Sleeve valve
Encyclopedia
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...
mechanism for piston engines, distinct from the usual poppet valve
Poppet valve
A poppet valve is a valve consisting of a hole, usually round or oval, and a tapered plug, usually a disk shape on the end of a shaft also called a valve stem. The shaft guides the plug portion by sliding through a valve guide...
. Sleeve-valve engines saw use in a number of pre-World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
luxury cars and in USA in the Willys-Knight
Willys-Knight
Willys-Knight is an automobile that was produced between 1914 and 1933 by the Willys-Overland Company of Toledo, Ohio.John North Willys purchased the Edwards Motor Car Company of Long Island, New York, in 1913, moving the operation to Elyria, Ohio, where Willys owned the plant that had previously...
car and light truck. They subsequently fell from use due to advances in poppet-valve technology, including sodium cooling, and to their tendency to burn a lot of lubricating oil or to seize due to lack of it. The Scottish Argyll
Argyll (automobile)
Argyll was a Scottish motor car marque manufactured from 1899 to 1932, and again from 1976 to around 1990.-The original Argyll marque:Alex Govan founded The Hozier Engineering Company in 1899, and it was at this factory that the first Argyll Voiturette was produced; copied from the contemporary...
company used its own, much simpler and efficient, single-sleeve system in its cars, a system which, after extensive development, saw substantial use in aircraft engine
Aircraft engine
An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...
s of the 1940s, such as the Napier Sabre
Napier Sabre
The Napier Sabre was a British H-24-cylinder, liquid cooled, sleeve valve, piston aero engine, designed by Major Frank Halford and built by Napier & Son during WWII...
and Bristol Hercules
Bristol Hercules
|-See also:-Bibliography:*Gunston, B. Classic World War II Aircraft Cutaways. Osprey. ISBN 1-85532-526-8*Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
and Centaurus
Bristol Centaurus
|-See also:-Bibliography:*Bridgman, L, Jane's Fighting Aircraft of World War II. Crescent. ISBN 0-517-67964-7*Gunston, Bill. Development of Piston Aero Engines. Cambridge, England. Patrick Stephens Limited, 2006. ISBN 0-7509-4478-1...
, only to be supplanted by the jet engine.
Description
A sleeve valve takes the form of one or more machined sleeves. It fits between the piston and the cylinder wall in the cylinder of an internal combustion engine where it rotates and/or slides, ports (holes) in the side of the sleeve(s) aligning with the cylinder's inlet and exhaust ports at the appropriate stages in the engine's cycle.Types of sleeve valve
The first successful sleeve valve was patented by Charles Yale Knight, and used twin alternating sliding sleeves. It was used in some luxury automobiles, notably Daimler, Mercedes-Benz, Minerva and Avions VoisinAvions Voisin
Avions Voisin was a French luxury automobile brand established by Gabriel Voisin.Gabriel B. Voisin was an aviation pioneer and manufacturer who in 1919 started producing cars using Knight-type sleeve valve engines at Issy-les-Moulineaux, an industrial suburb to the South West of Paris.Former...
. The higher oil consumption was heavily outweighed by the quietness of running and the very high mileages without servicing. Early poppet-valve systems required decarbonization at very low mileages.
The Burt-McCollum sleeve valve, as used by the Scottish company Argyll for its cars, and later adopted by Bristol for its radial aircraft engines, used a single sleeve which rotated around a timing axle set at 90 degrees to the cylinder axle. Mechanically simpler and more rugged, the Burt-McCollum valve had the additional advantage of reducing oil consumption (compared to other sleeve valve designs), while retaining the rational combustion chambers and big, uncluttered, porting area possible in the Knight
Knight Engine
The Knight Engine was an internal combustion engine, designed by American Charles Yale Knight , that used sleeve valves instead of the more common poppet valve construction.- History :...
system.
