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OHC
An overhead camshaft (OHC) engine is a piston engine in which the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion chamber in the engine block. ''Single overhead camshaft'' (SOHC) engines have one camshaft per cylinder bank, bank of cylinders. ''Dual overhead camshaft'' (DOHC, also known as "twin-cam") engines have two camshafts per bank. The first production car to use a DOHC engine was built in 1910. Use of DOHC engines slowly increased from the 1940s, leading to many automobiles by the early 2000s using DOHC engines. Design In an OHC engine, the camshaft is located at the top of the engine, above the combustion chamber. This contrasts the earlier overhead valve engine (OHV) and flathead engine configurations, where the camshaft is located down in the engine block. The valves in both OHC and OHV engines are located above the combustion chamber; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cylinder Head
In a piston engine, the cylinder head sits above the cylinders, forming the roof of the combustion chamber. In sidevalve engines the head is a simple plate of metal containing the spark plugs and possibly heat dissipation fins. In more modern overhead valve and overhead camshaft engines, the head is a more complicated metal block that also contains the inlet and exhaust passages, and often coolant passages, valvetrain components, and fuel injectors. Number of cylinder heads A piston engine typically has one cylinder head per bank of cylinders. Most modern engines with a "straight" (inline) layout today use a single cylinder head that serves all the cylinders. Engines with a "V" layout or "flat" layout typically use two cylinder heads (one for each cylinder bank), however a small number of 'narrow-angle' V engines (such as the Volkswagen VR5 and VR6 engines) use a single cylinder head spanning the two banks. Most radial engines have one head for each cylind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quad 4 Engine
The Quad 4 is a family of straight-four engines produced by General Motors' Oldsmobile division. Several Overhead camshaft engine#Dual overhead camshaft (DOHC), double overhead camshaft (DOHC) versions were produced between 1987 and 2002, and one Overhead camshaft engine#Single overhead camshaft (SOHC), single overhead camshaft (SOHC) model was built from 1992 to 1994. History The Quad 4 is the first domestic regular production DOHC four-cylinder engine wholly designed and built by GM, the only similar prior example being the Chevrolet Cosworth Vega, whose DOHC head was designed by Cosworth in England. In addition to the 2.3-liter DOHC Quad 4s, there was also a short-lived 2.3-liter SOHC variant called the "Quad OHC", available from 1992 to 1994, and the 2.4-liter Twin Cam, available from 1996 to 2002. The Quad 4 was originally expected to debut in 1987, but was delayed for one year. From as early as 1988, Oldsmobile announced that a high-output "HO" Quad&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overhead Valve Engines
An overhead valve engine, abbreviated (OHV) and sometimes called a pushrod engine, is a piston engine whose valves are located in the cylinder head above the combustion chamber. This contrasts with flathead (or "sidevalve") engines, where the valves were located below the combustion chamber in the engine block. Although an overhead camshaft (OHC) engine also has overhead valves, the common usage of the term "overhead valve engine" is limited to engines where the camshaft is located in the engine block. In these traditional OHV engines, the motion of the camshaft is transferred using pushrods (hence the term "pushrod engine") and rocker arms to operate the valves at the top of the engine. However, some designs have the camshaft in the cylinder head but still sit below or alongside the valves (the Ford CVH and Opel CIH are good examples), so they can essentially be considered overhead valve designs. Some early intake-over-exhaust engines used a hybrid design combining elements ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overhead Valve Engine
An overhead valve engine, abbreviated (OHV) and sometimes called a pushrod engine, is a piston engine whose valves are located in the cylinder head above the combustion chamber. This contrasts with flathead (or "sidevalve") engines, where the valves were located below the combustion chamber in the engine block. Although an overhead camshaft (OHC) engine also has overhead valves, the common usage of the term "overhead valve engine" is limited to engines where the camshaft is located in the engine block. In these traditional OHV engines, the motion of the camshaft is transferred using pushrods (hence the term "pushrod engine") and rocker arms to operate the valves at the top of the engine. However, some designs have the camshaft in the cylinder head but still sit below or alongside the valves (the Ford CVH and Opel CIH are good examples), so they can essentially be considered overhead valve designs. Some early intake-over-exhaust engines used a hybrid design combining eleme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camshaft
A camshaft is a shaft that contains a row of pointed cams in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines (to operate the intake and exhaust valves), mechanically controlled ignition systems and early electric motor speed controllers. Camshafts in piston engines are usually made from steel or cast iron, and the shape of the cams greatly affects the engine's characteristics. History Trip hammers are one of the early uses of a form of cam to convert rotating motion, e.g. from a waterwheel, into the reciprocating motion of a hammer used in forging or to pound grain. Evidence for these exists back to the Han dynasty in China, and they were widespread by the medieval period. Camshafts were first described by Ismail al-Jazari in 1206. Once the rotative version of the steam engine was developed in the late 18th century, the operation of the valve gear was usually by an eccentric, which turned the rotation of the crankshaft i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lotus-Ford Twin Cam
