Carburetor
Overview
 
A carburetor carburettor, or carburetter (Commonwealth spelling
American and British English spelling differences
One of the ways in which American English and British English differ is in spelling.-Historical origins:In the early 18th century, English spelling was not standardized. Differences became noticeable after the publishing of influential dictionaries...

) is a device that blends air
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...

 and fuel
Fuel
Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...

 for an internal combustion engine
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...

. It is sometimes shortened to carb in North America and the United Kingdom.
The word carburetor comes from the French carbure meaning "carbide
Carbide
In chemistry, a carbide is a compound composed of carbon and a less electronegative element. Carbides can be generally classified by chemical bonding type as follows: salt-like, covalent compounds, interstitial compounds, and "intermediate" transition metal carbides...

". Carburer means to combine with carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...

. In fuel chemistry, the term has the more specific meaning of increasing the carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...

 (and therefore energy) content of a fuel by mixing it with a volatile hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

.
A carburetor was among the early patents by Karl Benz
Karl Benz
Karl Friedrich Benz, was a German engine designer and car engineer, generally regarded as the inventor of the gasoline-powered car, and together with Bertha Benz pioneering founder of the automobile manufacturer Mercedes-Benz...

 as he developed internal combustion engines and their components.
Encyclopedia
A carburetor carburettor, or carburetter (Commonwealth spelling
American and British English spelling differences
One of the ways in which American English and British English differ is in spelling.-Historical origins:In the early 18th century, English spelling was not standardized. Differences became noticeable after the publishing of influential dictionaries...

) is a device that blends air
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...

 and fuel
Fuel
Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...

 for an internal combustion engine
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...

. It is sometimes shortened to carb in North America and the United Kingdom.

Word origin

The word carburetor comes from the French carbure meaning "carbide
Carbide
In chemistry, a carbide is a compound composed of carbon and a less electronegative element. Carbides can be generally classified by chemical bonding type as follows: salt-like, covalent compounds, interstitial compounds, and "intermediate" transition metal carbides...

". Carburer means to combine with carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...

. In fuel chemistry, the term has the more specific meaning of increasing the carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...

 (and therefore energy) content of a fuel by mixing it with a volatile hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

.

History and development

A carburetor was among the early patents by Karl Benz
Karl Benz
Karl Friedrich Benz, was a German engine designer and car engineer, generally regarded as the inventor of the gasoline-powered car, and together with Bertha Benz pioneering founder of the automobile manufacturer Mercedes-Benz...

 as he developed internal combustion engines and their components. The Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

n automobile
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

 pioneer Siegfried Marcus
Siegfried Marcus
Siegfried Samuel Marcus was a German-born Austrian inventor and automobile pioneer.Marcus was born in Malchin in Mecklenburg-Schwerin. He moved to Vienna, the capital of the Austrian Empire, in 1852....

 invented the “rotating brush carburettor”. This was further improved by the Hungarian
Hungary
Hungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...

 engineer
Engineer
An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...

s János Csonka
János Csonka
Hungarian János Csonka was the co-inventor of the carburetor with Donát Bánki, patented on February 13, 1893.- Life :...

 and Donát Bánki
Donát Bánki
Donát Bánki was a Hungarian mechanical engineer, inventor of the carburetor, togetherwith János Csonka, in 1893, as the Bánki-Csonka engine....

 in 1893.

Frederick William Lanchester of Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...

, England, experimented with the wick carburetor in cars. In 1896, Frederick and his brother built the first gasoline driven car in England, a single cylinder 5 hp internal combustion engine with chain drive. Unhappy with the performance and power, they re-built the engine the next year into a two cylinder horizontally opposed version using his new wick carburetor design.

In 1885, Wilhelm Maybach
Wilhelm Maybach
Wilhelm Maybach was an early German engine designer and industrialist. During the 1890s he was hailed in France, then the world centre for car production, as the "King of constructors"....

 and Gottlieb Daimler
Gottlieb Daimler
Gottlieb Daimler was an engineer, industrial designer and industrialist born in Schorndorf , in what is now Germany. He was a pioneer of internal-combustion engines and automobile development...

 developed a carburetor for their engine based on the atomizer nozzle
Atomizer nozzle
An atomizer nozzle is an aspirator nozzle for producing a fine spray of a liquid based on the Venturi effect.-Principle of operation :When a gas is injected under pressure through a tube with a decreasing section, it speeds up, generating a pressure drop at the narrowest point .The reduced...

.

Carburetors were the usual fuel delivery method for most U.S. made gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...

-fueled engines up until the late 1980s, when fuel injection
Fuel injection
Fuel injection is a system for admitting fuel into an internal combustion engine. It has become the primary fuel delivery system used in automotive petrol engines, having almost completely replaced carburetors in the late 1980s....

 became the preferred method of automotive fuel delivery. In the U.S. market, the last carbureted cars were:
  • 1990 (General public) : Oldsmobile Custom Cruiser
    Oldsmobile Custom Cruiser
    The Oldsmobile Custom Cruiser is large rear-wheel drive station wagon which was produced by Oldsmobile from 1971 to 1992. The Custom Cruiser used the same platform as the Buick, Chevrolet and Pontiac full-size wagons...

    , Buick Estate Wagon
    Buick Estate
    Buick used the Estate name on their full-size station wagons.The first Buick Estate used a wooden body and was offered on the 1940 Super model. It was available on Buick's B-body Special series in 1941 and 1942, and later on Buick's larger C-body in the 1946-53 model years...

  • 1991 (Police) : Ford Crown Victoria
    Ford Crown Victoria
    -1992–1994:Released in March 1991 as an early 1992 model, the Crown Victoria sedan was completely redesigned with a rounder, eight-window roofline . The redesign reduced the coefficient of drag from 0.42 to 0.34; the suspension setup was also heavily revised...

