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carburretor [2007/02/27 00:29]
Looney
carburretor [2016/08/18 20:27] (current)
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 ===== Carburretor ===== ===== Carburretor =====
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-STILL BEING EDITED!!! 
  
  
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 ==== Operation ==== ==== Operation ====
 {{800px-highperformancecarburetor.jpg?​500}} {{800px-highperformancecarburetor.jpg?​500}}
 +
 Carburetors are either: Carburetors are either:
-*'''​Fixed Venturi'''​, in which the varying air velocity in the venturi alters the fuel flow; this architecture is employed in most downdraft carburetors found on American and some Japanese cars +  ​*Fixed Venturi, in which the varying air velocity in the venturi alters the fuel flow; this architecture is employed in most downdraft carburetors found on American and some Japanese 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. These types of carburetors are commonly equipped with accelerator pumps to make up for a particular shortcoming of this design. 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 carburettors rise to a position of domination in the UK car market, though such carburetors were also very widely used on Volvos and other non-UK makes. Other similar designs are used on some European and a few Japanese automobiles. These carburetors are also referred to as "​constant velocity"​ or "​constant vacuum"​ carburetors.+  * 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. These types of carburetors are commonly equipped with accelerator pumps to make up for a particular shortcoming of this design. 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 carburettors rise to a position of domination in the UK car market, though such carburetors were also very widely used on Volvos and other non-UK makes. Other similar designs are 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 (no needle valve) but 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 ensured good mixing and airflow over a range of engine speeds. ​ Some models of Ford Capri were equipped with VV carburetors. An interesting variation was Ford's VV (Variable Venturi) carburetor, which was essentially a fixed venturi carburetor (no needle valve) but 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 ensured good mixing and airflow over a range of engine speeds. ​ Some models of Ford Capri were equipped with VV carburetors.
  
 The carburetor must under all engine operating conditions: The carburetor must under all engine operating conditions:
-*Measure the airflow of the engine  +  ​*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) +  *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+  *Mix the two finely and evenly
  
-This job would be simple if air and petrol (gasoline) 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 at 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]]s:+This job would be simple if air and petrol (gasoline) 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 at 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 ​forces:
  
-*Cold start +  ​*Cold start 
-*Hot start +  *Hot start 
-*Idling or slow-running +  *Idling or slow-running 
-*Acceleration +  *Acceleration 
-*High speed / high power at full throttle +  *High speed / high power at full throttle 
-*Cruising at part throttle (light load)+  *Cruising at part throttle (light load)
  
-In addition, modern carburetors are required to do this while maintaining low rates of [[Automobile emissions control|exhaust emissions]]. ​+In addition, modern carburetors are required to do this while maintaining low rates of [[exhaust emissions]]. ​
  
 To function correctly under all these conditions, most carburetors contain a complex set of mechanisms to support several different operating modes, called ''​circuits''​. To function correctly under all these conditions, most carburetors contain a complex set of mechanisms to support several different operating modes, called ''​circuits''​.
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 ===Basics==== ===Basics====
 {{carburetor2.png?​500}} {{carburetor2.png?​500}}
-A carburetor basically consists of an open pipe, a "​throat"​ or "​barrel"​ through which the air passes into the inlet manifold 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 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 [[bowden ​cable|cable]] ​or a mechanical linkage of rods and joints or rarely by [[Hillman Imp|pneumatic link]], to the accelerator ​[[pedal]] on a car or the equivalent control on other vehicles or equipment.+ 
 +A carburetor basically consists of an open pipe, a "​throat"​ or "​barrel"​ through which the air passes into the inlet manifold 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 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 or a mechanical linkage of rods and joints or rarely by pneumatic link, to the accelerator pedal 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. Fuel flow in response to a particular pressure drop in the venturi is adjusted by means of precisely-calibrated orifices, referred to as ''​jets'',​ in the fuel path. Fuel is introduced into the air stream through small holes at the narrowest part of the venturi. Fuel flow in response to a particular pressure drop in the venturi is adjusted by means of precisely-calibrated orifices, referred to as ''​jets'',​ in the fuel path.
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 === Main open-throttle circuit === === Main open-throttle circuit ===
-As the [[throttle]] is progressively opened, the manifold vacuum reduces, since there is less restriction on the airflow, reducing the flow through the idle and off-idle circuits. This is where the venturi shape of the carburetor throat comes into play, due to [[Bernoulli'​s principle]] (''​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 progressively opened, the manifold vacuum reduces, since there is less restriction on the airflow, reducing the flow through the idle and off-idle circuits. This is where the venturi shape of the carburetor throat comes into play, due to Bernoulli'​s principle (''​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. 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.
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 In addition, the choke is connected to a "fast idle cam" or other such device which prevents the throttle from closing fully, which could starve the venturis of vacuum and cause the engine to stall. This also serves as a way to help the engine warm up quickly by idling it at a higher than normal speed. In addition, it increases airflow throughout the intake system which helps to better atomize the cold fuel and smooth out the idle. In addition, the choke is connected to a "fast idle cam" or other such device which prevents the throttle from closing fully, which could starve the venturis of vacuum and cause the engine to stall. This also serves as a way to help the engine warm up quickly by idling it at a higher than normal speed. In addition, it increases airflow throughout the intake system which helps to better atomize the cold fuel and smooth out the idle.
  