A small number of designs used a "cuff" sleeve in the cylinder head instead of the cylinder proper, providing a more "classic" layout compared to traditional poppet valve engines. This design also had the advantage of not having the piston within the sleeve, although in practice this appears to have had little practical value. On the downside, this arrangement limited the size of the ports to that of the cylinder head, whereas in-cylinder sleeves could have much larger ports.
Advantages
The main advantages of the sleeve-valve engine are:- Increased volumetric efficiencyVolumetric efficiencyVolumetric efficiency in internal combustion engine design refers to the efficiency with which the engine can move the charge into and out of the cylinders. More specifically, volumetric efficiency is a ratio of what quantity of fuel and air actually enters the cylinder during induction to the...
due to very large port openings. Sir Harry RicardoHarry RicardoSir Harry Ricardo was one of the foremost engine designers and researchers in the early years of the development of the internal combustion engine....
also demonstrated better mechanical efficiency. An additional advantage of the system is that the size of the ports can be readily controlled. This is important when an engine operates over a wide RPM range, since the speed at which air can enter and exit the cylinder is defined by the size of the duct leading to the cylinder, and varies according to the cube of the RPM. In other words, at higher RPM the engine typically requires larger ports that remain open for a greater proportion of the cycle, which is fairly easy to achieve with sleeve valves, but difficult in a poppet valve system.
- Good exhaust scavenging and controllable swirl of the inlet air/fuel mixture in single-sleeve designs. When the intake ports open, the fuel air mixture can be made to enter tangentially to the cylinder. This helps scavenging when exhaust/inlet timing overlap is used and a wide speed range required, whereas poor poppet valve exhaust scavenging can dilute the fresh air/fuel mixture intake to a greater degree, being more speed dependent (relying principally on exhaust/inlet system resonant tuning to separate the two streams). Greater freedom of combustion chamber design (few constraints other than the spark plug positioning) means that fuel/air mixture swirl at TDC can also be more controlled allowing improved ignition and flame travel which as demonstrated by Ricardo, at least one extra unit of compression ratio before detonation c.f. the poppet valve engine.
- The combustion chamberCombustion chamberA combustion chamber is the part of an engine in which fuel is burned.-Internal combustion engine:The hot gases produced by the combustion occupy a far greater volume than the original fuel, thus creating an increase in pressure within the limited volume of the chamber...
formed with the sleeve at the top of its stroke is ideal for complete, detonation-free combustion of the charge, as it does not have to contend with compromised chamber shape and hot exhaust (poppet) valve(s).
- No springs are involved in the sleeve valve system, therefore the power needed to operate the valve remains largely constant with the engine's RPMRevolutions per minuteRevolutions per minute is a measure of the frequency of a rotation. It annotates the number of full rotations completed in one minute around a fixed axis...
, meaning that the system can be used at very high speeds with no penalty for doing so. A problem with high-speed engines which use poppet valves is that as engine speed increases, the speed at which the valve moves also has to increase. This in turn increases the loads involved due to the inertia of the valve, which has to be opened quickly, brought to a stop, then reversed in direction and closed and brought to a stop again. Large valves that allow good air-flow have considerable mass and require a strong spring to overcome the opening inertia. At some point, the valve spring reaches its resonance frequencyResonanceIn physics, resonance is the tendency of a system to oscillate at a greater amplitude at some frequencies than at others. These are known as the system's resonant frequencies...
, causing a compression wave to oscillate within the spring, which in turn causes it to become effectively weaker and unable to properly close the valve. This valve floatValve floatValve float is an adverse condition which occurs when the poppet valves on an internal combustion engine valvetrain do not remain in contact with the camshaft lobe during the valve closure phase of the cam lobe profile...
can result in the valve not closing quickly, and it may strike the top of the rising piston. In addition, camshaft, pushrods, and valve rockers can be eliminated in a sleeve valve design, as the sleeve valves are generally driven by a single gear powered from the crankshaft. In an aircraft engine this provided reductions in weight and complexity.