     Police Interceptor
    Police car
    A police car is a ground vehicle used by police, to assist with their duties in patrolling and responding to incidents. Typical uses of a police car include transportation for officers to reach the scene of an incident quickly, to transport criminal suspects, or to patrol an area, while providing a...

     with the 351 cu in (5.8 l) engine.
  • 1991 (SUV) : Jeep Grand Wagoneer
    Jeep Wagoneer
    The Jeep Wagoneer was an early sport utility vehicle and the first luxury 4x4, produced under varying marques from 1963 to 1991. It was noteworthy for being in production for more than 28 years with only minor mechanical changes...

     with the AMC
    AMC V8 engine
    American Motors Corporation produced a series of widely-used V8 engines from the mid-1950s before being absorbed into Chrysler in 1987. Chrysler kept the AMC V8 in production until 1991 for the Jeep Grand Wagoneer....

     360 engine.
  • 1994 (Light truck) : Isuzu
    Isuzu
    , is a Japanese car, commercial vehicle and heavy truck manufacturing company, headquartered in Tokyo. In 2005, Isuzu became the world's largest manufacturer of medium to heavy duty trucks. It has assembly and manufacturing plants in the Japanese city of Fujisawa, as well as in the prefectures...


In Australia, some cars continued to use carburetors well into the 1990s; these included the Honda Civic until 1993, Daihatsu Charade until 1997, the Suzuki Swift until its end in 1999, as well as the Ford Laser (1994), Mazda 323 sedan (1996), and Mitsubishi Magna sedan (1996). Low-cost commercial vans and 4WDs in Australia continued with carburetors even into the 2000s, the last being the Mitsubishi Express van in 2003. Elsewhere, certain Lada
Lada
Lada is a trademark of AvtoVAZ, a Russian car manufacturer in Tolyatti, Samara Oblast. All AvtoVAZ vehicles are currently sold under the Lada brand, though this was not always so; Lada was originally AvtoVAZ's export brand for models it sold under the Zhiguli name in the domestic Soviet market...

 cars used carburetors until 2006. A majority of motorcycle
Motorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...

s still use carburetors due to lower cost and throttle response problems with early injection setups, but as of 2005 many new models are now being introduced with fuel injection. Carburetors are still found in small engines and in older or specialized automobile
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

s, such as those designed for stock car racing
Stock car racing
Stock car racing is a form of automobile racing found mainly in the United States, Canada, New Zealand, Great Britain, Brazil and Argentina. Traditionally, races are run on oval tracks measuring approximately in length...

.

Principles

The carburetor works on Bernoulli's principle
Bernoulli's principle
In fluid dynamics, Bernoulli's principle states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy...

: the faster air moves, the lower its static pressure
Static pressure
In fluid mechanics the term static pressure has several uses:* In the design and operation of aircraft, static pressure is the air pressure in the aircraft’s static pressure system....

, and the higher its dynamic pressure. The throttle
Throttle
A throttle is the mechanism by which the flow of a fluid is managed by constriction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases , but usually decreased. The term throttle has come to refer, informally and incorrectly, to any mechanism by which...

 (accelerator) linkage does not directly control the flow of liquid fuel. Instead, it actuates carburetor mechanisms which meter the flow of air being pulled into the engine. The speed of this flow, and therefore its pressure, determines the amount of fuel drawn into the airstream.

When carburetors are used in aircraft with piston engines, special designs and features
Miss Shilling's orifice
Miss Shilling's Orifice was a very simple technical device made to counter engine cut-out in early Spitfire and Hurricane fighter aeroplanes during the Battle of Britain...

 are needed to prevent fuel starvation during inverted flight. Later engines used an early form of fuel injection known as a pressure carburetor
Pressure carburetor
A pressure carburetor is a type of fuel metering system manufactured by the Bendix Corporation for piston aircraft engines, starting in the 1940s. It is recognized as an early type of throttle-body fuel injection and was developed to prevent fuel starvation during inverted flight.-Concept:Most...

.

Most production carbureted (as opposed to fuel-injected
Fuel injection
Fuel injection is a system for admitting fuel into an internal combustion engine. It has become the primary fuel delivery system used in automotive petrol engines, having almost completely replaced carburetors in the late 1980s....

) engines have a single carburetor and a matching intake manifold that divides and transports the air fuel mixture to the intake valves, though some engines (like motorcycle engines) use multiple carburetors on split heads. Multiple carburetor engines were also common enhancements for modifying engines in the USA from the 1950s to mid-1960s, as well as during the following decade of high-performance muscle car
Muscle car
Muscle car is a term used to refer to a variety of high-performance automobiles. The Merriam-Webster dictionary defines muscle cars as "any of a group of American-made 2-door sports coupes with powerful engines designed for high-performance driving." Usually, a large V8 engine is fitted in a...

s fueling different chambers of the engine's intake manifold.

Older engines used updraft carburetors, where the air enters from below the carburetor and exits through the top. This had the advantage of never "flooding" the engine
Flooded engine
A flooded engine is an internal combustion engine that has been fed an excessively rich air-fuel mixture that cannot be ignited. This is caused by the mixture exceeding the upper explosive limit for the particular fuel. An engine in this condition will not start until the excessively rich mixture...

, as any liquid fuel droplets would fall out of the carburetor instead of into the intake manifold; it also lent itself to use of an oil
Motor oil
Motor oil or engine oil is an oil used for lubrication of various internal combustion engines. The main function is to lubricate moving parts; it also cleans, inhibits corrosion, improves sealing, and cools the engine by carrying heat away from moving parts.Motor oils are derived from...

 bath air cleaner, where a pool of oil below a mesh element below the carburetor is sucked up into the mesh and the air is drawn through the oil-covered mesh; this was an effective system in a time when paper air filter
Air filter
A particulate air filter is a device composed of fibrous materials which removes solid particulates such as dust, pollen, mold, and bacteria from the air. A chemical air filter consists of an absorbent or catalyst for the removal of airborne molecular contaminants such as volatile organic compounds...

s did not exist.

Beginning in the late 1930s, downdraft carburetors were the most popular type for automotive use in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. In Europe, the sidedraft carburetors replaced downdraft as free space in the engine bay decreased and the use of the SU-type carburetor (and similar units from other manufacturers) increased. Some small propeller-driven aircraft engines still use the updraft carburetor design.