-In older carbureted cars, the choke was controlled by a cable connected to a pull-knob on the dashboard operated by the driver. In most carbureted cars produced from the mid 1960s onward (mid 1950s in the United States) it is usually automatically controlled by a [[thermostat]] employing a [[Bi-metal|bimetallic spring]], which is exposed to engine heat. 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 ​[[electricity|electrical]] 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.+In older carbureted cars, the choke was controlled by a cable connected to a pull-knob on the dashboard operated by the driver. In most carbureted cars produced from the mid 1960s onward (mid 1950s in the United States) it is usually automatically controlled by a [[thermostat]] employing a bimetallic spring, which is exposed to engine heat. 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 ​an electrical 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. 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.
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 === Other elements === === 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]] or [[automobile emissions control]]. 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. +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 or automobile emissions control. 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. 
-.+
  
 ==Fuel supply== ==Fuel supply==
 === Float chamber === === Float chamber ===
-To ensure a ready supply of fuel, 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]]. The correct fuel level in the bowl is maintained by means of a [[float]] controlling an inlet [[valve]], in a manner very similar to that employed in [[toilet]] tanks. 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 scribed 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]] 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 well 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.+To ensure a ready supply of fuel, 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]]. The correct fuel level in the bowl is maintained by means of a [[float]] controlling an inlet [[valve]], in a manner very similar to that employed in toilet tanks. 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 scribed 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 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 well 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]] 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 race]]s, 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. 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]] 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 race]]s, 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.
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 == Multiple carburetor barrels == == Multiple carburetor barrels ==
 {{800px-1961_ferrari_250_tr_61_spyder_fantuzzi_engine.jpg?​500}} {{800px-1961_ferrari_250_tr_61_spyder_fantuzzi_engine.jpg?​500}}
-Type 125 "Testa Rossa" engine in a 1961 [[Ferrari TR|Ferrari 250TR Spyder]] with 6 Weber 2-barrel carburetors intaking air through 12 "​trumpets"​ visible on top of the engine, one individually adjustable barrel for each cylinder; the ultimate in tunability.]]+Type 125 "Testa Rossa" engine in a 1961 Ferrari 250TR Spyder with 6 Weber 2-barrel carburetors intaking air through 12 "​trumpets"​ visible on top of the engine, one individually adjustable barrel for each cylinder; the ultimate in tunability.]]
  
-While low performance carburetors may have only one barrel, most carburetors have more than one venturi, or "​barrel",​ most commonly a two barrel, with 4 barrels being common in higher performance larger displacement engines, to accommodate the higher air flow rate with larger ​[[engine displacement]]. 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. ​+While low performance carburetors may have only one barrel, most carburetors have more than one venturi, or "​barrel",​ most commonly a two barrel, with 4 barrels being common in higher performance larger displacement engines, to accommodate the higher air flow rate with larger engine displacement. 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. ​
  
 Multiple carburetors can be mounted on a single engine, often with progressive linkages; three two barrel carburetors were frequently seen on high performance American V8s, and multiple four barrel carburetors are often now seen on very high performance engines. Multiple carburetors can be mounted on a single engine, often with progressive linkages; three two barrel carburetors were frequently seen on high performance American V8s, and multiple four barrel carburetors are often now seen on very high performance engines.
  
 == Carburetor adjustment == == 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]]s on an automotive carburetor, or a pilot-operated lever on piston-engined aircraft (since mixture is air [[density]] (altitude) dependent). The ([[stoichiometry|stoichiometric]]) air to [[gasoline]] [[ratio]] 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.+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]]s on an automotive carburetor, or a pilot-operated lever on piston-engined aircraft (since mixture is air density (altitude) dependent). The (stoichiometric) air to fuel ratio is 14.7:1, meaning that for each weight unit of fuel, 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]], hydrocarbon,​ and [[oxygen]] 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 for this purpose. The flame colour of stoichiometric burning is described as a "​bunsen blue", turning to yellow if the mixture is rich and white if too lean.+Ways to check carburetor mixture adjustment include: measuring the carbon monoxide, hydrocarbon,​ and oxygen 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 for this purpose. The flame colour of stoichiometric burning is described as a "​bunsen blue", turning to yellow if the mixture is rich and white if too lean.
  