The Lotus-Ford Twin Cam is an Straight-four engine, inline-four petrol engine developed by Lotus Cars, Lotus for the 1962 Lotus Elan. A few early examples displaced 1.5 litres, but the majority were 1.55-litre (1557cc) engines. It used a Ford Motor Company, Ford Ford Kent engine, 116E iron cylinder block and a new aluminium cylinder head with Overhead camshaft#Dual overhead camshaft, dual overhead camshafts. The Twin Cam was used in a variety of vehicles until Lotus stopped production in 1973. It was succeeded by the Lotus 907 engine. History For the Lotus Elan, Lotus founder Colin Chapman wanted to find a less expensive engine than the costly all-alloy Coventry Climax#FW, Coventry Climax FWE used in the original Lotus Elite. He felt that basing his new power-plant on an engine built in large volumes would keep costs down. Chapman initially chose the Ford Kent engine, Ford 105E inline four used in the Ford Anglia#Anglia 105E (1959–1968), Ford Anglia as the basis of this new en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inline-four Engine
A straight-four engine (also referred to as an inline-four engine) is a four-cylinder piston engine where cylinders are arranged in a line along a common crankshaft. The majority of automotive four-cylinder engines use a straight-four layout (with the exceptions of the flat-four engines produced by Subaru and Porsche) and the layout is also very common in motorcycles and other machinery. Therefore the term "four-cylinder engine" is usually synonymous with straight-four engines. When a straight-four engine is installed at an inclined angle (instead of with the cylinders oriented vertically), it is sometimes called a slant-four. Between 2005 and 2008, the proportion of new vehicles sold in the United States with four-cylinder engines rose from 30% to 47%. By the 2020 model year, the share for light-duty vehicles had risen to 59%. Design A four-stroke straight-four engine always has a cylinder on its power stroke, unlike engines with fewer cylinders where there is no power st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pushrod
A valvetrain is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) into the combustion chamber, while the exhaust valves control the flow of spent exhaust gases out of the combustion chamber once combustion is completed. Layout The valvetrain layout is largely dependent on the location of the camshaft. The common valvetrain configurations for piston engines, in order from oldest to newest, are: * Flathead engine: A single camshaft and the valves are located in the engine block below the cylinder or cylinder bank. * Overhead valve engine: A single camshaft remains in the block below the cylinder(s), however the valves are located in the cylinder head above the combustion chamber. * Overhead camshaft engine: Both the valves and one or more camshafts are located in the cylinder head above the cylinders or cylinder banks. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triumph Slant-four Engine
The Triumph slant-four is an inline-four engine, inline four-cylinder petrol automobile, car engine developed by the Triumph Motor Company. It first appeared in 1968 in the Saab 99. The first Triumph model to use the engine did not appear until 1972. With an original capacity of 1.7 L, displacement grew over time to 2.0 L. Triumph production ended in 1981. History In 1963 Triumph's Chief Engine Designer Lewis Dawtrey presented the results of his analysis of future engine technology trends and Triumph's anticipated needs. After evaluating Wankel engine, rotary, Flat engine, horizontally opposed, V4 engine, V4 and V6 engine, V6 configurations Dawtrey recommended an Overhead camshaft, OHC engine family composed of both Inline-four engine, Inline-4 and V8 engine, V8 engines that could be built with the same tooling. The new range would be built in capacities of 1.5 L to 3.0 L, allowing it to replace both the four-cylinder Standard SC engine, Standard SC and deriva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfa Romeo Twin Cam Engine
The Alfa Romeo Twin Cam engine is an all-alloy inline-four engine series produced by Alfa Romeo from 1954 to 1994. In Italian it is known as the "bialbero" ("twin-shaft"), and has also been nicknamed the "Nord" (North) engine in reference to its being built in Portello, Milan (later Arese, close to Milan), in the North of Italy and to distinguish it from the Alfa Romeo Boxer engine built in the South (Sud) for the Alfasud. History The Twin Cam's predecessor appeared in the 1950 Alfa Romeo 1900 and was an under-square inline four cylinder with a cast-iron block, an aluminium alloy crossflow cylinder head with double overhead cams and a 90° included angle between intake and exhaust valves. Development of that engine was overseen by Orazio Satta Puliga who would also helm development of its successor. The 1952 Disco Volante had a 2-litre DOHC four cylinder engine with an aluminium block and sleeves, but this seems to have been a custom version of the 1900 engine rather tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocker Arm
A rocker arm is a valvetrain component that typically transfers the motion of a pushrod in an overhead valve engine, overhead valve internal combustion engine to the corresponding intake/exhaust poppet valve, valve. Rocker arms in automobiles are typically made from stamped steel, or aluminum in higher-revving applications. Some rocker arms (called ''roller rockers'') include a bearing at the contact point, to reduce wear and friction there. Overview The most common use of a rocker arm is to transfer the up and down motion of a pushrod in an overhead valve engine, overhead valve (OHV) internal combustion engine to the corresponding intake/exhaust poppet valve, valve. In an OHV engine the camshaft located within the engine block below the cylinder bank(s) pushes the pushrod upwards. The top of the pushrod presses upwards on one side of the rocker arm located at the top of the cylinder head, which causes the rocker arm to pivot downward on the top of the valve, opening it. To redu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flathead Engine
A flathead engine, also known as a sidevalve engine''American Rodder'', 6/94, pp.45 & 93. or valve-in-block engine, is an internal combustion engine with its poppet valves contained within the engine block, instead of in the cylinder head, as in an overhead valve engine. Flatheads were widely used internationally by automobile manufacturers from the late 1890s until the mid-1960s but were replaced by more efficient overhead valve and overhead camshaft engines. They are currently experiencing a revival in low-revving aero-engines such as the D-Motor. The side-valve design The valve gear comprises a camshaft sited low in the cylinder block which operates the poppet valves via tappets and short pushrods (or sometimes with no pushrods at all). The flathead system obviates the need for further valvetrain components such as lengthy pushrods, rocker arms, overhead valves or overhead camshafts. The sidevalves are typically adjacent, sited on one side of the cylinder(s), though ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