Outboard motor
Outboard motor
An outboard motor is a propulsion system for boats, consisting of a self-contained unit that includes engine, gearbox and propeller or jet drive, designed to be affixed to the outside of the transom and are the most common motorized method of propelling small watercraft...

 carburetors are typically sidedraft, because they must be stacked one on top of the other in order to feed the cylinders in a vertically oriented cylinder block.
The main disadvantage of basing a carburetor's operation on Bernoulli's principle is that, being a fluid dynamic device, the pressure reduction in a venturi tends to be proportional to the square of the intake air speed. The fuel jets are much smaller and limited mainly by viscosity, so that the fuel flow tends to be proportional to the pressure difference. So jets sized for full power tend to starve the engine at lower speed and part throttle. Most commonly this has been corrected by using multiple jets. In SU and other movable jet carburetors, it was corrected by varying the jet size. For cold starting, a different principle was used, in multi-jet carburetors. A flow resisting valve called a choke, similar to the throttle valve, was placed upstream of the main jet to reduce the intake pressure and suck additional fuel out of the jets.

Operation

  • Fixed-venturi
    Venturi effect
    The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section of pipe. The Venturi effect is named after Giovanni Battista Venturi , an Italian physicist.-Background:...

    , in which the varying air velocity in the venturi alters the fuel flow; this architecture is employed in most carburetors found on cars.
  • Variable-venturi, in which the fuel jet opening is varied by the slide (which simultaneously alters air flow). In "constant depression" carburetors, this is done by a vacuum operated piston connected to a tapered needle which slides inside the fuel jet. A simpler version exists, most commonly found on small motorcycles and dirt bikes, where the slide and needle is directly controlled by the throttle position. The most common variable venturi (constant depression) type carburetor is the sidedraft SU carburetor and similar models from Hitachi, Zenith-Stromberg and other makers. The UK location of the SU and Zenith-Stromberg companies helped these carburetors rise to a position of domination in the UK car market, though such carburetors were also very widely used on Volvo
    Volvo
    AB Volvo is a Swedish builder of commercial vehicles, including trucks, buses and construction equipment. Volvo also supplies marine and industrial drive systems, aerospace components and financial services...

    s and other non-UK makes. Other similar designs have been used on some European and a few Japanese automobiles. These carburetors are also referred to as "constant velocity" or "constant vacuum" carburetors. An interesting variation was Ford's VV (Variable Venturi) carburetor, which was essentially a fixed venturi carburetor with one side of the venturi hinged and movable to give a narrow throat at low rpm and a wider throat at high rpm. This was designed to provide good mixing and airflow over a range of engine speeds, though the VV carburetor proved problematic in service.

Under all engine operating conditions, the carburetor must:
  • Measure the airflow of the engine
  • Deliver the correct amount of fuel to keep the fuel/air mixture in the proper range (adjusting for factors such as temperature)
  • Mix the two finely and evenly


This job would be simple if air and gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...

 (petrol) were ideal fluids; in practice, however, their deviations from ideal behavior due to viscosity, fluid drag, inertia, etc. require a great deal of complexity to compensate for exceptionally high or low engine speeds. A carburetor must provide the proper fuel/air mixture across a wide range of ambient temperatures, atmospheric pressures, engine speeds and loads, and centrifugal force
Centrifugal force
Centrifugal force can generally be any force directed outward relative to some origin. More particularly, in classical mechanics, the centrifugal force is an outward force which arises when describing the motion of objects in a rotating reference frame...

s:
  • Cold start
  • Hot start
  • Idling or slow-running
  • Acceleration
  • High speed / high power at full throttle
  • Cruising at part throttle (light load)


In addition, modern carburetors are required to do this while maintaining low rates of exhaust emissions
Automobile emissions control
Vehicle emissions control is the study and practice of reducing the motor vehicle emissions -- emissions produced by motor vehicles, especially internal combustion engines....

.

To function correctly under all these conditions, most carburetors contain a complex set of mechanisms to support several different operating modes, called circuits.

Basics

A carburetor basically consists of an open pipe through which the air passes into the inlet manifold
Inlet manifold
In automotive engineering, an inlet manifold or intake manifold is the part of an engine that supplies the fuel/air mixture to the cylinders...

 of the engine. The pipe is in the form of a venturi: it narrows in section and then widens again, causing the airflow to increase in speed in the narrowest part. Below the venturi is a butterfly valve
Butterfly valve
A butterfly valve is a valve which can be used for isolating or regulating flow. The closing mechanism takes the form of a disk. Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves are generally favored because they are lower in cost to other valve...

 called the throttle valve — a rotating disc that can be turned end-on to the airflow, so as to hardly restrict the flow at all, or can be rotated so that it (almost) completely blocks the flow of air. This valve controls the flow of air through the carburetor throat and thus the quantity of air/fuel mixture the system will deliver, thereby regulating engine power and speed. The throttle is connected, usually through a cable
Bowden cable
A Bowden cable is a type of flexible cable used to transmit mechanical force or energy by the movement of an inner cable relative to a hollow outer cable housing...

 or a mechanical linkage of rods and joints or rarely by pneumatic link
Hillman Imp
The Hillman Imp is a compact, rear-engined saloon car that was manufactured under the Hillman marque by the Rootes Group from 1963 to 1976...

, to the accelerator pedal
Automobile pedal
An automobile may have two to four foot pedals. The arrangement is the same for both right- and left-hand traffic. From left to right:* normally operated by the left foot:**clutch pedal, not in the case of automatic transmission...

 on a car or the equivalent control on other vehicles or equipment.

Fuel is introduced into the air stream through small holes at the narrowest part of the venturi and at other places where pressure will be lowered when not running on full throttle. Fuel flow is adjusted by means of precisely calibrated orifices, referred to as jets, in the fuel path.

Off-idle circuit

As the throttle is opened up slightly from the fully closed position, the throttle plate uncovers additional fuel delivery holes behind the throttle plate where there is a low pressure area created by the throttle plate blocking air flow; these allow more fuel to flow as well as compensating for the reduced vacuum that occurs when the throttle is opened, thus smoothing the transition to metering fuel flow through the regular open throttle circuit.