-The mixture can also be judged after engine running by the state and [[color]] of the [[spark plug]]s: ​[[black]], dry [[soot]]y ​plugs indicate a too rich mixture, ​[[white]] to light [[gray (color)|gray]] ​deposits on the plugs indicate a lean mixture. The correct color should be a [[brown]]ish ​gray. +The mixture can also be judged after engine running by the state and color of the [[spark plug]]s: black, dry sooty plugs indicate a too rich mixture, white to light gray deposits on the plugs indicate a lean mixture. The correct color should be a brownish ​gray. 
-See also [[Spark plug#Reading spark plugs|reading spark plugs]].+See also [[Reading spark plugs|reading spark plugs]].
  
 In the early 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]]. These were mainly used to save costs (since they worked well enough to meet 1980s emissions requirements and were based on existing carburetor designs), but eventually disappeared as falling hardware prices and tighter emissions standards made [[fuel injection]] a standard item. In the early 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]]. These were mainly used to save costs (since they worked well enough to meet 1980s emissions requirements and were based on existing carburetor designs), but eventually disappeared as falling hardware prices and tighter emissions standards made [[fuel injection]] a standard item.
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 == History and development ==  == History and development == 
-The carburetor was invented by the [[Hungary|Hungarian]] [[engineer]] [[Donát Bánki]] in 1893. [[Frederick William Lanchester]] of [[Birmingham]], England experimented early on with the wick carburetor in cars. In 1896 Frederick and his brother built the first petrol driven car in England, a single cylinder 5&​nbsp;​hp (4&​nbsp;​kW) 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. This version completed a 1,000 mile (1600 km) tour in 1900 successfully incorporating the carburetor as an important step forward in automotive engineering.+The carburetor was invented by the Hungarian engineer Donát Bánki in 1893. Frederick William Lanchester of Birmingham, England experimented early on with the wick carburetor in cars. In 1896 Frederick and his brother built the first petrol driven car in England, a single cylinder 5&​nbsp;​hp (4&​nbsp;​kW) 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. This version completed a 1,000 mile (1600 km) tour in 1900 successfully incorporating the carburetor as an important step forward in automotive engineering.
  
-The word ''​carburetor''​ comes from the French ''​carbure'',​ meaning '[[carbide]]' ​[http://​www.answers.com/​carburet&​r=67]. To ''​carburete''​ means to combine with [[carbon]]. In fuel chemistry, the term has the more specific meaning of increasing the [[carbon]] (and therefore energy) content of a fuel by mixing it with a volatile ​[[hydrocarbon]].+The word ''​carburetor''​ comes from the French ''​carbure'',​ meaning '​carbide'​. To ''​carburete''​ means to combine with carbon. In fuel chemistry, the term has the more specific meaning of increasing the carbon (and therefore energy) content of a fuel by mixing it with a volatile hydrocarbon.
  
 == Catalytic carburetors == == Catalytic carburetors ==
-A catalytic carburetor mixes fuel fumes with water and air in the presence of heated catalysts such as nickel or platinum. This breaks the fuel down into methane, alcohols, and other lighter-weight fuels. The original catalytic carburetor was introduced to permit farmers to run tractors from modified and enriched ​[[Tractor vaporising oil|kerosene]].  The U.S. Army also used catalytic carburetors with great success in World War II, in the North African desert campaign.+A catalytic carburetor mixes fuel fumes with water and air in the presence of heated catalysts such as nickel or platinum. This breaks the fuel down into methane, alcohols, and other lighter-weight fuels. The original catalytic carburetor was introduced to permit farmers to run tractors from modified and enriched kerosene. ​ The U.S. Army also 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, two major factors limited their widespread public use.  First, the addition of additives to commercial gasoline made it unsuitable for use in engines with catalytic carburetors (tetraethyl lead was introduced in 1932 to raise gasoline'​s resistance to [[Engine knock|spontaneous combustion]], thereby permitting the use of higher compression ratios). ​  ​Second,​ the economic advantage of using [[Tractor vaporising oil|kerosene]] over gasoline faded in the 1930s, eliminating the catalytic carburetor'​s primary advantage.+While catalytic carburetors were made commercially available in the early 1930s, two major factors limited their widespread public use.  First, the addition of additives to commercial gasoline made it unsuitable for use in engines with catalytic carburetors (tetraethyl lead was introduced in 1932 to raise gasoline'​s resistance to spontaneous combustion, thereby permitting the use of higher compression ratios). ​  ​Second,​ the economic advantage of using kerosene over gasoline faded in the 1930s, eliminating the catalytic carburetor'​s primary advantage.
carburretor.txt · Last modified: 2016/08/18 20:27 (external edit)