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Page "Crankshaft" ¶ 1
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crankshaft and sometimes
It typically connects to a flywheel and to reduce the pulsation characteristic of the four-stroke cycle, and sometimes a torsional or vibrational damper at the opposite end, to reduce the torsional vibrations often caused along the length of the crankshaft by the cylinders farthest from the output end acting on the torsional elasticity of the metal.
The same basic engine block can be used with different crankshafts, however, to alter the firing order ; for instance, the 90 ° V6 engine configuration, in older days sometimes derived by using six cylinders of a V8 engine with what is basically a shortened version of the V8 crankshaft, produces an engine with an inherent pulsation in the power flow due to the " missing " two cylinders.
A familiar type sometimes seen on small motorcycles is a slotted disk attached to the crankshaft which covers and uncovers an opening in the end of the crankcase, allowing charge to enter during one portion of the cycle.
Typically, the layout has cylinders arranged in two banks on either side of a single crankshaft and is sometimes known as the boxer, or horizontally opposed engine.
The CX series feature a crankshaft configuration aligned longitudinally with the axis of bike, sometimes called a " flying " V-twin, because the cylinders point up on either side of the motorcycle but are not symmetrical.

crankshaft and usually
Large engines are usually multicylinder to reduce pulsations from individual firing strokes, with more than one piston attached to a complex crankshaft.
Though the fiber flow ( local inhomogeneities of the material's chemical composition generated during casting ) doesn ’ t follow the shape of the crankshaft ( which is undesirable ), this is usually not a problem since higher quality steels, which normally are difficult to forge, can be used.
The rotary engine was an early type of internal-combustion engine, usually designed with an odd number of cylinders per row in a radial configuration, in which the crankshaft remained stationary and the entire cylinder block rotated around it.
A V12 engine is a V engine with 12 cylinders mounted on the crankcase in two banks of six cylinders, usually but not always at a 60 ° angle to each other, with all 12 pistons driving a common crankshaft.
A V6 engine is a V engine with six cylinders mounted on the crankcase in two banks of three cylinders, usually set at either a right angle or an acute angle to each other, with all six pistons driving a common crankshaft.
Internal combustion piston engines ( those with more than one cylinder ) are usually arranged so that the cylinders are in lines parallel to the crankshaft.
A few V4 engines have also been produced, usually where an extra-compact engine was required, including some outboard motors with a vertical crankshaft.
The pistons are usually mounted on the crankshaft such that opposing pistons move back and forth in opposite directions at the same time, somewhat like boxing competitors punching their gloves together before a fight, which has led to it being referred to as a boxer engine.
On recent EMS found on modern vehicles, the signal for the tachometer is usually generated from an ECU which derives the information from either the crankshaft or camshaft speed sensor.
# Blade Mounting and Drive System – the blade of a rotary mower is usually mounted directly to the crankshaft of its engine, but it can be propelled by a hydraulic motor or a belt pulley system.
This is usually achieved with a positive displacement blower driven by the crankshaft.
A W18 engine is an eighteen cylinder piston engine which usually has a single crankshaft with three banks of six cylinders arranged in an inverted broad arrow configuration.
An overhead valve ( OHV ) engine, also informally called pushrod engine or I-head engine, is a type of piston engine that places the camshaft within the cylinder block ( usually beside and slightly above the crankshaft in a straight engine or directly above the crankshaft in the V of a V engine ), and uses pushrods or rods to actuate rocker arms above the cylinder head to actuate the valves.
These early minibikes usually had of a power train with a small four-stroke, horizontal crankshaft, flathead engine.
Nevertheless, the area around the crankshaft is still usually called the crankcase.

