A transmission is a machine in a power transmission system, which provides controlled application of the power. The term transmission refers to the gearbox that uses gears and gear trains to provide speed and torque conversions from a rotating power source to another device. In British English, the term transmission refers to the whole drivetrain, including clutch, prop shaft and final drive shafts. In American English, the term refers more to the gearbox alone, detailed usage differs; the most common use is in motor vehicles, where the transmission adapts the output of the internal combustion engine to the drive wheels. Such engines need to operate at a high rotational speed, inappropriate for starting and slower travel; the transmission reduces the higher engine speed to the slower wheel speed, increasing torque in the process. Transmissions are used on pedal bicycles, fixed machines, where different rotational speeds and torques are adapted. A transmission has multiple gear ratios with the ability to switch between them as speed varies.
This switching may be done automatically. Directional control may be provided. Single-ratio transmissions exist, which change the speed and torque of motor output. In motor vehicles, the transmission is connected to the engine crankshaft via a flywheel or clutch or fluid coupling because internal combustion engines cannot run below a particular speed; the output of the transmission is transmitted via the driveshaft to one or more differentials, which drives the wheels. While a differential may provide gear reduction, its primary purpose is to permit the wheels at either end of an axle to rotate at different speeds as it changes the direction of rotation. Conventional gear/belt transmissions are not the only mechanism for speed/torque adaptation. Alternative mechanisms include power transformation. Hybrid configurations exist. Automatic transmissions use a valve body to shift gears using fluid pressures in response to speed and throttle input. Early transmissions included the right-angle drives and other gearing in windmills, horse-powered devices, steam engines, in support of pumping and hoisting.
Most modern gearboxes are used to increase torque while reducing the speed of a prime mover output shaft. This means that the output shaft of a gearbox rotates at a slower rate than the input shaft, this reduction in speed produces a mechanical advantage, increasing torque. A gearbox can be set up to do the opposite and provide an increase in shaft speed with a reduction of torque; some of the simplest gearboxes change the physical rotational direction of power transmission. Many typical automobile transmissions include the ability to select one of several gear ratios. In this case, most of the gear ratios are used to slow down the output speed of the engine and increase torque. However, the highest gears may be "overdrive" types. Gearboxes have found use in a wide variety of different—often stationary—applications, such as wind turbines. Transmissions are used in agricultural, construction and automotive equipment. In addition to ordinary transmission equipped with gears, such equipment makes extensive use of the hydrostatic drive and electrical adjustable-speed drives.
The simplest transmissions called gearboxes to reflect their simplicity, provide gear reduction, sometimes in conjunction with a right-angle change in direction of the shaft. These are used on PTO-powered agricultural equipment, since the axial PTO shaft is at odds with the usual need for the driven shaft, either vertical, or horizontally extending from one side of the implement to another. More complex equipment, such as silage choppers and snowblowers, have drives with outputs in more than one direction; the gearbox in a wind turbine converts the slow, high-torque rotation of the turbine into much faster rotation of the electrical generator. These are more complicated than the PTO gearboxes in farm equipment, they weigh several tons and contain three stages to achieve an overall gear ratio from 40:1 to over 100:1, depending on the size of the turbine. The first stage of the gearbox is a planetary gear, for compactness, to distribute the enormous torque of the turbine over more teeth of the low-speed shaft.
Durability of these gearboxes has been a serious problem for a long time. Regardless of where they are used, these simple transmissions all share an important feature: the gear ratio cannot be changed during use, it is fixed at the time. For transmission types that overcome this issue, see Continuously variable transmission known as CVT. Many applications require the availability of multiple gear ratios; this is to ease the starting and stopping of a mechanical system, though another important need is that of maintaining good fuel efficiency. The need for a transmission in an automobile is a consequence of the characteristics of the internal combustion engine. Eng
Wire wheels, wire-spoked wheels, tension-spoked wheels, or "suspension" wheels are wheels whose rims connect to their hubs by wire spokes. Although these wires are stiffer than a typical wire rope, they function mechanically the same as tensioned flexible wires, keeping the rim true while supporting applied loads; the term suspension wheel should not be confused with vehicle suspension. Wire wheels are still used on many motorcycles, they were invented by aeronautical engineer George Cayley in 1808. Although Cayley first proposed wire wheels, he did not apply for a patent; the first patent for wire wheels was issued to Theodore Jones of London, England on October 11, 1826. Eugène Meyer of Paris, France was the first person to receive, in 1869, a patent for wire wheels on bicycles. Bicycle wheels were not strong enough for cars until the development of tangentially spoked wheels, they became well established in the bicycle and motor tricycle world but were not common on cars until around 1907. This was encouraged by the Rudge-Whitworth patented detachable and interchangeable wheels designed by John Pugh.
