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Tappet
A tappet is most commonly a component in an internal combustion engine which converts the rotating motion of the camshaft into linear motion of the valves, either directly or indirectly. An earlier use of the term was for part of the valve gear in beam engines beginning in 1715. The term is also used for components in pneumatic cylinders and weaving loom. __TOC__ Beam engines The first recorded use of the term tappet is as part of the valve gear in the 1715 Newcomen engine, an early form of steam engine. Early versions of the Newcomen engines from 1712 had manually operated valves, but by 1715 this repetitive task had been automated through the use of tappets. The beam of the engine had a vertical 'plug rod' hung from it, alongside the cylinder. Adjustable blocks or 'tappets' were attached to this rod and as the beam moved up and down, the tappets pressed against long levers or 'horns' attached to the engine's valves, working the cycle of steam and injection water val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Combustion Engine
An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine, the expansion of the high- temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. The force is typically applied to pistons ( piston engine), turbine blades ( gas turbine), a rotor (Wankel engine), or a nozzle ( jet engine). This force moves the component over a distance, transforming chemical energy into kinetic energy which is used to propel, move or power whatever the engine is attached to. This replaced the external combustion engine for applications where the weight or size of an engine was more important. The first commercially successful internal combustion engine was created by Étienne Lenoir around 1860, and the first modern internal combustion eng ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocker Arm
In the context of an internal combustion engine, a rocker arm is a valvetrain component that typically transfers the motion of a pushrod to the corresponding intake/exhaust 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 at the contact point. Overview In the typical use-case of an overhead valve (pushrod) engine, the camshaft at the bottom of the engine pushes the pushrod upwards. The top of the pushrod presses upwards on one side of the rocker arm (located at the top of the engine), which causes the rocker arm to rotate. This rotation causes the other end of the rocker arm to press downwards on the top of the valve, which opens the valve by moving it downwards. A ''roller rocker'' is a rocker arm that uses needle bearings (or a single bearing ball in older engines) at the contact point between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pushrod
A valvetrain or valve train 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 gasses 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: The camshaft and the valves are located in the engine block below the combustion chamber. * Overhead valve engine: The camshaft remains in the block, however the valves are located in the cylinder head above the combustion chamber. * Overhead camshaft engine: The valves and camshaft(s) are in the cylinder head above the combustion chamber. Components The valvetrain consists of all the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Tappet
A hydraulic tappet, also known as a hydraulic valve lifter or hydraulic lash adjuster, is a device for maintaining zero valve clearance in an internal combustion engine. Conventional solid valve lifters require regular adjusting to maintain a small clearance between the valve and its rocker or cam follower. This space prevents the parts from binding as they expand with the engine's heat, but can also lead to noisy operation and increased wear as the parts rattle against one another until they reach operating temperature. The hydraulic lifter was designed to compensate for this small tolerance, allowing the valve train to operate with zero clearance—leading to quieter operation, longer engine life, and eliminating the need for periodic adjustment of valve clearance. The hydraulic lifter, situated between the camshaft and each engine's valve, is a hollow steel cylinder encasing an internal piston. This piston is held at the outer limit of its travel with a strong spring. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pushrod2
A valvetrain or valve train 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 gasses 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: The camshaft and the valves are located in the engine block below the combustion chamber. * Overhead valve engine: The camshaft remains in the block, however the valves are located in the cylinder head above the combustion chamber. * Overhead camshaft engine: The valves and camshaft(s) are in the cylinder head above the combustion chamber. Components The valvetrain consists of all the compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ford Pinto Engine
The Ford Pinto engine was the unofficial name for a four-cylinder internal combustion engine built by Ford Europe. In Ford sales literature, it was referred to as the EAO or OHC engine and because it was designed to the metric system, it was sometimes called the " metric engine". The internal Ford codename for the unit was the T88-series engine. European Ford service literature refers to it as the Taunus In-Line engine (hence the TL codenames). In North America it was known as the Lima In-Line (LL), or simply the Lima engine due to its being manufactured at Lima Engine in Lima, Ohio. It was used in many European Ford cars and was exported to the United States to be used in the Ford Pinto, a successful subcompact car of the 1970s, hence the name which is used most often for the unit. In Britain, it is commonly used in many kit cars and hot rods, especially in the 2-litre size. Pinto OHC (TL) In Europe, the Pinto OHC was introduced in 1970 to replace the Essex V4 used in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crossflow Cylinder Head
A crossflow cylinder head is a cylinder head that features the intake and exhaust ports on opposite sides. The gases can be thought to flow across the head. This is in contrast to reverse-flow cylinder head designs that have the ports on the same side. Crossflow heads use overhead valves, but these can be actuated either by overhead camshafts, or by a valve-train, which has the camshafts in the cylinder block, and actuates the valves with push rods and rockers. File:Culasse.gif , Crossflow cylinder head, with twin overhead cams File:Overhead camshaft with rockers (Autocar Handbook, 13th ed, 1935).jpg, Cutaway view of the overhead camshaft, rockers and valves of a crossflow cylinder head File:4-Stroke-Engine.gif, Cross-section of a four-stroke engine showing the flow of gases across the cylinder head from the inlet port on the right to the exhaust port on the left, via the combustion chamber Advantages A crossflow head gives better performance than a Reverse-flow cylinder head ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overhead Camshaft Engine
An overhead camshaft (OHC) engine is a piston engine where 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 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; however an O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engine Block
In an internal combustion engine, the engine block is the structure which contains the cylinders and other components. In an early automotive engine, the engine block consisted of just the cylinder block, to which a separate crankcase was attached. Modern engine blocks typically have the crankcase integrated with the cylinder block as a single component. Engine blocks often also include elements such as coolant passages and oil galleries. The term "cylinder block" is often used interchangeably with "engine block", although technically, the block of a modern engine (i.e. multiple cylinders integrated with another component) would be classified as a monobloc. __TOC__ Construction The main structure of an engine typically consists of the cylinders, coolant passages, oil galleries, crankcase, and cylinder head(s). The first production engines of the 1880s to 1920s usually used separate components for each of these elements, which were bolted together during engine assembly. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pushrod Engine
An overhead valve (OHV) engine, sometimes called a ''pushrod engine'', is a piston engine whose valves are located in the cylinder head above the combustion chamber. This contrasts with earlier flathead 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. Some early intake-over-exhaust engines used a hybrid design combining elements of both side-valves and overhead valves. History Predecessors The first internal combustion engines were based on steam engines and therefore used slide valves. This was the case for the first Otto engine, which was first succes ... [...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-1950s 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), th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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