Carter Carburetor was founded by William Carter for four-cylinder engine jeeps. The Carter Carburetor is a downdraft model. It has several jets, a plain tube, and only one adjustment for the engine’s idle or low-speed operation. Well, in this reading, we’ll explore what a Carter carburetor is, its functions, its construction, its diagram, and how it works.
Let’s begin!
Learn about Carburetor with this detailed guide!
What is a Carter carburetor?
The automobile industry has benefited greatly from Carter carburetors. The Carter Carburetor was renowned for its dependable performance and inventive designs. The business made a substantial contribution to the creation of several carburetor types, such as the sidedraft and downdraft designs. Carter Carburetor strengthened its position as a key participant in the automobile industry by providing carburetors for military vehicles during World War II.
In 1909, William Carter created the Carter Carburetor in St. Louis, Missouri. The firm first manufactured carburetors for a variety of sectors, but it soon discovered a niche in the automotive industry. Over the years, Carter Carburetor rose to prominence as a carburetor manufacturer, supplying American Motors Corporation (AMC), Ford, and Chrysler, among other automakers.
Just as earlier stated, A down-draft carburettor is a Carter carburetor. Fuel or petrol enters the chamber of a Carter carburettor, while air enters through the choke valve, which is placed at the top.
During normal engine operation, the choke valve remains open. It was started by William Carter, who was running a thriving cycling business at the time and began experimenting with vehicle carburetors. His initial carburetor, made of cast brass, could meter and distribute fuel more precisely than several competitors.
You should also learn about The Best Carburetor Cleaner with this detailed guide!
Construction & Working Principle
The gasoline is injected into the float chamber. During normal operation, air enters the carburetor from the top, and the choke valve in the channel remains open. There are three vents in this carburetor. The principal venturi, which is the smallest, is located above the fuel level in the float chamber.
Other than that, two ventures are located below the fuel level, and one is located below the other. The primary venturi’s suction is sufficient to extract petrol at very low speeds. The nozzle enters the primary venturi at an angle, atomizing the fuel and sending it upward against the air stream. The mixture from the primary venturi enters the secondary venturi, which is encircled by an air stream, and eventually flows to the final venturi.
The fresh air supply insulates the stream from the second venturi once again in the main venturi. The mixture is atomized when it enters the engine. Multiple ventures allow for greater mixture formation at low speeds, resulting in stable and smooth functioning at both low and high speeds.
Diagram
Operations of a Carter Carburetor
Engine starting circuit
A richer mixture must be delivered when the engine is starting. The suction formed by the piston during engine startup is applied to the nozzle, allowing the right amount of gasoline to be delivered. The choke valve also reduces the amount of air available.
To ensure that the proper amount of the richer mixture is prepared and introduced into the engine cylinder, the engine can start smoothly. When the engine begins, the spring-loaded choke valve opens to allow the proper amount of air to enter during the warm-up period.
Idle and Low low-speed (cruising) circuit
The richer mixture is necessary for tiny quantities for idle speed. The throttle valve is slightly open in this operating condition. In order for the suction caused by the piston’s downward movement to be applied to the optimal port.
The idle/slow-speed jet provides a rich mixture in this way. The idle adjustment screw can manage the air-fuel ratio. The throttle can be opened wider for a low-speed operation to keep the engine running smoothly above idle.
Acceleration of Engine
As illustrated in the diagram above, there is an acceleration pump system. This will aid in the acceleration of the engine by delivering additional fuel via a jet at the direct throat. The non-return intake check valve and the outlet check valve, as well as a plunger and a spring-operated accelerator pedal, make up this acceleration pump.
When we press the accelerator pedal, a small amount of gasoline is forced into the throat via the non-return inlet check valve, the outlet check valve, and the jet, as illustrated in the diagram above. When you let go of the pedal, some gasoline will be sucked from the float chamber.
Benefits of Carter Carburetor
- Reliable Fuel-Air Mixing – Carter carburetors are known for delivering a precise mixture of fuel and air, which ensures efficient combustion and smooth engine performance.
- Simplicity in Design – Their relatively simple mechanical design makes them easier to understand, troubleshoot, and rebuild compared to modern electronic systems.
- Wide Compatibility – Carter carburetors have been used in a wide range of vehicles, from classic cars to industrial engines, making them a popular choice in vintage car restoration projects.
- Durability – Built with robust materials, Carter carburetors are known for their long lifespan and resistance to wear, even under tough engine conditions.
- Manual Tuning Capability – Unlike modern fuel injection systems, Carter carburetors can be manually adjusted to suit different driving conditions or engine modifications.
- Cost-Effective Repairs – Parts for Carter carburetors are widely available, and repairs can often be done inexpensively without the need for advanced diagnostic equipment.
- Good Performance at Low Speeds – Many Carter models perform particularly well at low speeds and idle conditions, which is valuable for daily driving or low-RPM applications.
Conclusion
Carter carburetors have earned a reputation for their simplicity, reliability, and ease of maintenance. While they may not match the precision of modern fuel injection systems, they remain a valuable component in classic vehicles and restoration projects. Their ability to be tuned manually and their strong aftermarket support continue to make them a practical and cost-effective choice for many enthusiasts and mechanics.
FAQs About Carter Carburetors
Who makes Carter carburetors today?
Carter carburetors were originally produced by the Carter Carburetor Company, but now aftermarket and rebuilt units are supplied by various automotive part manufacturers.
Are Carter carburetors still good for modern engines?
While they are reliable, Carter carburetors are better suited for older engines. Modern engines typically rely on fuel injection systems for better efficiency and emissions control.
How do I know which Carter carburetor I have?
Most Carter carburetors have a tag or stamping with a model number that can be used to identify the unit. Reference guides and catalogs can help decode this number.
Can Carter carburetors be rebuilt?
Yes, they are very rebuildable. Rebuild kits are available for most models, and their mechanical design makes them easier to service than electronic systems.
What vehicles used Carter carburetors?
Carter carburetors were widely used in American cars like Dodge, Chrysler, Jeep, Ford, GM, and AMC vehicles from the early 1900s through the 1980s.
Are Carter and Rochester carburetors the same?
No. Carter and Rochester are different brands with distinct designs. Each has its own strengths and applications, although both were popular in classic American vehicles.