Fuel, air, and ignition. These are the three key ingredients of an engine’s power recipe. A well-mixed recipe requires just the right ratio of fuel to air. In a carbureted engine, that happens upstream of the cylinders in the carburetor. With a fuel-injected engine, the mixture takes place at each individual cylinder.
Carburetors have the advantage of being simple to operate, but they are a shotgun to fuel injection’s rifle. Fuel injectors are dedicated nozzles at each cylinder that can be calibrated to dispense just the right amount of fuel. Since fuel is used for both power and cooling, that more precise method is important in powerful engines.
The system includes a pump to draw the fuel, a box where the throttle controls the amount of incoming air, an injector manifold, and a fuel line and nozzle for each cylinder. It’s easy to spot whether or not an aircraft has fuel injection by looking for the manifold, which typically sits directly on top of the bank of cylinders.
The necessary vaporization and fuel/air mixing happens in the nozzle. It is nothing more than a metered opening in the fuel line and a screened opening to bring in outside air.