These wheels owed their resistance to braking and accelerative stresses to their two inner rows of tangential spokes. An outer row of radial spokes gave; these wheels were dished so that steering pivot pins might lie as near as possible to the center-line of the tires. Their second feature was that they were detachable being mounted on splined false hubs. A process of assembling wire wheels is described as wheelbuilding. From the earliest days automobiles used either wire wheels or heavy wooden or pressed steel spoked artillery type; the development of the quick detachable hubs of either Rudge-Whitworth or Riley design did much to popularise wire wheels and incidentally led to the fitting of "spare wheels". After their wooden spoked artillery wheels proved inadequate many US manufacturers paid John Pugh of Rudge-Whitworth royalties to manufacture wire wheels using his patents. Artillery wheels fell out of favour in the late 1920s and the development of the cheaper pressed steel wheels by Joseph Sankey replaced wire wheels wherever the premium price of wire wheels was not justified by their weight saving.
A sample of cars first riding on wire wheels Before 1960, sports/racing cars had Rudge-Whitworth wire wheels center-locking equipped with splined hubs and a quick-release "knockoff" locking cap that could be unscrewed by striking a wing of the nut with a special alloy mallet or "knockoff hammer". Some jurisdictions, including West Germany, prohibited eared hubcaps; some manufacturers preferred to hold the wheel on the splined hub by capping with a single conventional unwinged nut requiring a special large spanner. In the 1960s lighter cast alloy wheels became usual—at first with splined hubs and knock-off caps—and now predominate. New versions of wire wheels are still made but with standard hub bolt patterns covered by a center cap to fit without adapters. At one time, motorcycles used wire wheels built up from separate components, except for dirtbikes, they are now used for their retro appearance; the first commercially successful use of wired wheels was on bicycles. They were introduced early on in the development of the bicycle, following soon after the adoption of solid rubber tires.
This development marked a major improvement over the older wooden wheels, both in terms of weight and comfort. In England, the engineer William Stanley developed the steel-wired spider wheel in 1849, an improvement over the cumbersome wooden spoked wheels fitted to the tricycles that his employer was making. Bicycle manufacturers build millions of wheels annually, using the common crossed-spoke patterns whose crossings of adjacent spokes are governed by the number of spokes in the wheel. Wheelbuilders of racing teams and in good bicycle shops build wheels to other patterns such as two-cross, one-cross, or no-cross. Many of these patterns have been used for more than 100 years, it is claimed that crossed patterns have more strength and stability while irregular patterns are art forms and have little structural merit. In the 1980s, cast wheels with 5 or 6 rigid spokes began to appear in the Olympic Games and professional racing: these have advantages in specialized applications, such as time trials, but wire-spoked wheels are used for most purposes.
The reaction to a radial load of a well-tensioned wire spoked wheel, such as by a rider sitting on a bicycle, is that the wheel flattens near the ground contact area. The rest of the wheel remains circular; the tension of all the spokes does not increase significantly. Instead, only the spokes directly under the hub decrease their tension; the issue of how best to describe this situation is debated. Some authors conclude from this that the hub "stands" on those spokes below it that experience a reduction in tension though the spokes below the hub exert no upward force on the hub and can be replaced by chains without much changing the physics of the wheel. Other authors conclude that the hub "hangs" from those spokes above it that exert an upward force on the hub, that have higher tension than the spokes below the hub, which pull down on the hub. Despite being composed of thin and flexible spokes, wire wheels are radially stiff and provide little suspension compliance compared to high-pressure bicycle tires.
Astounding.org.uk, an analysis of the deflection of wire wheels. Duke.edu, an analysis of the deflection of wire wheels
A clutch is a mechanical device which engages and disengages power transmission from driving shaft to driven shaft. In the simplest application, clutches disconnect two rotating shafts. In these devices, one shaft is attached to an engine or other power unit while the other shaft provides output power for work. While the motions involved are rotary, linear clutches are possible. In a torque-controlled drill, for instance, one shaft is driven by a motor and the other drives a drill chuck; the clutch connects the two shafts so they may be locked together and spin at the same speed, locked together but spinning at different speeds, or unlocked and spinning at different speeds. The vast majority of clutches rely on frictional forces for their operation; the purpose of friction clutches is to connect a moving member to another, moving at a different speed or stationary to synchronize the speeds, and/or to transmit power. As little slippage as possible between the two members is desired. Various materials have been used including asbestos in the past.