- Longevity, as demonstrated in early automotive applications of the Knight engine. Prior to the advent of leaded gasolines, poppet-valve engines typically required grinding of the valves and valve seats after 20,000 to 30,000 miles (32,000 to 48,000 km) of service. Sleeve valves did not suffer from the wear and recession caused by the repetitive impact of the poppet valve against its seat. Sleeve valves were also subjected to less intense heat buildup than poppet valves, owing to their greater area of contact with other metal surfaces. In the Knight engine, carbon build-up actually helped to improve the sealing of the sleeves, the engines being said to "improve with use", in contrast to poppet valve engines, which lose compression and power as valves and valve stems/guides wear. Due to the continued motion of the sleeve (Burt-McCollum type), the high wear points linked to poor lubrication in the TDC/BDC of piston course are suppressed, therefore rings and cylinders lasted much longer.
- Cylinder head is not required to house valves, allowing the spark plug to be placed in the best possible location for efficient ignition of the combustion mixture. For very big engines, where flame propagation speed limits both size and speed, the swirl induced by ports as described by Ricardo can be an additional advantage.
Most of these advantages were evaluated and established during the 1920s by Sir Harry Ricardo, possibly the sleeve-valve engine's greatest advocate. He conceded that some of these advantages were significantly eroded as fuels improved up to and during World War II and as sodium-cooled exhaust valves were introduced in high output aircraft engines.
Disadvantages
The sleeve valve's one major disadvantage is that perfect sealing is difficult to achieve. In a poppet valve engine, the piston possesses piston ringPiston ring
A piston ring is a split ring that fits into a groove on the outer diameter of a piston in a reciprocating engine such as an internal combustion engine or steam engine.The three main functions of piston rings in reciprocating engines are:...
s (often at least three and sometimes as many as eight) which form a seal with the cylinder bore. During the "breaking in" period (known as "running-in" in the UK) any imperfections in one are scraped into the other, resulting in a good fit. This type of "breaking in" is not possible on a sleeve-valve engine, however, because the piston and sleeve move in different directions and in some systems even rotate in relation to one another. Unlike a traditional design, the imperfections in the piston do not always line up with the same point on the sleeve. In the 1940s this was not a major concern because the poppet valves of the time typically leaked appreciably more than they do today, so that oil consumption was significant in either case.
The high oil consumption problem associated with the Knight double sleeve valve was fixed with the Burt-McCollum single sleeve valve, as perfected by Bristol. At top dead center
Dead centre
In a reciprocating engine, the dead centre is the position of a piston in which it is farthest from, or nearest to, the crankshaft. The former is known as top dead centre while the latter is known as bottom dead centre ....
(TDC), the single sleeve valve rotates in relation to the piston. This prevents boundary lubrication problems, as piston ring ridge wear at TDC and bottom dead center (BDC) does not occur. The Hercules overhaul time was rated at 3,000 hr at wide open throttle. An inherent disadvantage may be that the piston in its course partially obscures the ports, thus making it difficult for gases to flow during the crucial overlap between the intake and exhaust valve timing usual in modern engines. The German engineer Max Bentele
Max Bentele
Max Bentele was a pioneer in the field of jet aircraft turbines and mechanical engineering...
, after studying a British sleeve valve aero engine (probably a Hercules
Bristol Hercules
|-See also:-Bibliography:*Gunston, B. Classic World War II Aircraft Cutaways. Osprey. ISBN 1-85532-526-8*Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
), complained that the arrangement required more than 100 gearwheels for the engine, too many for his taste.
Charles Yale Knight
In 1901 Knight bought an air-cooled, single-cylinder three-wheeler whose noisy valves annoyed him. He believed that he could design a better engine and did so, inventing his double sleeve principle in 1904. Backed by Chicago entrepreneur L.B. Kilbourne, a number of engines were constructed followed by the "Silent Knight" touring car which was shown at the 1906 Chicago Auto Show.Knight's design had two cast-iron sleeves per cylinder, one sliding inside the other with the piston inside the inner sleeve. The sleeves were operated by small connected rods actuated by an eccentric shaft. They had ports cut out at their upper ends. The design was remarkably quiet, and the sleeve valves needed little attention. It was, however, more expensive to manufacture due to the precision grinding required on the sleeves' surfaces. It also used more oil at high speeds and was harder to start in cold weather.