Main open-throttle circuit

As the throttle is progressively opened, the manifold vacuum is lessened since there is less restriction on the airflow, reducing the flow through the idle and off-idle circuits. This is where the venturi
Venturi effect
The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section of pipe. The Venturi effect is named after Giovanni Battista Venturi , an Italian physicist.-Background:...

 shape of the carburetor throat comes into play, due to Bernoulli's principle
Bernoulli's principle
In fluid dynamics, Bernoulli's principle states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy...

 (i.e., as the velocity increases, pressure falls). The venturi raises the air velocity, and this high speed and thus low pressure sucks fuel into the airstream through a nozzle or nozzles located in the center of the venturi. Sometimes one or more additional booster venturis are placed coaxially within the primary venturi to increase the effect.

As the throttle is closed, the airflow through the venturi drops until the lowered pressure is insufficient to maintain this fuel flow, and the idle circuit takes over again, as described above.

Bernoulli's principle, which is a function of the velocity of the fluid, is a dominant effect for large openings and large flow rates, but since fluid flow at small scales and low speeds (low Reynolds number) is dominated by viscosity
Viscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...

, Bernoulli's principle is ineffective at idle or slow running and in the very small carburetors of the smallest model engines. Small model engines have flow restrictions ahead of the jets to reduce the pressure enough to suck the fuel into the air flow. Similarly the idle and slow running jets of large carburetors are placed after the throttle valve where the pressure is reduced partly by viscous drag, rather than by Bernoulli's principle. The most common rich mixture device for starting cold engines was the choke, which works on the same principle.

Power valve

For open throttle operation a richer mixture will produce more power, prevent pre-ignition detonation
Engine knocking
Knocking in spark-ignition internal combustion engines occurs when combustion of the air/fuel mixture in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front.The...

, and keep the engine cooler. This is usually addressed with a spring-loaded "power valve", which is held shut by engine vacuum. As the throttle opens up, the vacuum decreases and the spring opens the valve to let more fuel into the main circuit. On two-stroke engines, the operation of the power valve is the reverse of normal — it is normally "on" and at a set rpm it is turned "off". It is activated at high rpm to extend the engine's rev range, capitalizing on a two-stroke's tendency to rev higher momentarily when the mixture is lean.

Alternative to employing a power valve, the carburetor may utilize a metering rod or step-up rod system to enrich the fuel mixture under high-demand conditions. Such systems were originated by Carter Carburetor in the 1950s for the primary two venturis of their four barrel carburetors, and step-up rods were widely used on most 1-, 2-, and 4-barrel Carter carburetors through the end of production in the 1980s. The step-up rods are tapered at the bottom end, which extends into the main metering jets. The tops of the rods are connected to a vacuum piston and/or a mechanical linkage which lifts the rods out of the main jets when the throttle is opened (mechanical linkage) and/or when manifold vacuum drops (vacuum piston). When the step-up rod is lowered into the main jet, it restricts the fuel flow. When the step-up rod is raised out of the jet, more fuel can flow through it. In this manner, the amount of fuel delivered is tailored to the transient demands of the engine. Some 4-barrel carburetors use metering rods only on the primary two venturis, but some use them on both primary and secondary circuits, as in the Rochester Quadrajet.

Accelerator pump

Liquid gasoline, being denser than air, is slower than air to react to a force
Inertia
Inertia is the resistance of any physical object to a change in its state of motion or rest, or the tendency of an object to resist any change in its motion. It is proportional to an object's mass. The principle of inertia is one of the fundamental principles of classical physics which are used to...

 applied to it. When the throttle is rapidly opened, airflow through the carburetor increases immediately, faster than the fuel flow rate can increase. This transient oversupply of air causes a lean mixture, which makes the engine misfire (or "stumble")—an effect opposite what was demanded by opening the throttle. This is remedied by the use of a small piston
Piston pump
A piston pump is a type of positive displacement pump where the high-pressure seal reciprocates with the piston. Piston pumps can be used to move liquids or compress gases.-Types:* Axial piston pump* Radial piston pump...

 or diaphragm
Diaphragm pump
A diaphragm pump is a positive displacement pump that uses a combination of the reciprocating action of a rubber, thermoplastic or teflon diaphragm and suitable non-return check valves to pump a fluid...

 pump which, when actuated by the throttle linkage, forces a small amount of gasoline through a jet into the carburetor throat. This extra shot of fuel counteracts the transient lean condition on throttle tip-in. Most accelerator pumps are adjustable for volume and/or duration by some means. Eventually the seals around the moving parts of the pump wear such that pump output is reduced; this reduction of the accelerator pump shot causes stumbling under acceleration until the seals on the pump are renewed.

The accelerator pump is also used to prime the engine with fuel prior to a cold start. Excessive priming, like an improperly adjusted choke, can cause flooding
Flooded engine
A flooded engine is an internal combustion engine that has been fed an excessively rich air-fuel mixture that cannot be ignited. This is caused by the mixture exceeding the upper explosive limit for the particular fuel. An engine in this condition will not start until the excessively rich mixture...

. This is when too much fuel and not enough air are present to support combustion. For this reason, most carburetors are equipped with an unloader mechanism: The accelerator is held at wide open throttle while the engine is cranked, the unloader holds the choke open and admits extra air, and eventually the excess fuel is cleared out and the engine starts.

Choke

When the engine is cold, fuel vaporizes less readily and tends to condense on the walls of the intake manifold, starving the cylinders of fuel and making the engine difficult to start; thus, a richer mixture (more fuel to air) is required to start and run the engine until it warms up. A richer mixture is also easier to ignite.

To provide the extra fuel, a choke is typically used; this is a device that restricts the flow of air at the entrance to the carburetor, before the venturi. With this restriction in place, extra vacuum is developed in the carburetor barrel, which pulls extra fuel through the main metering system to supplement the fuel being pulled from the idle and off-idle circuits. This provides the rich mixture required to sustain operation at low engine temperatures.

