What is Carburetor, Types of Carburetor, Function, Parts, Advantages, Application

What is Carburetor, Types of Carburetor, Function, Parts, Advantages, Application, in the last article we talk about SI and CI Engine Differences.

What is Carburetor?

A carburetor is a device that mixes fuel and air in the proper ratio for combustion in an internal combustion engine. It uses a venturi to create a low-pressure area that sucks fuel into the air stream, where it is mixed with air and then sent to the engine’s cylinders. Carburetors were widely used in vehicles before the advent of electronic fuel injection systems, but have since been largely replaced by EFI in modern cars.

Types of Carburetor?

here are several types of carburetors, including:

1. Single Barrel Carburetor: The simplest type of carburetor, it has one barrel or venturi and is typically found on small engines like lawn mowers and chainsaws.
2. Two-Barrel Carburetor: This type of carburetor has two barrels or venturis and is typically found on small and medium-sized engines.
3. Four-Barrel Carburetor: This type of carburetor has four barrels or venturis and is typically found on larger engines like those in automobiles and trucks.
4. Variable Venturi Carburetor (VVC) : This carburetor, also known as the variable jet carburetor, uses a variable air bleed system to adjust the air-fuel mixture.
5. Progressive Carburetor: This type of carburetor has a second barrel that begins to open as the throttle is opened further, providing a richer fuel mixture at high speeds.
6. Constant Velocity Carburetor (CV): This type of carburetor uses a vacuum operated slide to control the air/fuel mixture. It is commonly used on motorcycles and scooters.
7. Rotary carburetor : This type of carburetor uses a rotor to mix the fuel and air, rather than a venturi. They are most commonly used on two-stroke engines.

Function of Carburetor?

The main function of a carburetor is to mix fuel and air in the proper ratio for combustion in an internal combustion engine. The carburetor uses a venturi, which is a narrowing in the carburetor’s throat, to create a low-pressure area. As air flows through the venturi, it creates suction that pulls fuel from the carburetor’s float bowl through a jet and into the air stream. The fuel is then mixed with the incoming air in the carburetor’s mixing chamber.

The carburetor also includes a throttle valve that controls the amount of air that enters the engine, and a choke valve that regulates the amount of fuel that enters the engine during cold starts. Additionally, many carburetors include a mechanism for adjusting the air-fuel mixture, such as a mixture screw or a set of air jets.

The carburetor also has a float chamber, which is used to store fuel and maintain a constant level of fuel in the carburetor. It also includes a float, which acts as a buoyancy device and controls the fuel flow by opening and closing the needle valve.

In summary, the carburetor’s main functions include:

• Mixing fuel and air in the proper ratio for combustion
• Creating suction to pull fuel from the float bowl into the air stream
• Regulating the amount of fuel and air that enters the engine
• Adjusting the air-fuel mixture
• Maintaining a constant level of fuel in the carburetor.

What are Main Parts of Carburetor?

The main parts of a carburetor include:

1. Venturi: This is a constriction in the carburetor’s throat that creates a low-pressure area, which sucks fuel into the air stream.
2. Throttle valve: This valve controls the amount of air that enters the engine. It is connected to the accelerator pedal in a vehicle and is used to control the engine speed.
3. Choke valve: This valve regulates the amount of fuel that enters the engine during cold starts.
4. Float chamber: This is where fuel is stored and a constant level is maintained by the float, which acts as a buoyancy device and controls the fuel flow by opening and closing the needle valve.
5. Jets: These are small openings that control the flow of fuel into the carburetor. They can be adjusted to fine-tune the air-fuel mixture.
6. Air filter: This is a device that removes dirt and other particles from the incoming air to protect the engine from damage.
7. Throttle linkage: This connects the throttle valve to the accelerator pedal or other control mechanism.
8. Fuel inlet: This is where fuel enters the carburetor from the fuel tank.
9. Fuel outlet: This is where the mixed fuel and air exits the carburetor and enters the engine’s intake manifold.
10. Fuel pump: In some carburetor designs, a fuel pump is used to supply the carburetor with fuel from the fuel tank.
11. Accelerator pump: This is a small pump that delivers a shot of fuel when the accelerator is depressed quickly, such as during sudden acceleration. This helps to prevent hesitation or stalling.
12. Idle mixture screw: This is a screw that allows the user to adjust the air-fuel mixture at idle.
13. Vacuum ports: These are small openings that are connected to the engine’s intake manifold, allowing the carburetor to be influenced by the engine’s vacuum.
14. Float: This is a device that maintains a constant level of fuel in the carburetor.
15. Needle valve: This valve controls the flow of fuel into the carburetor and is controlled by the float.

Some carburetors might not have all the parts listed above, but they generally have most of them.

Advantages of Carburetor Over Fuel Injection in Car Engine?

Carburetors have a number of advantages over fuel injection systems in car engines, including:

1. Simplicity: Carburetors are relatively simple devices compared to fuel injection systems. They have fewer parts and are less complex to repair or replace.
2. Cost: Carburetors are generally less expensive than fuel injection systems, both in terms of initial cost and maintenance.
3. Cold weather starting: Carburetors are better suited for cold weather starting than fuel injection systems. They can provide the necessary fuel to start the engine in cold weather conditions.
4. Reliability: Carburetors are more reliable than fuel injection systems, which can be affected by a variety of issues such as clogging, leaks, and electrical problems.
5. Tuning: Carburetors are more flexible when it comes to tuning the engine. They allow for easy adjustments to the air-fuel mixture, which can help improve performance and efficiency.
6. Fuel economy: Carburetors have been known to have better fuel economy than their electronic fuel injection counterparts, especially in older cars.

It is worth noting that carburetors are not as efficient as electronic fuel injection systems, and they are less precise in the fuel-air mix they provide to the engine. Also, carburetors emit more pollutants, as they are not able to precisely control the fuel-air mixture. This is one of the reasons why carburetors are less common in modern cars.

Carburetors are commonly used in a variety of applications, including:

1. Automobiles: Carburetors were widely used in automobiles before the advent of electronic fuel injection systems. They are still used in some older vehicles and in some low-cost car models.
2. Small engines: Carburetors are commonly used in small engines, such as those found in lawn mowers, chainsaws, and other outdoor power equipment.
3. Motorcycles and scooters: Carburetors are still commonly used in motorcycles and scooters, particularly in smaller models and older models.
4. Marine engines: Carburetors are used in some marine engines, such as those found in outboard motors and personal watercraft.
5. Industrial and agricultural machinery: Carburetors are used in a variety of industrial and agricultural machinery, including generators, pumps, and tractors.
6. Recreational vehicles: Carburetors are also used in recreational vehicles such as go-karts, snowmobiles, and all-terrain vehicles.
7. Two-stroke engines: Carburetors are commonly used in two-stroke engines, as they provide a simple, reliable and efficient way to mix fuel and air.
8. Racing vehicles: Some racing vehicles, especially older ones, use carburetors, as they are more easily adjustable than fuel injection systems.

Overall, carburetors have been used in a wide range of applications, but their use has decreased over the years due to the increasing use of electronic fuel injection systems in automobiles and other vehicles.

Why is a Carburetor not Used in Diesel Engines?

A carburetor is not used in diesel engines because diesel fuel is injected directly into the combustion chamber. Carburetors are used to mix air and fuel before they enter the combustion chamber in gasoline engines, but diesel engines do not require this step because the high compression ratio in the cylinder causes the fuel to ignite spontaneously when it is injected. This is known as compression ignition.