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40-463: The Cessna 340 is a twin piston engine pressurized business aircraft that was manufactured by Cessna . The Cessna 335 is an unpressurized version, which appears the same externally as the 340. It sold in smaller numbers than the 340. The 340 was conceived as a cabin-class development of the successful Cessna 310 . The 340 is a six-seat aircraft, with four passenger seats, an aisle and an airstair door. The tail and landing gear were based on

80-597: A capacity of 1,820 L (64 cu ft), making a total capacity of 25,480 L (900 cu ft) for the largest versions. For piston engines, an engine's capacity is the engine displacement , in other words the volume swept by all the pistons of an engine in a single movement. It is generally measured in litres (l) or cubic inches (c.i.d., cu in, or in ) for larger engines, and cubic centimetres (abbreviated cc) for smaller engines. All else being equal, engines with greater capacities are more powerful and consumption of fuel increases accordingly (although this

120-698: A circular groove in the piston head. The rings fit closely in the groove and press lightly against the cylinder wall to form a seal, and more heavily when higher combustion pressure moves around to their inner surfaces. It is common to classify such engines by the number and alignment of cylinders and total volume of displacement of gas by the pistons moving in the cylinders usually measured in cubic centimetres (cm or cc) or litres (l) or (L) (US: liter). For example, for internal combustion engines, single and two-cylinder designs are common in smaller vehicles such as motorcycles , while automobiles typically have between four and eight, and locomotives and ships may have

160-469: A cylinder to drive a reciprocating engine in a local-pollution-free urban vehicle. Torpedoes may use a working gas produced by high test peroxide or Otto fuel II , which pressurize without combustion. The 230 kg (510 lb) Mark 46 torpedo , for example, can travel 11 km (6.8 mi) underwater at 74 km/h (46 mph) fuelled by Otto fuel without oxidant . Quantum heat engines are devices that generate power from heat that flows from

200-418: A dozen cylinders or more. Cylinder capacities may range from 10 cm or less in model engines up to thousands of liters in ships' engines. The compression ratio affects the performance in most types of reciprocating engine. It is the ratio between the volume of the cylinder, when the piston is at the bottom of its stroke, and the volume when the piston is at the top of its stroke. The bore/stroke ratio

240-512: A helical spring backing have two scraping lands of various detailed form. On the other hand, multi-piece steel oil control rings usually consist of two thin steel rings (called rails ) with a spacer-expander spring between them to keep the two rails apart and provide radial pressure. The gap in the piston ring compresses to a few thousandths of an inch when inside the cylinder bore. Ring gap shapes include square cut, angle cut, tite joint, step cut, hook step and mitre step. Early steam engines used

280-435: A hemp packing to seal the combustion chamber, which caused high frictional resistance and did not provide a very effective seal. The first use of a piston ring in the cylinders of a steam engine appears in 1825 by Neil Snodgrass , a Glasgow engineer and mill-owner, for use in his own machines. This used springs to keep the seal steam-tight. From use within the mill this was experimented on the steamer "Caledonia" which plied

320-406: A hot to a cold reservoir. The mechanism of operation of the engine can be described by the laws of quantum mechanics . Quantum refrigerators are devices that consume power with the purpose to pump heat from a cold to a hot reservoir. In a reciprocating quantum heat engine, the working medium is a quantum system such as spin systems or a harmonic oscillator. The Carnot cycle and Otto cycle are

360-454: A large number of unusual varieties of piston engines that have various claimed advantages, many of which see little if any current use: Piston ring A piston ring is a metallic split ring that is attached to the outer diameter of a piston in an internal combustion engine or steam engine . The main functions of piston rings in engines are: Most piston rings are made from cast iron or steel . Piston rings are designed to seal

400-403: A reciprocating engine is proportional to the volume of the combined pistons' displacement. A seal must be made between the sliding piston and the walls of the cylinder so that the high pressure gas above the piston does not leak past it and reduce the efficiency of the engine. This seal is usually provided by one or more piston rings . These are rings made of a hard metal, and are sprung into

440-480: A sequence of strokes that admit and remove gases to and from the cylinder. These operations are repeated cyclically and an engine is said to be 2-stroke , 4-stroke or 6-stroke depending on the number of strokes it takes to complete a cycle. The most common type is 4-stroke, which has following cycles. The reciprocating engine developed in Europe during the 18th century, first as the atmospheric engine then later as

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480-543: A split in it does not exert an even pressure on the cylinder walls once installed. The revised piston ring was manufactured to an out-of-round shape, so that it would exert even pressure once installed in the cylinder. An 1855 patent documented this change. The switch to metallic piston rings dramatically reduced the frictional resistance, the leakage of steam, and the mass of the piston, leading to significant increases in power and efficiency and longer maintenance intervals. Piston rings are subject to wear as they move up and down

520-412: Is difficult and has been a driving force to improvements in the quality of motor oil . The oil must survive high temperatures and harsh conditions with a high-speed sliding contact. Lubrication is particularly difficult as the rings have an oscillating motion rather than continuous rotation (such as in a bearing journal). At the limits of piston movement, the ring stops and reverses direction. This disrupts