Modern clutches use a compound organic resin with copper wire facing or a ceramic material. Ceramic materials are used in heavy applications such as racing or heavy-duty hauling, though the harder ceramic materials increase flywheel and pressure plate wear. In the case of "wet" clutches, composite paper materials are common. Since these "wet" clutches use an oil bath or flow-through cooling method for keeping the disc pack lubricated and cooled little wear is seen when using composite paper materials. Friction-disc clutches are classified as push type or pull type depending on the location of the pressure plate fulcrum points. In a pull-type clutch, the action of pressing the pedal pulls the release bearing, pulling on the diaphragm spring and disengaging the vehicle drive; the opposite is true with a push type, the release bearing is pushed into the clutch disengaging the vehicle drive. In this instance, the release bearing can be known as a thrust bearing. A clutch damper is a device. In automotive applications, this is provided by a mechanism in the clutch disc centres.
In addition to the damped disc centres, which reduce driveline vibration, pre-dampers may be used to reduce gear rattle at idle by changing the natural frequency of the disc. These weaker springs are compressed by the radial vibrations of an idling engine, they are compressed and no longer in use once the main damper springs take up drive. Mercedes truck examples: A clamp load of 33 kN is normal for a single plate 430; the 400 Twin application offers a clamp load of a mere 23 kN. Bursts speeds are around 5,000 rpm with the weakest point being the facing rivet. Modern clutch development focuses its attention on the simplification of the overall assembly and/or manufacturing method. For example, drive straps are now employed to transfer torque as well as lift the pressure plate upon disengagement of vehicle drive. With regard to the manufacture of diaphragm springs, heat treatment is crucial. Laser welding is becoming more common as a method of attaching the drive plate to the disc ring with the laser being between 2-3KW and a feed rate 1m/minute.
This type of clutch has several driving members interleaved or "stacked" with several driven members. It is used in racing cars including Formula 1, IndyCar, World Rally and most club racing. Multiplate clutches see much use in drag racing, which requires the best acceleration possible, is notorious for the abuse the clutch is subjected to. Thus, they can be found in motorcycles, in automatic transmissions and in some diesel locomotives with mechanical transmissions, it is used in some electronically controlled all-wheel drive systems as well as in some transfer cases. They can be found in some heavy machinery such as tanks and AFV's and earthmoving equipment, as well as components in certain types of limited slip differentials; the benefit in the case of motorsports is that you can achieve the same total friction force with a much smaller overall diameter. In motorsports vehicles that run at high engine/drivetrain speeds, the smaller diameter reduces rotational inertia, making the drivetrain components accelerate more as well as reducing the velocity of the outer areas of the clutch unit, which could become stressed and fail at the high drivetrain rotational rates achieved in sports such as Formula 1 or drag racing.
In the case of heavy equipment, which deal with high torque forces and drivetrain loads, a single plate clutch of the necessary strength would be too large to package as a component of the driveline. Another, different theme on the multiplate clutch is the clutches used in the fastest classes of drag racing specialized, purpose-built cars such as Top Fuel dragsters or Funny Cars; these cars are so powerful that to attempt a start with a simple clutch would result in complete loss of traction. To avoid this problem, Top Fuel cars use a single, fixed gear ratio, a series of clutches that are engaged one at a time, rather than in unison, progressively allowing more power to the wheels. A single one of these clutch plates can not hold more than a fr
World War I
World War I known as the First World War or the Great War, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. Contemporaneously described as "the war to end all wars", it led to the mobilisation of more than 70 million military personnel, including 60 million Europeans, making it one of the largest wars in history, it is one of the deadliest conflicts in history, with an estimated nine million combatants and seven million civilian deaths as a direct result of the war, while resulting genocides and the 1918 influenza pandemic caused another 50 to 100 million deaths worldwide. On 28 June 1914, Gavrilo Princip, a Bosnian Serb Yugoslav nationalist, assassinated the Austro-Hungarian heir Archduke Franz Ferdinand in Sarajevo, leading to the July Crisis. In response, on 23 July Austria-Hungary issued an ultimatum to Serbia. Serbia's reply failed to satisfy the Austrians, the two moved to a war footing. A network of interlocking alliances enlarged the crisis from a bilateral issue in the Balkans to one involving most of Europe.
