Aircraft Induction Systems and Their Types

With an induction system, atmospheric air can be drawn into an engine, mixed with fuel, and delivered into a cylinder for ignition. To capture air, an intake port will be situated on the front of the engine cowling with an air filter being provided to deter any dust or contaminants from entering the system. For the sake of redundancy, an alternate source of air will also be provided, such as from the engine cowling itself. When discussing general aviation aircraft with smaller engines, carburetor and fuel injection systems are the two primary choices, and it may be very beneficial to have a basic understanding of their differences. While carburetor systems mix fuel and air within their assembly prior to it entering the intake manifold, fuel injection systems are designed to mix fuel and air directly before it enters each cylinder.
 
Carburetors themselves can further be separated into float- and pressure-type carburetors, the float-type system being the most popular option. With a float-type carburetor, air is supplied to the carburetor through a filtered port before passing through a narrow venturi. As it moves through this section, a low-pressure area is produced, allowing for fuel to be forced into the airstream so that proper mixing can be conducted. With pressure-type carburetors, fuel is delivered through a fuel pump above atmospheric pressure for enhanced vaporization. While pressure-type carburetors have increased protection from vaporization icing, carburetors generally need anti-icing or heating systems to ensure safety.
 
While carburetors have long served a wide variety of aircraft, they have since been superseded by fuel-injection systems in a variety of ways. For example, fuel-injection systems face less risk of icing, have improved acceleration, and ensure a more efficient fuel economy. Like carburetors, fuel-injection systems may vary in their exact makeup, though common assembly elements consist of an airflow section, regulator section, and a fuel metering section.
 
During the operation of fuel-injection systems, fuel is pressurized and delivered prior to combustion chamber inlet ports. Depending on whether a continuous flow or direct injection system is used, fuel may be continuously supplied to each inlet port at a specific pressure or injected directly into the chamber while bypassing the inlet valve. As stated before, fuel-injection systems offer a number of advantages over the conventional carburetor, though this comes at the cost of higher price points, more complex assemblies, and potential vapor lock in fuel lines.
 
With a better understanding of aircraft induction systems and the common types that are available, you can be in a better position to narrow down particular parts you may require for a first time installation or replacement project. Here on Aerospace Exchange, we offer access to countless ready-for-purchase parts, all of which trace back to leading manufacturers that we trust. Take the time to explore our offerings as you see fit, and our team members are always on standby to assist you throughout the purchasing process with competitive quotes for your comparisons, one-on-one consultation, and more. If you have any further questions or concerns, be sure to give us a call or email at your earliest convenience!