How the automotive engine works

The Engine

Technically speaking, your car’s engine is not a motor, even though everybody uses the two words interchangeably. A “motor”converts electrical  energy into mechanical work such as the ecm and starter motor that cranks your engine. An “engine,” on the other hand, is a machine that converts heat energy into mechanical work. Your engine ecm does this by forcing the engine to burn gasoline inside its combustion chambers. When gasoline and air are mixed together in the correct proportions (parts of air to one component gasoline is regarded as perfect) and ignited by a spark, the mixture explodes, creating tremendous heat and pressure. Even though, combustion occurs in a split second, the ecm insures it does so in a controlled manner. When the spark ignites the mixture, a “flame front” sweeps out from the point of ignition like a quickly expanding balloon until all the fuel mixture is consumed. This causes a sharp rise in cylinder pressure, and ecm performance  which pushes the piston down and turns the crankshaft. Therefore, heat energy is transformed into helpful mechanical work to power your automobile down the road. Pressing down on the accelerator pedal opens up the engine throttle, which makes it possible for more air and fuel to be drawn into the engine. This increases the density of the fuel mixture in every of the engine’s cylinders, which in turn increases the intensity of cylinder pressures when the mixture is ignited. As a result, the engine ecm develops far more power, permitting it to either run faster or work harder, depending on the load. Let off on the accelerator pedal and the quantity of air and fuel are decreased. Cylinder pressures drops and the engine ecm slows down.

In a way, you can feel of an internal combustion engine as an air pump. The ecm sends signals to the throttle which allows it to pump more air by way of itself, and the greater the volume of air (and fuel, the greater the ecm output. That’s why larger engines need a high performance ecm to create much more horsepower than smaller ones. They have a greater pumping capacity. Sadly, internal combustion engines are not really efficient when it comes to making excellent use of the heat energy produced by combustion. Only about a third of the heat energy is truly employed to drive the automobile. Almost a third is lost when the hot exhaust gases exit
out the tailpipe. By the time the piston reaches the lower limit of its travel. cylinder
pressure has dropped considerably from its peak which occurred shortly soon after ignition.
The engine ecm has gotten all it can from the expanding combustion gases, yet heat energy remains which need to now be dumped out the exhaust so the cylinder can repeat the procedure over once more with a fresh charge of air and fuel One more 20 to 25 percent of the heat produced throughout combustion is lost to the cooling program.

As the engine burns fuel. It begins to heat up. Were it not for the cooling system,
the engine ecm would continue to develop up heat until it eventually melted and destroyed  the ecm. So heat loss by way of this path is unavoidable. Another form of loss is overcoming internal friction: piston rings rubbing against the cylinders’,
cam lobes rubbing against their lifters valves sliding up and down in their valve
guides the crankshaft turning in its bearings etc. Yet frictional losses aren’t as great as you may possibly imagine. It’s only about 5 to 8 percent for most engines. Even so, it’s an additional loss that comes out of the beneficial work produced by combustion.
A percentage of the engine’s remaining power is also needed to drive “parasitic” accessories such as the water pump, alternator, power steering pump, ecm and air conditioning compressor. There are also frictional losses in the engine ecm, transmission, drivetrain, and tires.