By July 1914, the great powers of Europe were divided into two coalitions: the Triple Entente—consisting of France and Britain—and the Triple Alliance of Germany, Austria-Hungary and Italy. Russia felt it necessary to back Serbia and, after Austria-Hungary shelled the Serbian capital of Belgrade on the 28th, partial mobilisation was approved. General Russian mobilisation was announced on the evening of 30 July; when Russia failed to comply, Germany declared war on 1 August in support of Austria-Hungary, with Austria-Hungary following suit on 6th. German strategy for a war on two fronts against France and Russia was to concentrate the bulk of its army in the West to defeat France within four weeks shift forces to the East before Russia could mobilise. On 2 August, Germany demanded free passage through Belgium, an essential element in achieving a quick victory over France; when this was refused, German forces invaded Belgium on 3 August and declared war on France the same day. On 12 August and France declared war on Austria-Hungary.
In November 1914, the Ottoman Empire entered the war on the side of the Alliance, opening fronts in the Caucasus and the Sinai Peninsula. The war was fought in and drew upon each power's colonial empire as well, spreading the conflict to Africa and across the globe; the Entente and its allies would become known as the Allied Powers, while the grouping of Austria-Hungary and their allies would become known as the Central Powers. The German advance into France was halted at the Battle of the Marne and by the end of 1914, the Western Front settled into a battle of attrition, marked by a long series of trench lines that changed little until 1917. In 1915, Italy opened a front in the Alps. Bulgaria joined the Central Powers in 1915 and Greece joined the Allies in 1917, expanding the war in the Balkans; the United States remained neutral, although by doing nothing to prevent the Allies from procuring American supplies whilst the Allied blockade prevented the Germans from doing the same the U. S. became an important supplier of war material to the Allies.
After the sinking of American merchant ships by German submarines, the revelation that the Germans were trying to incite Mexico to make war on the United States, the U. S. declared war on Germany on 6 April 1917. Trained American forces would not begin arriving at the front in large numbers until mid-1918, but the American Expeditionary Force would reach some two million troops. Though Serbia was defeated in 1915, Romania joined the Allied Powers in 1916 only to be defeated in 1917, none of the great powers were knocked out of the war until 1918; the 1917 February Revolution in Russia replaced the Tsarist autocracy with the Provisional Government, but continuing discontent at the cost of the war led to the October Revolution, the creation of the Soviet Socialist Republic, the signing of the Treaty of Brest-Litovsk by the new government in March 1918, ending Russia's involvement in the war. This allowed the transfer of large numbers of German troops from the East to the Western Front, resulting in the German March 1918 Offensive.
This offensive was successful, but the Allies rallied and drove the Germans back in their Hundred Days Offensive. Bulgaria was the first Central Power to sign an armistice—the Armistice of Salonica on 29 September 1918. On 30 October, the Ottoman Empire capitulated. On 4 November, the Austro-Hungarian empire agreed to the Armistice of Villa Giusti after being decisively defeated by Italy in the Battle of Vittorio Veneto. With its allies defeated, revolution at home, the military no longer willing to fight, Kaiser Wilhelm abdicated on 9 November and Germany signed an armistice on 11 November 1918. World War I was a significant turning point in the political, cultural and social climate of the world; the war and its immediate aftermath sparked numerous uprisings. The Big Four (Britain, the United States, It
A drum brake is a brake that uses friction caused by a set of shoes or pads that press outward against a rotating cylinder-shaped part called a brake drum. The term drum brake means a brake in which shoes press on the inner surface of the drum; when shoes press on the outside of the drum, it is called a clasp brake. Where the drum is pinched between two shoes, similar to a conventional disc brake, it is sometimes called a pinch drum brake, though such brakes are rare. A related type called a band brake uses a flexible belt or "band" wrapping around the outside of a drum; the modern automobile drum brake was first used in a car made by Maybach in 1900, although the principle was only patented in 1902 by Louis Renault. He used woven asbestos lining for the drum brake lining, as no alternative dissipated heat like the asbestos lining, though Maybach had used a less sophisticated drum brake. In the first drum brakes and rods or cables operated the shoes mechanically. From the mid-1930s, oil pressure in a small wheel cylinder and pistons operated the brakes, though some vehicles continued with purely mechanical systems for decades.