Although he was initially unable to sell his Knight Engine
Knight Engine
The Knight Engine was an internal combustion engine, designed by American Charles Yale Knight , that used sleeve valves instead of the more common poppet valve construction.- History :...
in the United States, a long sojourn in England, involving extensive further development and refinement by Daimler
Daimler Motor Company
The Daimler Motor Company Limited was an independent British motor vehicle manufacturer founded in London by H J Lawson in 1896, which set up its manufacturing base in Coventry. The right to the use of the name Daimler had been purchased simultaneously from Gottlieb Daimler and Daimler Motoren...
supervised by their consultant Dr Frederick Lanchester
Frederick Lanchester
Frederick William Lanchester, Hon FRAeS was an English polymath and engineer who made important contributions to automotive engineering, aerodynamics and co-invented the field of operations research....
eventually secured Daimler and several luxury car firms as customers willing to pay his expensive premiums. He first patented the design in England in 1908. As part of the licensing agreement, "Knight" was to be included in the car's name.
Among the companies using Knight's technology were Gabriel Voisin
Gabriel Voisin
Gabriel Voisin was an aviation pioneer and the creator of Europe's first manned, engine-powered, heavier-than-air aircraft capable of a sustained , circular, controlled flight, including take-off and landing. It was flown by Henry Farman on January 13, 1908 near Paris, France...
(in his Avions Voisin
Avions Voisin
Avions Voisin was a French luxury automobile brand established by Gabriel Voisin.Gabriel B. Voisin was an aviation pioneer and manufacturer who in 1919 started producing cars using Knight-type sleeve valve engines at Issy-les-Moulineaux, an industrial suburb to the South West of Paris.Former...
cars), Daimler (even in their V-12 "Double Six", from 1909–1930s), Panhard
Panhard
Panhard is currently a French manufacturer of light tactical and military vehicles. Its current incarnation was formed by the acquisition of Panhard by Auverland in 2005. Panhard had been under Citroën ownership, then PSA , for 40 years...
(1911–39), Mercedes
Mercedes (car)
Mercedes was a brand of the Daimler-Motoren-Gesellschaft . DMG which began to develop in 1900, after the death of its co-founder, Gottlieb Daimler...
(1909–24), Willys
Willys
Willys was the brand name used by Willys-Overland Motors, an American automobile company best known for its design and production of military Jeeps and civilian versions during the 20th century.-Early History:In 1908, John Willys bought the Overland Automotive Division of Standard Wheel Company...
(as the Willys-Knight
Willys-Knight
Willys-Knight is an automobile that was produced between 1914 and 1933 by the Willys-Overland Company of Toledo, Ohio.John North Willys purchased the Edwards Motor Car Company of Long Island, New York, in 1913, moving the operation to Elyria, Ohio, where Willys owned the plant that had previously...
, plus the associated Falcon-Knight), Stearns
Stearns (automobile)
F. B. Stearns and Company was a manufacturer of luxury cars in Cleveland, Ohio marketed under the brand names Stearns and Stearns-Knight.-History:...
, Mors
Mors (automobile)
The Mors automobile factory was an early French car manufacturer. It was one of the first to take part in automobile racing, beginning in 1897, due to the belief of the company founder, Émile Mors, in racing's technical and promotional benefits...
, Peugeot
Peugeot
Peugeot is a major French car brand, part of PSA Peugeot Citroën, the second largest carmaker based in Europe.The family business that precedes the current Peugeot company was founded in 1810, and manufactured coffee mills and bicycles. On 20 November 1858, Emile Peugeot applied for the lion...
, and Belgium's Minerva company, some thirty companies in all. Itala also experimented with sleeve valves.
Upon Knight's return to America he was able to get some firms to use his design; here his brand name was "Silent Knight
Silent Knight
The Silent Knight is a fictional medieval hero appearing in comic books published by DC Comics. The character first appeared in The Brave and the Bold #1 , and was created by Robert Kanigher and Irv Novick...
