the gas tank through the fuel lines, where it mixes with air and is atomized. The air-fuel mixture is what feeds into the cylinders and drives them.
The intake stroke starts while the intake valve of a cylinder opens, letting the air-fuel mixture in. The piston slides downward in the cylinder. This down motion creates a huge vacuum, which improves sucking in the air-fuel mixture.
Both valves are closed on the compression stroke. The piston goes upwards, compressing the air-fuel mixture up in the direction of the spark plug. This compression causes the fuel more volatile for easier ignition.
Both valves remain closed on the power stroke. The spark plug explodes the air-fuel mixture. The resulting explosion significantly forces the piston downward.
The exhaust stroke initiates when the exhaust valve opens. The piston is moving up yet again, forcing the left over byproducts of the burned air-fuel mixture out in the exhaust system.
The pistons are attached via a piston pin and connecting rod to the crankshaft. The crankshaft is not straight, but has high and low areas that help drive alternating pistons up and down. When the power stroke forces two of the pistons in a 4 cylinder engine down, it forcees on the crankshaft, which turns and at the same time moves up on the other two cylinders pistons. Everything is in continuous motion, half the pistons slide up while the other half travel down.
The intake and exhaust valves are moved similarly by the camshaft. The camshaft is also linked by gears to a distributor. Spark plugs are mounted to the distributor by plug wires. As the camshaft rotates, opening and closing the valves, it as well triggers the distributor, which makes the spark plugs ingnite at the right spot in the cycle.
The crankshaft and camshaft are coupled at the face of the engine with the timing chain or belt. This timing chain/belt must be properly aligned in order for the system to operate in constant harmony, with accurate timing.
The flywheel is bolted to the back of the crankshaft. Once you turn the key in the ignition, the starter engages the mechanism on the flywheel. This starts the whole action of the engine. As soon as the cylinders ignite, the engine incessantly moves itself with the four-stroke system.