Some designs have two wheel cylinders. As the shoes in drum brakes wear, brakes required regular manual adjustment until the introduction of self-adjusting drum brakes in the 1950s. Drums are prone to brake fading with repeated use. In 1953, Jaguar fielded three cars equipped with disc brakes at Le Mans, where they won, in large part due to their superior braking over drum-equipped rivals; this spelled the beginning of the crossover of drum brakes to disc brakes in passenger cars. From the 1960s to the 1980s, disc brakes replaced drum brakes on the front wheels of cars. Now all cars use disc brakes on the front wheels, many use disc brakes on all four wheels. In the United States, the Jeep CJ-5 was the final automobile to use front drum brakes when it was phased out in 1984. However, drum brakes are still used for handbrakes, as it has proven difficult to design a disc brake suitable for holding a parked car. Moreover, it is easy to fit a drum handbrake inside a disc brake so that one unit serves as both service brake and handbrake.
Early brake shoes contained asbestos. When working on brake systems of older cars, care must be taken not to inhale any dust present in the brake assembly; the United States Federal Government began to regulate asbestos production, brake manufacturers had to switch to non-asbestos linings. Owners complained of poor braking with the replacements. A majority of daily-driven older vehicles have been fitted with asbestos-free linings. Many other countries limit the use of asbestos in brakes. Drum brake components include the backing plate, brake drum, wheel cylinder, various springs and pins; the backing plate provides a base for the other components. The back plate increases the rigidity of whole set-up, supports the housing, protects it from foreign materials like dust and other road debris, it absorbs the torque from the braking action, and, why back plate is called the "Torque Plate". Since all braking operations exert pressure on the backing plate, it must be strong and wear-resistant. Levers for emergency or parking brakes, automatic brake-shoe adjuster were added in recent years.
The brake drum is made of a special type of cast iron, heat-conductive and wear-resistant. It rotates with the axle; when a driver applies the brakes, the lining pushes radially against the inner surface of the drum, the ensuing friction slows or stops rotation of the wheel and axle, thus the vehicle. This friction generates substantial heat. One wheel cylinder operates the brake on each wheel. Two pistons operate one at each end of the wheel cylinder; the leading shoe is known as the primary shoe. The trailing shoe is known as the secondary shoe. Hydraulic pressure from the master cylinder acts on the piston cup, pushing the pistons toward the shoes, forcing them against the drum; when the driver releases the brakes, the brake shoe springs restore the shoes to their original position. The parts of the wheel cylinder are shown to the right. Brake shoes are made of two pieces of steel welded together; the friction material is either attached with adhesive. The crescent-shaped piece is called the Web and contains holes and slots in different shapes for return springs, hold-down hardware, parking brake linkage and self-adjusting components.
All the application force of the wheel cylinder is applied through the web to the lining table and brake lining. The edge of the lining table has three “V"-shaped notches or tabs on each side called nibs; the nibs rest against the support pads of the backing plate. Each brake assembly has a primary and secondary; the primary shoe is located toward the front of the vehicle and has the lining positioned differently from the secondary shoe. Quite the two shoes are interchangeable, so close inspection for any variation is important. Linings must be resistant to heat and wear and have a high friction coefficient unaffected by fluctuations in temperature and humidity. Materials that make up the brake shoe include, friction modifiers, powdered metal such as lead, brass and other metals that resist heat fade, curing agents and fillers such as rubber chips to reduce brake noise. In the UK two common grades of brake shoe material used to be available. DON 202 was a hig
A monobloc or en bloc engine is an internal-combustion piston engine where some of the major components are formed by casting, as a single integral unit, rather than being assembled later. This has the advantages of improving mechanical stiffness, improving the reliability of the sealing between them. Monobloc techniques date back to the beginnings of the internal combustion engine. Use of the term has changed over time to address the most pressing mechanical problem affecting the engines of its day. There have thus been three distinct uses of the technique: Cylinder head and cylinder Cylinder block Cylinder block and crankcaseIn most cases, any use of the term describes a deliberate single-unit construction, opposed to the more common contemporary practice. Where the monobloc technique has become the norm, the specific term falls from favour, it is now usual and un-noteworthy practice to use monobloc cylinders and crankcases, but a monobloc head would be regarded as peculiar and obsolescent.
