Two exciting ways that fuel injection systems are being perfected is the replacement of moving parts with stationary ones and solid parts with intangible substances. By reducing the number of mechanical parts, car manufacturers hope to reduce production costs and create devices that are less susceptible to breakdown due to physical stress.
Now, I’ve been in favor of simplification ever since my mother taught me to always buy the washing machine with the fewest gadgets on the principle that the fewer parts involved, the fewer things there are that can break down.
But I keep having this fantasy that if they continue to replace mechanical car parts with miniaturized and computerized equipment, eventually I may lift the hood of my vehicle and find nothing but a little black box! At that point, when things go wrong, I’ll probably have to seek the services of a wizard rather than a technician! The upside is that using less metal, plastic, and rubber places less strain on the world’s dwindling supply of raw materials.
It also reduces the amount of energy consumed by production (as well as driving) and the number of disposal facilities required to process all the worn and broken stuff that gets thrown away. So let’s hope that the trend continues, wizards and all.
Throttle-body fuel injection
Throttle-body fuel injection (TBI) was the first fuel injection system to become popular as carburetors were being phased out. This system is less complicated than the multi-port fuel injection systems found on more recent vehicles (refer to the preceding sections), but it’s also less efficient.
Instead of using individual fuel injectors to pump the fuel into each cylinder, the TBI system mixes the fuel and air together right in the throttle assembly of the vehicle. Along the way, sensors monitor air flow, throttle position, temperature, and other factors and report back to the ECU (engine control unit).
He Engine Block: Where the Fuel
Whether accomplished through a fuel injection system or a carburetor, after the air and fuel unite in the form of a vapor and the spark plugs are ready to provide that all-important spark of ignition, all that’s needed is a spot for that passionate meeting to take place. The rendezvous occurs in your engine’s cylinders, and it’s truly a triumph of timing (as any successful rendezvous must be!).
Major engine components
At the top are the cylinder heads. These contain the mechanisms that allow the valves to open and close, letting the fuel/air mixture into the cylinders and allowing the burnt exhaust gases to leave. Below the cylinder heads is the engine block itself. This piece contains the cylinders, which contain the pistons.
Engines that have a single row of cylinders are called in-line engines (sometimes called straight engines). V-type engines have two parallel rows of cylinders set on an angle to each other. On rotary engines (found on some Mazdas), there’s a single large internal chamber inside which a three-lobed, or triangular, rotor revolves.
The rotor makes an eccentric or uneven revolution, continually forming smaller chambers in which occur the same four-stroke power cycle as in a conventional internal combustion engine (the next section describes the four-stroke power cycle).