" (1905–1907) — the selling point was that his engines were quieter than those with standard poppet valves. The best known of these were the F.B. Stearns
Stearns (automobile)
F. B. Stearns and Company was a manufacturer of luxury cars in Cleveland, Ohio marketed under the brand names Stearns and Stearns-Knight.-History:...
Company of Cleveland, which sold a car named the Stearns-Knight
Stearns-Knight
Stearns-Knight was a luxury automobile produced in Cleveland, Ohio first by the F.B. Stearns Company from 1900 to 1925, and then under ownership by WillysOverland Company of Toledo, Ohio until 1929....
, and the Willys
Willys
Willys was the brand name used by Willys-Overland Motors, an American automobile company best known for its design and production of military Jeeps and civilian versions during the 20th century.-Early History:In 1908, John Willys bought the Overland Automotive Division of Standard Wheel Company...
firm which offered a car called the Willys-Knight
Willys-Knight
Willys-Knight is an automobile that was produced between 1914 and 1933 by the Willys-Overland Company of Toledo, Ohio.John North Willys purchased the Edwards Motor Car Company of Long Island, New York, in 1913, moving the operation to Elyria, Ohio, where Willys owned the plant that had previously...
, which was produced in far greater numbers than any other sleeve-valve car.
Burt-McCollum
The Burt-McCollum sleeve valve consisted of a single sleeve, which was given a combination of up-and-down and partial rotary motion. It was developed in about 1909 and was first used in the 1911 ArgyllArgyll (automobile)
Argyll was a Scottish motor car marque manufactured from 1899 to 1932, and again from 1976 to around 1990.-The original Argyll marque:Alex Govan founded The Hozier Engineering Company in 1899, and it was at this factory that the first Argyll Voiturette was produced; copied from the contemporary...
car. Argyll went out of business after high expenses of a litigation with the Knight patent holders. Its greatest success was in Bristol's large aircraft engines, and was also used in the Napier Sabre
Napier Sabre
The Napier Sabre was a British H-24-cylinder, liquid cooled, sleeve valve, piston aero engine, designed by Major Frank Halford and built by Napier & Son during WWII...
and Rolls-Royce Eagle aircraft engines. The single sleeve system also cured the high oil consumption associated with the Knight double sleeve valve.
A number of sleeve valve aircraft engines were developed following a seminal 1927 research paper from the RAE
Royal Aircraft Establishment
The Royal Aircraft Establishment , was a British research establishment, known by several different names during its history, that eventually came under the aegis of the UK Ministry of Defence , before finally losing its identity in mergers with other institutions.The first site was at Farnborough...
by Harry Ricardo
Harry Ricardo
Sir Harry Ricardo was one of the foremost engine designers and researchers in the early years of the development of the internal combustion engine....
. This paper outlined the advantages of the sleeve valve, and suggested that poppet valve engines would not be able to offer power outputs much beyond 1500 hp (1,100 kW). Napier
Napier Lion
The Napier Lion was a 12-cylinder broad arrow configuration aircraft engine built by Napier & Son starting in 1917, and ending in the 1930s. A number of advanced features made it the most powerful engine of its day, and kept it in production long after contemporary designs had stopped production...
and Bristol
Bristol Aeroplane Company
The Bristol Aeroplane Company, originally the British and Colonial Aeroplane Company, was both one of the first and one of the most important British aviation companies, designing and manufacturing both airframes and aero engines...
began the development of sleeve-valve engines that would eventually result in two of the most powerful piston engines in the world: the Napier Sabre
Napier Sabre
The Napier Sabre was a British H-24-cylinder, liquid cooled, sleeve valve, piston aero engine, designed by Major Frank Halford and built by Napier & Son during WWII...
and Bristol Centaurus
Bristol Centaurus
|-See also:-Bibliography:*Bridgman, L, Jane's Fighting Aircraft of World War II. Crescent. ISBN 0-517-67964-7*Gunston, Bill. Development of Piston Aero Engines. Cambridge, England. Patrick Stephens Limited, 2006. ISBN 0-7509-4478-1...
