Please Tell Us Your City

Understanding Carb...

February 20, 2015 15:24

The current-generation of cars come equipped with all the computers, sensors and gadgets, but the old four-wheel passenger vehicles used carburetor engine. Though No new cars use carburetors, it is important to understand how engines have evolved and got to where they are today. Also if you own an old four-wheeler, this autoguide on cars running on carburetors would surely help you understand the mechanism of your car's engine.

In order to optimize engine performance, engineers ensure that sufficient air is mixed with gasoline so that all of the gas burns during combustion. A mixture where all the fuel is burned is known as a Stoichiometric mixture. The lack of air results into low fuel efficiency and black smote exit from the tailpipe. On the other hand, the increase in air results into a decline of power and increase in heat. The optimum ratio of air to fuel for a normal combustion engine is around 14.7 pounds for every pound of gasoline.

In the late nineties, beginning of the automotive world, the carburetor was a mechanism used for mixing air with gasoline. Originating from the French word “carbure,” that refers to “carbide”, the Carburetor is a mechanical device and was used until the early 1990s. The 1991 Jeep Grand Wagoneer was the last American production vehicle to feature carburetor.  Carburetor is basically a tube through which filtered air flows from the automobile’s air intake. The venturi in the tube creates vacuum. The narrowing or a venturi has a small hole, named as jet, which deliver fuel via the float chamber. The float chamber is filled with fuel that is set by a float, while the vacuum created in the venturi draws in fuel from the chamber. The fuel in the chamber is at ambient pressure. The faster the air enter the carburetor throat, lower the pressure in the narrowing.

The throttle valve at the downstream of the jet opens up when the accelerator pedal is in works. This throttle valve manages the amount of air entering the carburetor. If the gas pedal pushes all the way down, the throttle valve opens fully. This allows air to flow faster through the carburetor, which creates a bigger vacuum in the narrowing. It leads to an increase in the fuel into the engine that creates more power. At idle situations, the throttle valve is fully shut. However, the system has an idling jet that bypasses the throttle valve and sends some fuel and air into the engine. The engine would shut, without an idling jet, if the throttle is not activated by the driver during idle. The carburetor also has the choke, which offers a rich fuel mixture at start up.

Latest Blog Articles

Blog Categories