Carburetors
Carburetors are provided with a float chamber to provide a constant hydrostatic head of fuel above the carburettor's metering jets, thus a constant pressure. The float chamber itself does not vary the pressure according to demand, but it does vary the supply flowrate with demand, to keep this pressure constant.
The valve is often described as a needle valve, although this is a misnomer. A true needle valve uses a tapered needle in a tapered seat, so as to provide fine control over flow rate. The float valve uses a pointed needle against a square-edged seat, to give a positive shut-off.
As the float relies on gravity, the chamber must be mounted vertically. Some designs, such as the SU, may allow a separate float chamber body to be adjusted relative to the carburettor to compensate for this. Acceleration effects may also apply a forwards force on the float and so the float hinges often have to be mounted across the car to avoid surging. Some designs, such as the Stromberg use wide, shallow floats to reduce surging.
One drawback of the basic type of float chamber described is that it only operates correctly when it is the right way up, so more sophisticated solutions are needed in aircraft.
A valve is a device or natural object that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically fittings, but are usually discussed as a separate category. In an open valve, fluid flows in a direction from higher pressure to lower pressure. The word is derived from the Latin valva, the moving part of a door, in turn from volvere, to turn, roll.
A carburetor is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the Venturi tube in the main metering circuit, though various other components are also used to provide extra fuel or air in specific circumstances.
A diving regulator is a pressure regulator that controls the pressure of breathing gas for diving. The most commonly recognised application is to reduce pressurized breathing gas to ambient pressure and deliver it to the diver, but there are also other types of gas pressure regulator used for diving applications. The gas may be air or one of a variety of specially blended breathing gases. The gas may be supplied from a scuba cylinder carried by the diver or via a hose from a compressor or high-pressure storage cylinders at the surface in surface-supplied diving. A gas pressure regulator has one or more valves in series which reduce pressure from the source, and use the downstream pressure as feedback to control the delivered pressure, or the upstream pressure as feedback to prevent excessive flow rates, lowering the pressure at each stage.
The Zenith Carburetter Company Limited was a British company making carburettors in Stanmore Middlesex, founded in 1912 as a subsidiary of the French Société du carburateur Zénith. In 1965, the company joined with its major pre-war rival Solex Carburettors, and over time, the Zenith brand name fell into disuse. The rights to the Zenith designs were owned by Solex UK.
Autogas or LPG is liquefied petroleum gas (LPG) used as a fuel in internal combustion engines in vehicles as well as in stationary applications such as generators. It is a mixture of propane and butane.
A needle valve is a type of valve with 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.
George Bailey Brayton was an American mechanical engineer and inventor. He was noted for introducing the constant pressure engine that is the basis for the gas turbine, and which is now referred to as the Brayton cycle.
In internal combustion engines with carburetors, a choke valve or choke modifies the air pressure in the intake manifold, thereby altering the air–fuel ratio entering the engine. Choke valves are generally used in naturally aspirated engines to supply a richer fuel mixture when starting the engine. Most choke valves in engines are butterfly valves mounted upstream of the carburetor jet to produce a higher partial vacuum, which increases the fuel draw.
A throttle is the mechanism by which fluid flow is managed by constriction or obstruction.
The Quadrajet is a four barrel carburetor, made by the Rochester Products Division of General Motors. Its first application was the new-for-1965 Chevy 396ci engine. Its last application was on the 1990 Oldsmobile 307 V8 engine, which was last used in the Cadillac Brougham and full size station wagons made by Chevrolet, Pontiac, Oldsmobile, and Buick.
Miss Shilling's orifice was a very simple technical device created to counter engine cut-outs experienced during negative G manoeuvres in early Spitfire and Hurricane fighter aeroplanes during the Battle of Britain. Officially called the R.A.E. restrictor, it was referred to under various names, such as Miss Tilly's diaphragm or the Tilly orifice in reference to its inventor, Beatrice "Tilly" Shilling.
AMAL was a British engineering company servicing the motorcycle and other light-engineering motor industries between 1927 and 1993 based in Birmingham, England.
A thermal expansion valve or thermostatic expansion valve is a component in vapor-compression refrigeration and air conditioning systems that controls the amount of refrigerant released into the evaporator and is intended to regulate the superheat of the refrigerant that flows out of the evaporator to a steady value. Although often described as a "thermostatic" valve, an expansion valve is not able to regulate the evaporator's temperature to a precise value. The evaporator's temperature will vary only with the evaporating pressure, which will have to be regulated through other means.
The wax thermostatic element was invented in 1934 by Sergius Vernet (1899–1968). Its principal application is in automotive thermostats used in the engine cooling system. The first applications in the plumbing and heating industries were in Sweden (1970) and in Switzerland (1971).
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.
A plenum chamber is a pressurised housing containing a fluid at positive pressure. One of its functions is to equalise pressure for more even distribution, compensating for irregular supply or demand. It is typically relatively large in volume and thus has relatively low velocity compared to the system's other components. In wind tunnels, rockets, and many flow applications, it is a chamber upstream on the fluid flow where the fluid initially resides. It can also work as an acoustic silencer.
The Reece-Fish carburettor was a carburettor used by Mini Se7en racers in the 60s and 70s.
SU carburettors were made by a British manufacturer of constant-depression carburettors. Their designs were in mass production during most of the twentieth century.
Of the three types of carburetors used on large, high-performance aircraft engines manufactured in the United States during World War II, the Bendix-Stromberg pressure carburetor was the one most commonly found. The other two carburetor types were manufactured by Chandler Groves and Chandler Evans Control Systems (CECO). Both of these types of carburetors had a relatively large number of internal parts, and in the case of the Holley Carburetor, there were complications in its "variable venturi" design.