.
Potentially the most powerful of all sleeve-valve engines (though it never reached production) was the Rolls-Royce Crecy
Rolls-Royce Crecy
The Rolls-Royce Crecy was an unusual British experimental two-stroke, 90-degree, V12, liquid-cooled aero-engine of 1,536 cu.in capacity, featuring sleeve valves and direct petrol injection...
V-12 (oddly, using a 90 degree V-angle), two-stroke, direct-injected, force-scavenged (turbocharged) aero-engine of 26.1 litres capacity. It achieved a very high specific output, and surprisingly good specific fuel consumption (SFC). In 1945 the single-cylinder test-engine (E65) produced the equivalent of 5,000 HP (192 BHP/Litre) when water injected, although the full V12 would probably have been initially type rated at circa 2500 HP. Sir Harry Ricardo, who specified the layout and design goals, felt that a reliable 4,000 HP military rating would be possible. Ricardo was constantly frustrated during the war with Rolls-Royce
Rolls-Royce Limited
Rolls-Royce Limited was a renowned British car and, from 1914 on, aero-engine manufacturing company founded by Charles Stewart Rolls and Henry Royce on 15 March 1906 as the result of a partnership formed in 1904....
's (RR) efforts. Hives & RR were very much focused on their Merlin
Rolls-Royce Merlin
The Rolls-Royce Merlin is a British liquid-cooled, V-12, piston aero engine, of 27-litre capacity. Rolls-Royce Limited designed and built the engine which was initially known as the PV-12: the PV-12 became known as the Merlin following the company convention of naming its piston aero engines after...
, Griffon
Rolls-Royce Griffon
The Rolls-Royce Griffon is a British 37-litre capacity, 60-degree V-12, liquid-cooled aero engine designed and built by Rolls-Royce Limited...
, then Eagle and finally Whittle
Frank Whittle
Air Commodore Sir Frank Whittle, OM, KBE, CB, FRS, Hon FRAeS was a British Royal Air Force engineer officer. He is credited with independently inventing the turbojet engine Air Commodore Sir Frank Whittle, OM, KBE, CB, FRS, Hon FRAeS (1 June 1907 – 9 August 1996) was a British Royal Air...
's jets, which had a clearly defined production purpose. Ricardo and Tizard
Henry Tizard
Sir Henry Thomas Tizard FRS was an English chemist and inventor and past Rector of Imperial College....
eventually realized that the Crecy would never get the development attention it deserved unless it was specified for installation in a particular aircraft, but by 1945, their "Spitfire
Supermarine Spitfire
The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and many other Allied countries throughout the Second World War. The Spitfire continued to be used as a front line fighter and in secondary roles into the 1950s...
on steroids" concept of a rapidly climbing interceptor powered by the lightweight Crecy engine had become an aircraft without a purpose.
Following World War II the sleeve valve disappeared from use, as the previous problems with sealing and wear on poppet valves had been remedied by the use of better materials, and the inertia
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...
problems with the use of large valves were reduced by using several smaller valves instead, giving increased flow area and reduced mass. Up to that point, the single sleeve valve had won every contest against the poppet valve hands down in comparison of power to displacement. The difficulty of nitride hardening, then finish-grinding the sleeve valve for truing the circularity, may have been a factor in its lack of commercial application.
Modern usage
The sleeve valve has begun to make something of a comeback, due to modern materials, dramatically better engineering tolerancesMachining
Conventional machining is a form of subtractive manufacturing, in which a collection of material-working processes utilizing power-driven machine tools, such as saws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to physical remove material to achieve a desired...
and modern construction techniques, which produce a sleeve valve that leaks very little oil. However, most advanced engine research is concentrated on improving other internal combustion engine designs, such as the Wankel
Wankel engine
The Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into a rotating motion instead of using reciprocating pistons. Its four-stroke cycle takes place in a space between the inside of an oval-like epitrochoid-shaped housing and a rotor that...
