How Does a Carburetor Work?

A carburetor is a device used in internal combustion engines to mix air and fuel in the correct proportion for efficient combustion. Up until the 1990s, carburetors were widely used in gasoline engines powering automobiles, motorcycles, and other vehicles before the pervasive implementation of fuel injection systems.


A four-barrel carburetor.
A four-barrel carburetor.

History of the Carburetor

The carburetor has a long history that dates to the early days of the internal combustion engine. The first carburetor-like device was developed by a Frenchman named Jean Joseph √Čtienne Lenoir in 1860. Lenoir’s apparatus used a simple spray nozzle to mix fuel and air, but it was not very efficient.

The first true carburetor was invented by German engineer Wilhelm Maybach in the 1880s. Maybach’s carburetor was a simple device that used a float to regulate the fuel level and a needle valve to control the flow of fuel. It was first used in Maybach’s internal combustion engine, which powered the world’s first four-wheeled automobile, the 1886 Benz Patent Motorwagen. The Maybach name, incidentally, still adorns high-end German models, notably the Mercedes-Maybach.

Over the next few decades, carburetors continued to evolve and improve. In the early 20th century, American engineer Frederick William Lanchester introduced the idea of the venturi tube, which became a key component of modern carburetors. By the 1920s and 1930s, carburetors became more sophisticated and were used in a wide range of vehicles, including airplanes, boats, and motorcycles.

In the 1960s and 1970s, carburetors faced increasing competition from electronic fuel injection systems, which offered better fuel efficiency and lower emissions. However, carburetors remained in use in many applications, particularly in small engines such as those used in lawnmowers and other outdoor equipment.

How Carburetors Work

The carburetor works by regulating the flow of air and fuel into the engine. Specifically, the air is drawn in through a narrow passage called the venturi, which increases its speed and reduces its pressure. As the air flows through the venturi, it pulls the fuel from the carburetor’s float bowl, creating a mixture of air and fuel that is sent to the engine’s cylinders for combustion.

The carburetor has various components including the float, the needle valve, and the throttle plate, which all work together to control the amount of fuel and air that enters the engine. The float maintains the fuel level in the float bowl. The needle valve regulates the flow of fuel into the carburetor. Finally, the throttle plate controls the amount of air entering the engine.

Fuel Injection Systems

Although carburetors are still used in some applications, fuel injection systems replaced them in modern engines due to their greater efficiency and reliability. Indeed, it was in 1991 when the last two mass-produced models stopped offering carburetors.

Firstly, it was the Ford Crown Victoria with the 5.8-liter V8 engine. Secondly, it was the Subaru Justy powered by a three-cylinder engine. Lastly, you can still find carburetors in power equipment, but as far as automobiles go, fuel injection reigns supreme.


References

Francisco, M. A. (2021, December 8). The Secret History Of The First Car Ever Made. Grunge.

Tietz, T. (2021, February 9). Automobile Pioneer Wilhelm Maybach. SciHi Blog.

Laukkonen, JD (2013, October 20). What is a Carburetor? CrankSHIFT.

Strohl, D. (2021, July 29). Just how long did the carburetor hold out against fuel injection in passenger vehicles?. Hemmings.


Photo Attribution


By Scheinwerfermann – Own work, Public Domain, via Wikimedia Commons.

Rich Niewiroski Jr., CC BY 2.5, via Wikimedia Commons

Matt Keegan
Author: Matthew Keegan
Matt Keegan is a journalist, media professional, and owner of this website. He has an extensive writing background and has covered the automotive sector continuously since 2004. When not driving and evaluating new vehicles, Matt enjoys spending his time outdoors.

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