|
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), though some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-cylinder T-head Engine (Autocar Handbook, 13th Ed, 1935)
A single-cylinder engine, sometimes called a thumper, is a piston engine with one cylinder. This engine is often used for motorcycles, motor scooters, go-karts, all-terrain vehicles, radio-controlled vehicles, portable tools and garden machinery (such as lawnmowers, cultivators, and string trimmers). Single-cylinder engines are made both as 4-strokes and 2-strokes. Characteristics Compared with multi-cylinder engines, single-cylinder engines are usually simpler and compact. Due to the greater potential for airflow around all sides of the cylinder, air cooling is often more effective for single cylinder engines than multi-cylinder engines. This reduces the weight and complexity of air-cooled single-cylinder engines, compared with liquid-cooled engines. Drawbacks of single-cylinder engines include a more pulsating power delivery through each cycle and higher levels of vibration. The uneven power delivery means that often a single-cylinder engine requires a heavier flywheel than ... [...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] |
Volumetric Efficiency
Volumetric efficiency (VE) in internal combustion engine engineering is defined as the ratio of the mass density of the air-fuel mixture drawn into the cylinder at atmospheric pressure (during the intake stroke) to the mass density of the same volume of air in the intake manifold. The term is also used in other engineering contexts, such as hydraulic pumps and electronic components. Internal combustion engines Volumetric efficiency in an internal combustion engine design refers to the efficiency with which the engine can move the ''charge'' of fuel and air into and out of the cylinders. It also denotes the ratio of air volume drawn into the cylinder to the cylinder's swept volume. More specifically, volumetric efficiency is a ratio (or percentage) of the mass of air and fuel that is trapped by the cylinder during induction divided by the mass that would occupy the displaced volume if the air density in the cylinder were equal to the ambient air density. The flow restrictions in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Shock
Thermal shock is a type of rapidly transient mechanical load. By definition, it is a mechanical load caused by a rapid change of temperature of a certain point. It can be also extended to the case of a thermal gradient, which makes different parts of an object expand by different amounts. This differential expansion can be more directly understood in terms of strain, than in terms of stress, as it is shown in the following. At some point, this stress can exceed the tensile strength of the material, causing a crack to form. If nothing stops this crack from propagating through the material, it will cause the object's structure to fail. Failure due to thermal shock can be prevented by: # Reducing the thermal gradient seen by the object, by changing its temperature more slowly or increasing the material's thermal conductivity # Reducing the material's coefficient of thermal expansion # Increasing its strength # Introducing built-in compressive stress, as for example in tempered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Cycle
An Otto cycle is an idealized thermodynamic cycle that describes the functioning of a typical spark ignition piston engine. It is the thermodynamic cycle most commonly found in automobile engines. The Otto cycle is a description of what happens to a gas as it is subjected to changes of pressure, temperature, volume, addition of heat, and removal of heat. The gas that is subjected to those changes is called the system. The system, in this case, is defined to be the fluid (gas) within the cylinder. By describing the changes that take place within the system, it will also describe in inverse, the system's effect on the environment. In the case of the Otto cycle, the effect will be to produce enough net work from the system so as to propel an automobile and its occupants in the environment. The Otto cycle is constructed from: :Top and bottom of the loop: a pair of quasi-parallel and isentropic processes (frictionless, adiabatic reversible). :Left and right sides of the loop: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between those layers. Turbulence is commonly observed in everyday phenomena such as surf, fast flowing rivers, billowing storm clouds, or smoke from a chimney, and most fluid flows occurring in nature or created in engineering applications are turbulent. Turbulence is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the damping effect of the fluid's viscosity. For this reason turbulence is commonly realized in low viscosity fluids. In general terms, in turbulent flow, unsteady vortices appear of many sizes which interact with each other, consequently drag due to friction effects increases. This increases the energy needed to pump fluid through a pipe. The onset of turbulence can be predicted by the dimensionless Rey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squish (piston Engine)