.
Mike Hewland and Keith Duckworth
Keith Duckworth
David Keith Duckworth, , was an English mechanical engineer. He is most famous for designing the Cosworth DFV engine, an engine that revolutionised the sport of Formula One....
experimented with a single-cylinder sleeve-valve test engine when looking at Cosworth DFV
Cosworth DFV
The DFV is an internal combustion engine that was originally produced by Cosworth for Formula One motor racing. Named Four Valve because of the four valves per cylinder, and Double as it was a V8 development of the earlier, four-cylinder FVA , making it a Double Four Valve engine...
replacements. Hewland claimed to have obtained 72 hp from a 500 cc single-cylinder engine, with a specific fuel consumption
Brake specific fuel consumption
Brake Specific Fuel Consumption is a measure of fuel efficiency within a shaft reciprocating engine.It is the rate of fuel consumption divided by the power produced. It may also be thought of as power-specific fuel consumption, for this reason...
of 170 gr/HP/hr -.45 to .39 lb/hp/hr-, the engine being able to work on creosote
Creosote
Creosote is the portion of chemical products obtained by the distillation of a tar that remains heavier than water, notably useful for its anti-septic and preservative properties...
, with no specific lubrication supply for the sleeve. Hewland reported also that the highest temperature measured in the cylinder head didn't exceed 150 °C, sleeve temperatures were around 140 °C, T was 270 °C in the center of cylinder and 240 °C in the edge.
A recent SAE paper deals with a high-speed, small-displacement sleeve-valve engine, calculated, but not experimentally shown, to have a higher SFC than the poppet-valve alternative, a non-surprising result, considering the difficulty in obtaining the high intake and exhaust overlap that very fast-running engines require, additional work compares two different side-opening intake strategies for sleeve-valve engines.
An unusual form of four-stroke model engine
Model engine
In radio-controlled modeling, a model engine is an internal combustion engine used to power a radio-controlled aircraft, radio-controlled car, radio-controlled boat, free flight and control line aircraft, and tether car models also use these engines....
that uses what is essentially a sleeve-valve format, is the British RCV series of "SP" model engines, which use a rotating cylinder liner driven through a bevel gear at the cylinder liner's "bottom", and even more unusually have the propeller shaft emerging from what would normally be the cylinder's "top", at the extreme front of the engine, achieving a 2:1 gear reduction ratio compared to the vertically oriented crankshaft's rotational speed. The same firm's "CD" series of model engines use a conventional upright single cylinder instead, with the crankshaft used to directly spin the propeller, and also use the rotating cylinder valve. As a parallel with the earlier Charles Knight-designed sleeve-valved automotive powerplants, any RCV sleeve-valved model engine that is run on model glow engine fuel using castor oil
Castor oil
Castor oil is a vegetable oil obtained from the castor bean . Castor oil is a colorless to very pale yellow liquid with mild or no odor or taste. Its boiling point is and its density is 961 kg/m3...
as a small percentage (about 2% to 4% content) of the lubricant in the fuel allows the "varnish" created through engine operation to provide a better pneumatic seal between the rotating cylinder valve and the unitized engine cylinder/head castings, initially formed while the engine is being broken in.
Steam engine
Sleeve valves have occasionally been used on steam engines, for example the SR Leader classSR Leader Class
The Leader was a class of experimental 0-6-6-0T articulated steam locomotive, produced in the United Kingdom to the design of the innovative engineer Oliver Bulleid. The Leader was an attempt to extend the life of steam traction by eliminating many of the operational drawbacks associated with...
.
See also
Sleeve valve engines- D slide valveD slide valveThe slide valve is a rectilinear valve used to control the admission of steam into, and emission of exhaust from, the cylinder of a steam engine.-Use:...
- Piston valvePiston valveA piston valve is a device used to control the motion of a fluid along a tube or pipe by means of the linear motion of a piston within a chamber or cylinder.Examples of piston valves are:...
- Corliss valve