560-433: Is inside a cylinder , into which a gas is introduced, either already under pressure (e.g. steam engine ), or heated inside the cylinder either by ignition of a fuel air mixture ( internal combustion engine ) or by contact with a hot heat exchanger in the cylinder ( Stirling engine ). The hot gases expand, pushing the piston to the bottom of the cylinder. This position is also known as the bottom dead center (BDC), or where

600-586: Is not to be confused with fuel efficiency , since high efficiency often requires a lean fuel-air ratio, and thus lower power density. A modern high-performance car engine makes in excess of 75 kW/L (1.65 hp/in ). Reciprocating engines that are powered by compressed air, steam or other hot gases are still used in some applications such as to drive many modern torpedoes or as pollution-free motive power. Most steam-driven applications use steam turbines , which are more efficient than piston engines. The French-designed FlowAIR vehicles use compressed air stored in

640-412: Is not true of every reciprocating engine), although power and fuel consumption are affected by many factors outside of engine displacement. Reciprocating engines can be characterized by their specific power , which is typically given in kilowatts per litre of engine displacement (in the U.S. also horsepower per cubic inch). The result offers an approximation of the peak power output of an engine. This

680-394: Is the fictitious pressure which would produce the same amount of net work that was produced during the power stroke cycle. This is shown by: where A p {\displaystyle A_{p}} is the total piston area of the engine, S {\displaystyle S} is the stroke length of the pistons, and V d {\displaystyle V_{d}}

720-459: Is the ratio of the diameter of the piston, or " bore ", to the length of travel within the cylinder, or "stroke". If this is around 1 the engine is said to be "square". If it is greater than 1, i.e. the bore is larger than the stroke, it is "oversquare". If it is less than 1, i.e. the stroke is larger than the bore, it is "undersquare". Cylinders may be aligned in line , in a V configuration , horizontally opposite each other, or radially around

760-425: Is the total displacement volume of the engine. Therefore: Whichever engine with the larger value of MEP produces more net work per cycle and performs more efficiently. In steam engines and internal combustion engines, valves are required to allow the entry and exit of gases at the correct times in the piston's cycle. These are worked by cams, eccentrics or cranks driven by the shaft of the engine. Early designs used

800-423: Is then fed through one or more, increasingly larger bore cylinders successively, to extract power from the steam at increasingly lower pressures. These engines are called compound engines . Aside from looking at the power that the engine can produce, the mean effective pressure (MEP), can also be used in comparing the power output and performance of reciprocating engines of the same size. The mean effective pressure

840-452: The D slide valve but this has been largely superseded by piston valve or poppet valve designs. In steam engines the point in the piston cycle at which the steam inlet valve closes is called the cutoff and this can often be controlled to adjust the torque supplied by the engine and improve efficiency. In some steam engines, the action of the valves can be replaced by an oscillating cylinder . Internal combustion engines operate through

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880-458: The Gareloch . The modern design of a metallic split-ring was invented by John Ramsbottom in the 1850s. Ramsbottom's initial design in 1852 was a circular shape, however these wore unevenly and were not successful. In 1854, a revised design was claimed to have a lifespan of up to 4,000 mi (6,437 km). This was based on the discovery that a perfectly round (prior to installation) ring with

920-470: The steam engine . These were followed by the Stirling engine and internal combustion engine in the 19th century. Today the most common form of reciprocating engine is the internal combustion engine running on the combustion of petrol , diesel , liquefied petroleum gas (LPG) or compressed natural gas (CNG) and used to power motor vehicles and engine power plants . One notable reciprocating engine from

960-555: The Cessna 310's units, while its wings were from the Cessna 414 . The 340's primary selling feature was its spacious, pressurized cabin, the first in a light twin. Work on the 340 began in 1969, and the first aircraft was delivered in 1971, behind schedule because one of the prototypes crashed during flight testing in 1970. The early models have two turbocharged Continental TSIO-520-K engines with 285 hp (214 kW) each. Starting in 1976,

1000-483: The World War II era was the 28-cylinder, 3,500  hp (2,600 kW) Pratt & Whitney R-4360 Wasp Major radial engine. It powered the last generation of large piston-engined planes before jet engines and turboprops took over from 1944 onward. It had a total engine capacity of 71.5 L (4,360 cu in), and a high power-to-weight ratio . The largest reciprocating engine in production at present, but not

1040-403: The combustion chamber. The bottom ring—known as the oil control ring —is primarily for controlling the supply of oil to the cylinder wall, in order to lubricate the piston skirt and the oil control rings. The compression rings in an automotive engine typically have a rectangular or keystone shaped cross-section. The upper compression ring typically has a barrel profile for the periphery, while

