In previous articles, we discussed the major systems that make up an automobile. Today, we’ll be taking a look at the main component of drive train of your car: the engine. The drive train includes the engine, transmission, drive shafts, and axles. There are several sub-systems that support the drive train, such as cooling, lubrication, fuel, steering, and exhaust.

The first part of the drive train is the engine. Opening your hood and seeing all the hoses, belts, gears, wires, pulleys, bottles filled with pretty colored fluids, and government warning stickers can get confusing, but the engine function is not, and has not changed in theory since Otto invented the gasoline engine.

At its core, an engine is a solid piece of cast metal or aluminum with a bunch of holes drilled in it, called the engine block. The biggest holes or bores in the engine are the the cylinders. Most car engines have four, six, or eight cylinders. Inside each cylinder is a piston, whose sole purpose is to go up and down, turning a crankshaft aound and around at the bottom. In it’s “up” position, the piston creates a small compartment at the top of the cylinder which is filled with the pressurized gasoline vapors and air. The small spark, ignites the gasoline/air mix, thus driving the piston down. The pistons in the engine are attached to the crankshaft at different positions, so as each piston takes its turn in being driven down, it pushes another piston up. All of these pistons being driven up and down turn the crankshaft, which gives your car power to get up and go.

The “subsassemblies” of the engine are equally important, though they don’t all directly make you move. The cooling system pumps water or coolant through a series of pipes and hoses from the engine to the radiator. The radiator receives hot water from the engine, cools the water down, then sends it back to the engine. This keeps the engine temperature around 190 degrees Fahrenheit. If the engine’s temperature rises above about 220 degrees, it cannot work properly, and will usually shut down from being heat damaged. Requiring a replacement engine.

The lubrication system pumps oil through the moving parts of the engine to keep them lubricated, and to remove dirt and grime by filtering the oil as it cycles through. Oil breaks down quickly, so most manufacturers suggest changing the motor oil and oil filter 3,000 to 5,000 miles.

The fuel delivery system pretty much does what its name says: it delivers gasoline form the gas tank to the engine. In the gas tank is an electric fuel pump which drives gas from the tank, through a fuel filter, and into the cylinders.

Older engines used a practically obsolete component on the top of the engine called a carburetor to mix air and fuel for burning in each cylinder. In the late 1980s computer controlled fuel injection became more popular on the market, and today all cars are fuel injected. Fuel injection makes automated adjustments on the fly, letting the engine operate more efficiently in different environments.

A simplified version of engine theory and operation. We have a variety of articles on engine function delving deeper in the separate components of your engine and how they work. GotEngines.com, the largest and most quality oriented engine supplier in North America brings all of these posts to you as a courtesy. Enjoy.