In addition, the choke can be connected to a cam
Cam
A cam is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion or vice-versa. It is often a part of a rotating wheel or shaft that strikes a lever at one or more points on its circular path...

 (the fast idle cam) or other such device which prevents the throttle plate from closing fully while the choke is in operation. This causes the engine to idle at a higher speed. Fast idle serves as a way to help the engine warm up quickly, and give a more stable idle while cold by increasing airflow throughout the intake system which helps to better atomize the cold fuel.

In many carbureted cars, the choke is controlled by a cable connected to a pull-knob on the dashboard operated by the driver. In some carbureted cars it is automatically controlled by a thermostat
Thermostat
A thermostat is the component of a control system which regulates the temperature of a system so that the system's temperature is maintained near a desired setpoint temperature. The thermostat does this by switching heating or cooling devices on or off, or regulating the flow of a heat transfer...

 employing a bimetallic spring, which is exposed to engine heat, or to an electric heating element. This heat may be transferred to the choke thermostat via simple convection, via engine coolant, or via air heated by the exhaust. More recent designs use the engine heat only indirectly: A sensor detects engine heat and varies electrical
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

 current to a small heating element, which acts upon the bimetallic spring to control its tension, thereby controlling the choke. A choke unloader is a linkage arrangement that forces the choke open against its spring when the vehicle's accelerator is moved to the end of its travel. This provision allows a "flooded" engine to be cleared out so that it will start.

Some carburetors do not have a choke but instead use a mixture enrichment circuit, or enrichener. Typically used on small engines, notably motorcycles, enricheners work by opening a secondary fuel circuit below the throttle valves. This circuit works exactly like the idle circuit, and when engaged it simply supplies extra fuel when the throttle is closed.

Classic British motorcycles, with side-draft slide throttle carburetors, used another type of "cold start device", called a "tickler". This is simply a spring-loaded rod that, when depressed, manually pushes the float down and allows excess fuel to fill the float bowl and flood the intake tract. If the "tickler" is held down too long it also floods the outside of the carburetor and the crankcase below, and is therefore a fire hazard.

Other elements

The interactions between each circuit may also be affected by various mechanical or air pressure connections and also by temperature sensitive and electrical components. These are introduced for reasons such as response, fuel efficiency
Fuel efficiency
Fuel efficiency is a form of thermal efficiency, meaning the efficiency of a process that converts chemical potential energy contained in a carrier fuel into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is...

 or automobile emissions control
Automobile emissions control
Vehicle emissions control is the study and practice of reducing the motor vehicle emissions -- emissions produced by motor vehicles, especially internal combustion engines....

. Various air bleeds (often chosen from a precisely calibrated range, similarly to the jets) allow air into various portions of the fuel passages to enhance fuel delivery and vaporization. Extra refinements may be included in the carburetor/manifold combination, such as some form of heating to aid fuel vaporization such as an early fuel evaporator
Early fuel evaporator
The Early fuel evaporator is a device found in some internal combustion engines with carburetors. It can sometimes be referred to as an Electronic fuel evaporator. The device on a car, commonly referred to as an EFE heater is located between the throttle body of the carburetor and the intake...

.

Float chamber

To ensure a ready mixture, the carburetor has a "float chamber" (or "bowl") that contains a quantity of fuel at near-atmospheric pressure, ready for use. This reservoir is constantly replenished with fuel supplied by a fuel pump
Fuel pump
A fuel pump is a frequently essential component on a car or other internal combustion engined device. Many engines do not require any fuel pump at all, requiring only gravity to feed fuel from the fuel tank through a line or hose to the engine...

. The correct fuel level in the bowl is maintained by means of a float controlling an inlet valve
Valve
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...

, in a manner very similar to that employed in a cistern
Cistern
A cistern is a waterproof receptacle for holding liquids, usually water. Cisterns are often built to catch and store rainwater. Cisterns are distinguished from wells by their waterproof linings...

 (e.g. a toilet
Toilet
A toilet is a sanitation fixture used primarily for the disposal of human excrement, often found in a small room referred to as a toilet/bathroom/lavatory...

 tank). As fuel is used up, the float drops, opening the inlet valve and admitting fuel. As the fuel level rises, the float rises and closes the inlet valve. The level of fuel maintained in the float bowl can usually be adjusted, whether by a setscrew or by something crude such as bending the arm to which the float is connected. This is usually a critical adjustment, and the proper adjustment is indicated by lines inscribed into a window on the float bowl, or a measurement of how far the float hangs below the top of the carburetor when disassembled, or similar. Floats can be made of different materials, such as sheet brass
Brass
Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...

 soldered into a hollow shape, or of plastic; hollow floats can spring small leaks and plastic floats can eventually become porous and lose their flotation; in either case the float will fail to float, fuel level will be too high, and the engine will not run unless the float is replaced. The valve itself becomes worn on its sides by its motion in its "seat" and will eventually try to close at an angle, and thus fails to shut off the fuel completely; again, this will cause excessive fuel flow and poor engine operation. Conversely, as the fuel evaporates from the float bowl, it leaves sediment, residue, and varnishes behind, which clog the passages and can interfere with the float operation. This is particularly a problem in automobiles operated for only part of the year and left to stand with full float chambers for months at a time; commercial fuel stabilizer additives are available that reduce this problem.

Usually, special vent tubes allow air to escape from the chamber as it fills or enter as it empties, maintaining atmospheric pressure within the float chamber; these usually extend into the carburetor throat. Placement of these vent tubes can be somewhat critical to prevent fuel from sloshing out of them into the carburetor, and sometimes they are modified with longer tubing. Note that this leaves the fuel at atmospheric pressure, and therefore it cannot travel into a throat which has been pressurized by a supercharger
Supercharger
A supercharger is an air compressor used for forced induction of an internal combustion engine.The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine, which allows more fuel to be burned and more work to be done per cycle,...

 mounted upstream; in such cases, the entire carburetor must be contained in an airtight pressurized box to operate. This is not necessary in installations where the carburetor is mounted upstream of the supercharger, which is for this reason the more frequent system. However, this results in the supercharger being filled with compressed fuel/air mixture, with a strong tendency to explode should the engine backfire; this type of explosion is frequently seen in drag races, which for safety reasons now incorporate pressure releasing blow-off plates on the intake manifold, breakaway bolts holding the supercharger to the manifold, and shrapnel-catching ballistic nylon blankets surrounding the superchargers.