crankshaft and crank
To convert the reciprocating motion into rotation, the crankshaft has " crank throws " or " crankpins ", additional bearing surfaces whose axis is offset from that of the crank, to which the " big ends " of the connecting rods from each cylinder attach.
The distance the axis of the crank throws from the axis of the crankshaft determines the piston stroke measurement, and thus engine displacement.
The same engine, however, can be made to provide evenly spaced power pulses by using a crankshaft with an individual crank throw for each cylinder, spaced so that the pistons are actually phased 120 ° apart, as in the GM 3800 engine.
While production V8 engines use four crank throws spaced 90 ° apart, high-performance V8 engines often use a " flat " crankshaft with throws spaced 180 ° apart.
The Buick V6 was notable because it introduced the concept of uneven firing, as a result of using the 90 ° cylinder bank angle and shared-crankpin crankshaft design found in the V8 engine ( although the V6 crankshaft does have 3 crank throws set at 120 ° apart, rather than 90 ° apart as found in the V8 ).
Unlike the 60 ° or 90 ° configuration, it allows pairs of pistons to share crank pins in a three-throw crankshaft without requiring flying arms or split crankpins to be even-firing.
Before the advent of the starter motor, engines were started by various methods including wind-up springs, gun powder cylinders, and human-powered techniques such as a removable crank handle which engaged the front of the crankshaft, pulling on an airplane propeller, or pulling a cord that was wound around an open-face pulley.
Even though cranks had an overrun mechanism, when the engine started, the crank could begin to spin along with the crankshaft and potentially strike the person cranking the engine.
On smaller engines the connecting rod links the piston and the crankshaft directly, but this transmits transverse forces to the piston, since the crankpin ( and thus the direction the force is applied ) moves from side to side with the rotary motion of the crank.
Usually, each pair of corresponding pistons from each bank of cylinders share one crank pin on the crankshaft, either by master / slave rods or by two ordinary connecting rods side by side.
With a piston starting its power strokes every 180 degrees of crankshaft rotation, and the crank throws 180 degrees apart, all the pistons must come to complete stop and reverse before the next one can start its power stroke.
In particular, a phenomenon referred to as " crankshaft whip ," caused by the effects of centrifugal force on the crank throws at high engine rpm, could cause physical contact between the connecting rods and crankcase walls, leading to the engine's destruction.
Maximum cylinder pressure is achieved a few crankshaft degrees after the piston passes TDC, so that the increasing pressure can give the piston a hard push when its speed and mechanical advantage on the crank shaft gives the best recovery of force from the expanding gases.
Like the modern crankshaft, Al-Jazari's mechanism consisted of a wheel setting several crank pins into motion, with the wheel's motion being circular and the pins moving back-and-forth in a straight line.
Other systems do away with the distributor as a timing apparatus and use a magnetic crank angle sensor mounted on the crankshaft to trigger the ignition at the proper time.
In a reciprocating piston engine, the connecting rod or conrod connects the piston to the crank or crankshaft.
The new engine was an " L Head " ( AKA flathead ) design, and featured a wider ( 135 degree ) v-angle, twin carburetors, twin fuel pumps, twin distributors, twin water pumps and a nine main bearing crankshaft ( compared to the OHV V-16's five bearing crank ) and produced the same as later versions of the original V-16 with even greater smoothness and endowed the ' 38 -' 40 Sixteens with the swiftest acceleration of any car in the world at the time regardless of weight as well as slightly improved fuel economy over the OHV V-16 cars.
The smaller displacement was achieved with a new crankshaft ( stroke vs. the stroke of the 225 crank ) and connecting rods ( long vs. the rods in the 225 ).
2002 and earlier model year engines featured a one-piece cast nodular iron crankshaft with counterweights present on either side of each crank pin.
The W8 can be imagined as flat plane crank V8 engine combining two narrow-angle ( 15 degree ) V4 engine blocks, mounted juxtaposed at 72 degrees to each other and coupled to one crankshaft.
Because it was derived from Buick's aluminum V8, it has a 90 ° bank between cylinders and an uneven firing pattern due to the crankshaft having only three crank pins set at 120 ° apart, with opposing cylinders ( 1-2, 3-4 and 5-6 ) sharing a crank pin in, as do many V8 engines.

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