The head gasket is the most stressed static seal in an engine and was a source of considerable trouble in early years. The monobloc cylinder head forms both cylinder and head in one unit, thus avoiding the need for a seal. Along with head gasket failure, one of the least reliable parts of the early petrol engine was the exhaust valve, which tended to fail by overheating and burning. A monobloc head could provide good water cooling, thus reduced valve wear, as it could extend the water jacket uninterrupted around both head and cylinder. Engines with gaskets required a metal-to-metal contact face here; the drawback to the monobloc head is that access to the inside of the combustion chamber becomes difficult. Access through the cylinder bore is restricted for machining the valve seats, or for inserting angled valves. An more serious restriction is that for the maintenance task of de-coking and re-grinding the valve seats, a regular task on older engines. Rather than removing the cylinder head from above, the mechanic must now remove pistons, connecting rods and the entire crankshaft from beneath.
One solution to this for side-valve engines was to place a screwed plug directly above each valve, to access the valves through this. The tapered threads of the screwed plug provided a reliable seal. For low-powered engines this was a popular solution for some years, it was difficult to cool this plug. As performance increased, it became important to have better combustion chamber designs with less "dead space". One solution was to place the spark plug in the centre of this plug, which at least made use of the space; however this placed the spark plug further away from the main combustion chamber, leading to long flame paths and slower ignition. During World War I, development of the internal combustion engine progressed enormously. After the war, as civilian car production recommenced, the monobloc cylinder head was required less frequently. Only high-performance cars such as the Leyland Eight of 1920 persisted with it. Bentley and Bugatti were other racing marques who notably adhered to them, through the 1920s and into the 1930s, most famously being used in the purpose-built American Offenhauser straight-four racing engines, first designed and built in the 1930s.
Aircraft engines at this time were beginning to use high supercharging pressures, increasing the stress on their head gaskets. Engines such as the Rolls-Royce Buzzard used monobloc heads for reliability; the last engines to make widespread use of monobloc cylinder heads were large air-cooled aircraft radial engines, such as the Wasp Major. These have individual cylinder barrels, so access as a monobloc is less restricted than on inline engine; as they are of high specific power and require the utmost reliability, the advantages of the monobloc remained attractive. The difficulties of machining, maintaining, a monobloc cylinder head were always a severe drawback to it; as head gaskets became able to handle the heat and pressure necessary, the technique went out of use. It is unknown today, but has found a few "niche" uses, as the technique of monobloc cylinder heads was adopted by the Japanese model engine manufacturer Saito Seisakusho for their glow fueled and spark ignition model four-stroke engines for RC aircraft propulsion needs.
Casting technology at the dawn of the internal combustion engine could reliably cast either large castings, or castings with complex internal cores to allow for water jackets, but not both simultaneously. Most early engines those with more than four cylinders, had their cylinders cast as pairs or triplets of cylinders bolted to a single crankcase; as casting techniques improved, the entire cylinder block of four, six or eight cylinders could be cast as one. This was a simpler construction, thus less expensive to make, the communal water jacket permitted closer spacing between cylinders; this improved the mechanical stiffness of the engine, against bending and the important torsional twist, as cylinder numbers and engine lengths increased. In the context of aircraft engines, the non-monobloc precursor to monobloc cylinders was a construction where the cylinders were cast as individuals, the outer water jacket was applied from copper or steel sheet; this complex construction was expensive, but lightweight, so it was only used for aircraft.
V engines remained with a separate block casting for each bank. The complex ducting required for inlet manifolds between the banks were too complicated to cast otherwise. For economy, a few engi
Alfa Romeo Alfasud
The Alfa Romeo Alfasud was a small family car, manufactured from 1971 to 1989 by Industria Napoletana Costruzioni Autoveicoli Alfa Romeo-Alfasud S.p. A of Italy, a new company owned by Alfa Finmeccanica; the company was based in the southern region of Italy as a part of the labour policy of the government. It is considered one of Alfa Romeo's most successful models, with 893,719 examples sold between 1972 and 1983, plus 121,434 Sprint coupé versions between 1976 and 1989. A common nickname for the car is ’Sud; the car went through two facelifts, the first in 1977 and the second one in 1980. Alfa Romeo had explored building a smaller front wheel drive car in the 1950s but it was not until 1967 that firm plans were laid down for an all-new model to fit in below the existing Alfa Romeo range, it was developed by Austrian Rudolf Hruska, who created a unique engineering package, clothed in a body styled by Giorgetto Giugiaro of ItalDesign. The car was built at a new factory at Pomigliano d'Arco in southern Italy, hence the car's name, Alfa Sud.