If the engine must be operated in any orientation (for example a chain saw), a float chamber cannot work. Instead, a diaphragm chamber is used. A flexible diaphragm forms one side of the fuel chamber and is arranged so that as fuel is drawn out into the engine the diaphragm is forced inward by ambient air pressure. The diaphragm is connected to the needle valve
Needle valve
A needle valve is a type of valve having a small port and a threaded, needle-shaped plunger. It allows precise regulation of flow, although it is generally only capable of relatively low flow rates.- Construction and operation :...

 and as it moves inward it opens the needle valve to admit more fuel, thus replenishing the fuel as it is consumed. As fuel is replenished the diaphragm moves out due to fuel pressure and a small spring, closing the needle valve. A balanced state is reached which creates a steady fuel reservoir level, which remains constant in any orientation.

Multiple carburetor barrels

While basic carburetors have only one venturi, many carburetors have more than one venturi, or "barrel". Two barrel and four barrel configurations are commonly used to accommodate the higher air flow rate with large engine displacement
Engine displacement
Engine displacement is the volume swept by all the pistons inside the cylinders of an internal combustion engine in a single movement from top dead centre to bottom dead centre . It is commonly specified in cubic centimeters , litres , or cubic inches...

. Multi-barrel carburetors can have non-identical primary and secondary barrel(s) of different sizes and calibrated to deliver different air/fuel mixtures; they can be actuated by the linkage or by engine vacuum in "progressive" fashion, so that the secondary barrels do not begin to open until the primaries are almost completely open. This is a desirable characteristic which maximizes airflow through the primary barrel(s) at most engine speeds, thereby maximizing the pressure "signal" from the venturis, but reduces the restriction in airflow at high speeds by adding cross-sectional area for greater airflow. These advantages may not be important in high-performance applications where part throttle operation is irrelevant, and the primaries and secondaries may all open at once, for simplicity and reliability; also, V-configuration engines, with two cylinder banks fed by a single carburetor, may be configured with two identical barrels, each supplying one cylinder bank. In the widely seen V8 and 4-barrel carburetor combination, there are often two primary and two secondary barrels.

The spread-bore 4-barrel carburetor, first released by Rochester in the 1965 model year as the "Quadrajet" has a much greater spread between the sizes of the primary and secondary throttle bores. The primaries in such a carburetor are quite small relative to conventional 4-barrel practice, while the secondaries are quite large. The small primaries aid low-speed fuel economy and drivability, while the large secondaries permit maximum performance when it is called for. To tailor airflow through the secondary venturis, each of the secondary throats has an air valve at the top. This is configured much like a choke plate, and is lightly spring-loaded into the closed position. The air valve opens progressively in response to engine speed and throttle opening, gradually allowing more air to flow through the secondary side of the carburetor. Typically, the air valve is linked to metering rods which are raised as the air valve opens, thereby adjusting secondary fuel flow.

Multiple carburetors can be mounted on a single engine, often with progressive linkages; two four-barrel carburetors (often referred to as "dual-quads") were frequently seen on high performance American V8s, and multiple two barrel carburetors are often now seen on very high performance engines. Large numbers of small carburetors have also been used (see photo), though this configuration can limit the maximum air flow through the engine due to the lack of a common plenum; with individual intake tracts, not all cylinders are drawing air at once as the engine's crankshaft rotates.

Carburetor adjustment

Too much fuel in the fuel-air mixture is referred to as too rich, and not enough fuel is too lean. The mixture is normally adjusted by one or more needle valve
Needle valve
A needle valve is a type of valve having a small port and a threaded, needle-shaped plunger. It allows precise regulation of flow, although it is generally only capable of relatively low flow rates.- Construction and operation :...

s on an automotive carburetor, or a pilot-operated lever on piston-engined aircraft (since mixture is air density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...

 (altitude) dependent). The (stoichiometric
Stoichiometry
Stoichiometry is a branch of chemistry that deals with the relative quantities of reactants and products in chemical reactions. In a balanced chemical reaction, the relations among quantities of reactants and products typically form a ratio of whole numbers...

) air to gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...

 ratio
Ratio
In mathematics, a ratio is a relationship between two numbers of the same kind , usually expressed as "a to b" or a:b, sometimes expressed arithmetically as a dimensionless quotient of the two which explicitly indicates how many times the first number contains the second In mathematics, a ratio is...

 is 14.7:1, meaning that for each weight unit of gasoline, 14.7 units of air will be consumed. Stoichiometric mixture are different for various fuels other than gasoline.

Ways to check carburetor mixture adjustment include: measuring the carbon monoxide
Carbon monoxide
Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...

, hydrocarbon, and oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

 content of the exhaust using a gas analyzer, or directly viewing the colour of the flame in the combustion chamber through a special glass-bodied spark plug sold under the name "Colortune"; the flame colour of stoichiometric burning is described as a "bunsen blue", turning to yellow if the mixture is rich and whitish-blue if too lean.

The mixture can also be judged by removing and scrutinizing the spark plugs. black
Black
Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light...

, dry, soot
Soot
Soot is a general term that refers to impure carbon particles resulting from the incomplete combustion of a hydrocarbon. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolyzed fuel particles such as cenospheres,...

y plugs indicate a mixture too rich; white
White
White is a color, the perception of which is evoked by light that stimulates all three types of color sensitive cone cells in the human eye in nearly equal amounts and with high brightness compared to the surroundings. A white visual stimulation will be void of hue and grayness.White light can be...

 to light gray plugs indicate a lean mixture. A proper mixture is indicated by brown
Brown
Brown is a color term, denoting a range of composite colors produced by a mixture of orange, red, rose, or yellow with black or gray. The term is from Old English brún, in origin for any dusky or dark shade of color....

ish-gray plugs.