1080-470: The crankshaft. Opposed-piston engines put two pistons working at opposite ends of the same cylinder and this has been extended into triangular arrangements such as the Napier Deltic . Some designs have set the cylinders in motion around the shaft, such as the rotary engine . In some steam engines, the cylinders may be of varying size with the smallest bore cylinder working the highest pressure steam. This

1120-455: The cylinder bore, due to their own inherent load and due to the gas load acting on the ring. To minimize this, they are made of wear-resistant materials, such as cast iron and steel, and are coated or treated to enhance the wear resistance. Coatings used in modern motorcycles include chromium , nitride , or ceramic coating made by plasma deposition or physical vapour deposition (PVD). Most modern diesel engines have top rings coated with

1160-506: The cylinder by this stroke . The exception is the Stirling engine , which repeatedly heats and cools the same sealed quantity of gas. The stroke is simply the distance between the TDC and the BDC, or the greatest distance that the piston can travel in one direction. In some designs the piston may be powered in both directions in the cylinder, in which case it is said to be double-acting . In most types,

1200-535: The cylinder. Rings binding in the piston, usually due to a build-up of either combustion products or a breakdown of the lubricating oil, can cause engine failure and is a common cause of failure for diesel engines. Sealing is often achieved by multiple rings, each with their own function, using a metal-on-metal sliding contact. Most pistons have at least two piston rings per cylinder. Automotive piston engines typically have three rings per cylinder. The top two rings—known as compression rings —are primarily for sealing

1240-491: The engines were upgraded to the more powerful Continental TSIO-520-NB engines of 310 hp (233 kW). This variant is known as the 340A and it also features smaller 75.5-inch (1,920 mm) diameter propellers to reduce noise and meet ICAO Annex 16 noise requirements. The Cessna 335 was marketed as a low-priced, non-pressurized, version powered by 300 hp (225 kW) Continental TSIO-520-EB engines. The prototype 335 made its maiden flight on December 5, 1978, with

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1280-450: The first production aircraft flying in 1979. It was not a market success, with only 64 built by the time production ended in 1980. The 340 was more successful and remained in production until 1984 with 1287 built. Data from Jane's All The World's Aircraft 1980–81 General characteristics Performance Aircraft of comparable role, configuration, and era Piston engine There may be one or more pistons. Each piston

1320-402: The gap between the piston and the cylinder wall. If this gap were too small, thermal expansion of the piston could mean the piston seizes in the cylinder, causing serious damage to the engine. On the other hand, a large gap would cause insufficient sealing of the piston rings against the cylinder walls, resulting in excessive blow-by (combustion gases entering the crankcase) and less pressure on

1360-588: The largest ever built, is the Wärtsilä-Sulzer RTA96-C turbocharged two-stroke diesel engine of 2006 built by Wärtsilä . It is used to power the largest modern container ships such as the Emma Mærsk . It is five stories high (13.5 m or 44 ft), 27 m (89 ft) long, and weighs over 2,300 metric tons (2,535 short tons ; 2,264 long tons ) in its largest 14 cylinders version producing more than 84.42 MW (113,209 bhp). Each cylinder has

1400-416: The linear movement of the piston is converted to a rotating movement via a connecting rod and a crankshaft or by a swashplate or other suitable mechanism. A flywheel is often used to ensure smooth rotation or to store energy to carry the engine through an un-powered part of the cycle. The more cylinders a reciprocating engine has, generally, the more vibration-free (smoothly) it can operate. The power of

1440-404: The lower compression ring typically has a taper napier facing. Some engines also use a taper facing for the top ring, and simple plain-faced rings were used in the past. Oil control rings are typically made from either a single piece of cast iron, multiple pieces of steel, or steel/iron with a helical spring backing to create the tension required for a close seal. Cast iron oil rings and rings with

1480-421: The normal oil wedge effect of a hydrodynamic bearing , reducing the effectiveness of the lubrication. Rings are also sprung to increase the contact force and to maintain a close seal. The spring force is provided by either the stiffness of the ring itself or by a separate spring behind the seal ring. It is important that rings float freely in their grooves within the piston, so that they can stay in contact with

1520-410: The ones most studied. The quantum versions obey the laws of thermodynamics . In addition, these models can justify the assumptions of endoreversible thermodynamics . A theoretical study has shown that it is possible and practical to build a reciprocating engine that is composed of a single oscillating atom. This is an area for future research and could have applications in nanotechnology . There are

1560-423: The piston forms the largest volume in the cylinder. The piston is returned to the cylinder top (top dead center) (TDC) by a flywheel , the power from other pistons connected to the same shaft or (in a double acting cylinder ) by the same process acting on the other side of the piston. This is where the piston forms the smallest volume in the cylinder. In most types the expanded or " exhausted " gases are removed from

1600-443: The piston, reducing the power output of the engine. The sliding motion of the piston ring inside the cylinder wall causes friction losses for the engine. The friction caused by piston rings is approximately 24% of the total mechanical friction losses for the engine. The design of the piston rings is therefore a compromise between minimising friction while achieving good sealing and an acceptable lifespan. Lubrication of piston rings

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