January 18, 1968, saw the registration at Naples of a new company named "Industria Napoletana Costruzioni Autoveicoli Alfa Romeo-Alfasud S.p. A.". 90% of the share capital was subscribed by Alfa Romeo and 10% by Finmeccanica, at that time the financial arm of the government controlled IRI. Construction work on the company's new state-sponsored plant at nearby Pomigliano d'Arco began in April 1968, on the site of an aircraft engine factory used by Alfa Romeo during the Second World War; the Alfasud was shown at the Turin Motor Show three years in 1971 and was praised by journalists for its styling. The four-door saloon featured a cutting-edge technology, following the technical scheme experimented in Lancia since 1960 on the Lancia Flavia, that is: a front wheel drive with Boxer of 1,186 cc water-cooled engine with a belt-driven overhead camshaft on each cylinder head, it featured an elaborate suspension setup for a car in its class:. Other unusual features for this size of car were four-wheel disc brakes, rack and pinion steering.
The engine design allowed the Alfasud to have a low bonnet line, making it aerodynamic for its day giving it a low centre of gravity. As a result of these design features, the car had excellent performance for its engine size, levels of road-holding and handling that would not be equalled in its class for another ten years. Despite its two-box shape, a hatchback was not part of the range; some of the controls were unorthodox, the lights, turn indicators, horn and heater fan all being operated by pulling, turning or pushing the two column stalks. In November 1973 the first Alfasud sport model joined the range, the two-door Alfasud ti—. Along with a 5-speed gearbox, it featured a more powerful version of the 1.2 litre engine, brought to 68 PS by adopting a Weber twin-choke carburettor, allowing the small saloon to reach 160 km/h. Quad round halogen headlamps, special wheels, a front body-colour spoiler beneath the bumper and rear black one around the tail distinguished the "ti", while inside there was a three-spoke steering wheel, auxiliary gauges, leatherette/cloth seats, carpets in place of rubber mats.
In 1974, Alfa Romeo launched a more upscale model, the Alfasud SE. The SE was replaced by the Alfasud L model introduced at the Bruxelles Motor Show in January 1975. Recognizable by its bumper overriders and chrome strips on the door sills and on the tail, the Lusso was better appointed than the standard Alfasud, with such features as cloth upholstery, padded dashboard with glove compartment and optional tachometer. A three-door estate model called the Alfasud Giardinetta was introduced in May 1975, with the same equipment of the Alfasud "L"; the Lusso model was produced until 1976, was replaced by the new Alfasud 5m model, the first four-door Alfasud with a five-speed gearbox. Presented at the March 1976 Geneva Motor Show, it was equipped like the Lusso. In September 1976, the Alfasud Sprint coupé was launched. Built on the same platform of the saloon, it featured lower, more angular bodywork, again by Giorgetto Giugiaro, featured a hatchback; the Sprint was powered by a new, more powerful Boxer, stroked from the 1.2 to displace 1,286 cc and develop 76 PS, was paired the five-speed gearbox.
The same 1286 cc engine was fitted into the 2-door saloon, creating the Alfasud ti 1.3, put on sale alongside the "ti" 1.2 in July 1977. In late 1977 the Alfasud Super replaced the range-topping four-door "5m", it was available with both the 1.2- and 1.3-litre engines from the "ti", though both were equipped with a single-choke carburettor. The Super introduced improvements both outside, with new bumpers including large plastic strips, inside, with a revised dashboard, new door cards and two-tone cloth seats. Similar upgrades were applied to the Giardinetta. In May 1978 the Sprint and "ti" got new engines, a 79 PS 1.3 and a 85 PS 1.5, both with a twin-choke carburettor. At the same time the Alfasud ti received cosmetic updates: bumpers from the Super, new rear spoiler on the boot lid, black wheel arch extensions and black front spoiler, was upgraded to the revised interior of the Super; the 1.3 and 1.5 engines were soon made available alongside the 1.2 on the Giardinetta and Super, with a lower output compared to the sport models, due to having a single-choke carburettor.
In 1979 the Sprint was given a double twin-choke carbur