In the 1980s, many American-market vehicles used special "feedback" carburetors that could change the base mixture in response to signals from an exhaust gas oxygen sensor
Oxygen sensor
An oxygen sensor, or lambda sensor, is an electronic device that measures the proportion of oxygen in the gas or liquid being analyzed. It was developed by the Robert Bosch GmbH company during the late 1960s under the supervision of Dr. Günter Bauman...

. These were mainly used because they were less expensive than fuel injection systems; they worked well enough to meet 1980s emissions requirements and were based on existing carburetor designs. Eventually, however, falling hardware prices and tighter emissions standards caused fuel injection
Fuel injection
Fuel injection is a system for admitting fuel into an internal combustion engine. It has become the primary fuel delivery system used in automotive petrol engines, having almost completely replaced carburetors in the late 1980s....

 to supplant carburetors in new-vehicle production.

Where multiple carburetors are used the mechanical linkage of their throttles must be synchronized for smooth engine running.

Catalytic carburetors

A catalytic carburetor mixes fuel vapor with water and air in the presence of heated catalysts such as nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...

 or platinum
Platinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...

. This breaks the fuel down into methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...

, alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

s, and other lighter-weight fuels. The U.S. Army used catalytic carburetors with great success in World War II, in the North African desert campaign.

While catalytic carburetors were made commercially available in the early 1930s, their widespread public use was limited. The addition of additives to commercial gasoline made it unsuitable for use in engines with catalytic carburetors. (Tetra-ethyl lead
Tetra-ethyl lead
Tetraethyllead , abbreviated TEL, is an organolead compound with the formula 4Pb. An inexpensive additive, its addition to gasoline from the 1920's allowed octane ratings and thus engine compression to be boosted significantly, increasing power and fuel economy...

, for example, was introduced in 1932 to raise gasoline's resistance to engine knock, thereby permitting the use of higher compression ratio
Compression ratio
The 'compression ratio' of an internal-combustion engine or external combustion engine is a value that represents the ratio of the volume of its combustion chamber from its largest capacity to its smallest capacity...

s.)

Vaporizers

Gasoline engines can be modified to run on tractor vaporizing oil (TVO) and such engines were once common in tractor
Tractor
A tractor is a vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction...

s. The modifications include a reduced compression ratio
Compression ratio
The 'compression ratio' of an internal-combustion engine or external combustion engine is a value that represents the ratio of the volume of its combustion chamber from its largest capacity to its smallest capacity...

 and a carburetor with a vaporizer. The vaporizer uses heat from the exhaust to vaporize the fuel. Widespread adoption of diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

s in tractors made the use of tractor vaporizing oil obsolete.

Manufacturers

  • Argelite, producer of Holley and Magneti Marelli carburetors for the Argentinian
    Argentina
    Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

     market
  • Autolite, a division of the Ford Motor Company
    Ford Motor Company
    Ford Motor Company is an American multinational automaker based in Dearborn, Michigan, a suburb of Detroit. The automaker was founded by Henry Ford and incorporated on June 16, 1903. In addition to the Ford and Lincoln brands, Ford also owns a small stake in Mazda in Japan and Aston Martin in the UK...

     from 1967-1973.
  • Ball & Ball, US manufacturer, eventually part of Carter
  • Bendix Stromberg and Bendix Technico
    Bendix Corporation
    The Bendix Corporation was an American manufacturing and engineering company which during various times in its 60 year existence made brake systems, aeronautical hydraulics, avionics, aircraft and automobile fuel control systems, radios, televisions and computers, and which licensed its name for...

     carburetors used on aircraft and vehicles made by Chrysler, IHC, Ford
    Ford Motor Company
    Ford Motor Company is an American multinational automaker based in Dearborn, Michigan, a suburb of Detroit. The automaker was founded by Henry Ford and incorporated on June 16, 1903. In addition to the Ford and Lincoln brands, Ford also owns a small stake in Mazda in Japan and Aston Martin in the UK...

    , GM
    General Motors
    General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...

    , AMC
    American Motors
    American Motors Corporation was an American automobile company formed by the 1954 merger of Nash-Kelvinator Corporation and Hudson Motor Car Company. At the time, it was the largest corporate merger in U.S. history.George W...

    , and Studebaker
    Studebaker
    Studebaker Corporation was a United States wagon and automobile manufacturer based in South Bend, Indiana. Founded in 1852 and incorporated in 1868 under the name of the Studebaker Brothers Manufacturing Company, the company was originally a producer of wagons for farmers, miners, and the...

  • Bing Carburetor, used on motorcycles, moped
    Moped
    Mopeds are a type of low-powered motorcycle designed to provide economical and relatively safe transport with minimal licensing requirements.Mopeds were once all equipped with bicycle-like pedals , but moped has been increasingly applied by governments to vehicles without pedals, based on their...

    s, aircraft, boats.
  • Carter carburetor, used on numerous makes of vehicles, including those made by Chrysler, IHC, Ford
    Ford Motor Company
    Ford Motor Company is an American multinational automaker based in Dearborn, Michigan, a suburb of Detroit. The automaker was founded by Henry Ford and incorporated on June 16, 1903. In addition to the Ford and Lincoln brands, Ford also owns a small stake in Mazda in Japan and Aston Martin in the UK...

    , GM
    General Motors
    General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...

    , AMC
    American Motors
    American Motors Corporation was an American automobile company formed by the 1954 merger of Nash-Kelvinator Corporation and Hudson Motor Car Company. At the time, it was the largest corporate merger in U.S. history.George W...

    , and Studebaker
    Studebaker
    Studebaker Corporation was a United States wagon and automobile manufacturer based in South Bend, Indiana. Founded in 1852 and incorporated in 1868 under the name of the Studebaker Brothers Manufacturing Company, the company was originally a producer of wagons for farmers, miners, and the...

    , as well as on industrial and agricultural equipment and small engines.
  • Claudel-Hobson
    Claudel-Hobson
    Claudel-Hobson was a series of British carburettors manufactured by the H. M. Hobson Components Ltd..First introduced in 1908, they were widely used in British car and aircraft engines in the early 20th Century...