Squish is an effect in internal combustion engines which creates sudden turbulence of the air-fuel mixture as the piston approaches top dead centre (TDC)."The Combustion Chamber" Retrieved 16 June 2013. In an engine designed to use the squish effect, at top dead centre the piston crown comes very close (typically less than 1 mm) to the cylinder head. The gases are suddenly "squished" out within the , creating turbulence which promotes thorough air-fuel mixing, a factor beneficial to efficient . Squish effect may be found in |
Sport Motorcycle
A sport bike (sports motorcycle, or sports bike) is a motorcycle designed and optimized for speed, acceleration, braking, and cornering on asphalt concrete race tracks and roads. They are mainly designed for performance at the expense of comfort, Fuel economy in automobiles, fuel economy, and storage in comparison with Types of motorcycles#Standard, other motorcycles. Sport bikes can be and are typically equipped with Motorcycle fairing, fairings and a windscreen to deflect wind from the rider to improve aerodynamics. Soichiro Honda wrote in the owner's manual of the 1959 Honda CB92 Benly Super Sport that, "Primarily, essentials of the motorcycle consists in the speed and the thrill," while ''Cycle World''s Kevin Cameron (journalist), Kevin Cameron says that, "A sportbike is a motorcycle whose enjoyment consists mainly from its ability to perform on all types of paved highway – its cornering ability, its handling, its thrilling acceleration and braking power, even (dare I say ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sports Car
A sports car is a car designed with an emphasis on dynamic performance, such as handling, acceleration, top speed, the thrill of driving and racing capability. Sports cars originated in Europe in the early 1900s and are currently produced by many manufacturers around the world. Definition Definitions of sports cars often relate to how the car design is optimised for dynamic performance, without any specific minimum requirements; both a Triumph Spitfire and Ferrari 488 Pista can be considered sports cars, despite vastly different levels of performance. Broader definitions of sports cars include cars "in which performance takes precedence over carrying capacity", or that emphasise the "thrill of driving" or are marketed "using the excitement of speed and the glamour of the (race)track" However, other people have more specific definitions, such as "must be a two-seater or a 2+2 seater" or a car with two seats only. In the United Kingdom, early recorded usage of the "sports car" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luxury Car
A luxury car is a car that provides increased levels of comfort, equipment, amenities, quality, performance, and associated status compared to moderately priced cars. The term is subjective and reflects both the qualities of the car and the brand image of its manufacturer. Luxury brands rank above ''premium brands'', though there is no fixed demarcation between the two. Traditionally, most luxury cars were large vehicles, though smaller sports-oriented models were always produced. "Compact" luxury vehicles such as hatchbacks, and off-road capable sport utility vehicles, are relatively modern trends. Classification standards Several car classification schemes include a luxury category, such as: * Australia: Since the year 2000, the Federal Government's luxury car tax applies to new vehicles over a certain purchase price, with higher thresholds applying for cars considered as fuel efficient. As of 2019, the thresholds were approximately AU$66,000 (US$,000) for normal cars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. Common examples of aircraft include airplanes, helicopters, airships (including blimps), gliders, paramotors, and hot air balloons. The human activity that surrounds aircraft is called ''aviation''. The science of aviation, including designing and building aircraft, is called '' aeronautics.'' Crewed aircraft are flown by an onboard pilot, but unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as lift type, aircraft propulsion, usage and others. History Flying model craft and stories of manned flight go back many centuries; however, the first manned ascent — and safe descent — in modern times took place by larger hot-air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Top Dead Centre
In a reciprocating engine, the dead centre is the position of a piston in which it is either farthest from, or nearest to, the crankshaft. The former is known as Top Dead Centre (TDC) while the latter is known as Bottom Dead Centre (BDC). More generally, the dead centre is any position of a crank where the applied force is straight along its axis, meaning no turning force can be applied. Many sorts of machines are crank driven, including unicycles, bicycles, tricycles, various types of machine presses, gasoline engines, diesel engines, steam locomotives, and other steam engines. Crank-driven machines rely on the energy stored in a flywheel to overcome the dead centre, or are designed, in the case of multi-cylinder engines, so that dead centres can never exist on all cranks at the same time. A steam locomotive is an example of the latter, the connecting rods being arranged such that the dead centre for each cylinder occurs out of phase with the other one (or more) cylin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Flathead Engine")
.JPG "Click for more on -> Single-cylinder T-head Engine (Autocar Handbook, 13th Ed, 1935)")
.jpg "Click for more on -> Sport Motorcycle")