    , UK
  • Dell'Orto
    Dell'Orto
    Dell'Orto is an Italian company, headquartered in Cabiate, specialized in the construction of carburetors and electronic injection systems. The company was founded in 1933 as "Società anonima Gaetano Dell'Orto e figli"...

     carburetors from Italy, used on cars and motorcycles
  • Demon Carburetors
  • Edelbrock
    Edelbrock
    Edelbrock, LLC is a specialty performance automotive and motorcycle aftermarket parts manufacturer based in Torrance, California. The company has five locations, including four in Torrance: its headquarters, a distribution center and museum, the Russell division , and the exhaust plant...

     performance carburetors
  • Hitachi carburetors, found on Japanese automobiles
  • Holley
    Holley Performance Products
    Holley Performance Products is an automotive performance company based in Bowling Green, Kentucky. Holley, when based in Michigan, was one of the major producers of carburetors, being supplied as standard equipment on many Detroit-built automobiles....

    , with usage as broad as Carter and Weber.
  • Keihin
    Keihin
    Keihin may refer to:* Keihin region in Japan* Keihin, a brand of motorcycle and powersports carburetor, common on Japanese and other motorcycles. The brand is manufactured by an epynominous keiretsu group company affiliated with Honda...

    , a keiretsu
    Keiretsu
    A is a set of companies with interlocking business relationships and shareholdings. It is a type of business group. The keiretsu has maintained dominance over the Japanese economy for the greater half of the twentieth century....

     group company affiliated with Honda
    Honda
    is a Japanese public multinational corporation primarily known as a manufacturer of automobiles and motorcycles.Honda has been the world's largest motorcycle manufacturer since 1959, as well as the world's largest manufacturer of internal combustion engines measured by volume, producing more than...

  • Lectron Fuel Sysytems carburetors
  • Marvel Schebler carburetor, used for aircraft, tractors, ...
  • Mikuni
    Mikuni
    is a leading Japanese carburettor manufacturing company that was founded in 1923 and incorporated in 1948. Their business activities are centred on carburettors, fuel injectors and other automobile related equipment...

    , common on Japanese motorcycles, especially in the 1980s. Mikuni also made Automotive Racing Carburetors for Japanese, British and European cars. Original equipment carburetors supplied on Mitsubishi engines.
  • Motec Engineering - high-performance updraft carburetors
  • Pierburg carburetor, in Saab
    Saab Automobile
    Saab Automobile AB, better known as Saab , is a Swedish car manufacturer owned by Dutch automobile manufacturer Swedish Automobile NV, formerly Spyker Cars NV. It is the exclusive automobile Royal Warrant holder as appointed by the King of Sweden...

    , Volvo
    Volvo
    AB Volvo is a Swedish builder of commercial vehicles, including trucks, buses and construction equipment. Volvo also supplies marine and industrial drive systems, aerospace components and financial services...

    , VW and Audi
    Audi
    Audi AG is a German automobile manufacturer, from supermini to crossover SUVs in various body styles and price ranges that are marketed under the Audi brand , positioned as the premium brand within the Volkswagen Group....

  • Rochester Products Division
    Rochester Products Division
    Rochester Products Division was a division of General Motors that manufactured carburetors, and related components including emissions control devices and cruise control systems in Rochester, New York...

    , USA (A General Motors subsidiary; also sold Weber/Magneti Marelli carburetors under license)
  • Solex
    Solex
    Solex was a French manufacturer of carburetors and the powered bicycle VéloSoleX.The Solex company was founded by Marcel Mennesson and Maurice Goudard to manufacture vehicle radiators...

     carburetor
  • SU carburetor widely used on British Commonwealth and European-designed vehicles
  • AMAL Carburetter Company
    Amal (motorcycle)
    AMAL is a British carburettor trademark. AMAL were the suppliers of carburettors to the British motorcycle industry and their products were present on the products of the largest British motorcycle manufacturers such as BSA and AMC...

    , supplier to the British motorcycle industry
  • UCAL FUEL SYSTEMS - Carburettors
  • Villiers UK Motorcycle and small engines
  • Walbro
    Walbro
    Walbro Corporation is a manufacturing company that specializes in small engine carburetion and supplier of auto parts. Otherwise, Walbro carburetors are commonly used on line-trimmers, leaf blowers, chain-saws, and edgers. Walbro was founded by Walter E. Walpole in November 1950...

     and Tillotson
    Tillotson
    Tillotson may refer to:* Giles Tillotson , British historian* John Tillotson , Archbishop of Canterbury* John Tillotson, , with wife Clara founded The Workbasket Magazine in 1935....

     carburetors for small engines
  • Weber carburetor
    Weber carburetor
    Weber is an Italian company producing carburetors, currently owned by Magneti Marelli Powertrain S.p.A., in turn part of the Fiat Group.The company was established as...

    , Italian, now made in Spain, owned by Magneti Marelli
  • Zenith
    Zenith Carburetters
    Zenith Carburetters was a British company making carburettors. In 1955 they joined with their major pre-war rival Solex Carburettors and over time the Zenith brand name fell into disuse...

     UK — Also produced the Zenith-Stromberg Carburetors


General information


American

CarburetorHenry Ford
Henry Ford
Henry Ford was an American industrialist, the founder of the Ford Motor Company, and sponsor of the development of the assembly line technique of mass production. His introduction of the Model T automobile revolutionized transportation and American industry...

 — Carburetor — Charles Nelson Pogue — Carburetor — Charles Nelson Pogue — Carburetor — Charles Nelson Pogue — Carburetor — Charles Nelson Pogue — Carburetor — J. R. Fish — Vapor fuel system — Robert S. Shelton — Fuel economy system for an internal combustion engine — Thomas H. W.

Other

  • G.B. Рatent 11119Mixing chamberDonát Bánki
    Donát Bánki
    Donát Bánki was a Hungarian mechanical engineer, inventor of the carburetor, togetherwith János Csonka, in 1893, as the Bánki-Csonka engine....


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK