Misplaced Pages

#170829

28-598: The Aisin AW TF-8# SC series is a 6-speed automatic transmission designed for use in transverse engine applications produced by Aisin Seiki . It is built in Anjō , Japan, and is also called TF-80SC (AWF21), AF40-6, AM6, AW6A-EL and TF-81SC (AF21). All-wheel drive transfer cases can be fitted to the AWTF-80 SC. A conventional 5-pinion planetary gearset and a compound Ravigneaux gearset

56-496: A car of its size. Coupled to the much greater amount of interior space afforded by the layout (the entire drivetrain only took up 20% of the car's length), this made the Mini a genuine alternative to the conventional small family car. This design reached its peak starting with Dante Giacosa 's elaboration of it for Fiat . He connected the engine to its gearbox by a shaft and set the differential off-center so that it could be connected to

84-483: A larger overall powertrain unit but this was not essential in the type of cars Giacosa proposed. In return such cars would be easier to service and repair and benefit from greater refinement and lower noise levels. Fiat was cautiously accepting of Giacosa's proposal and decided to experiment without risking damage to the image of its popular Fiat-branded cars. Thus the Autobianchi Primula emerged—a car marketed under

112-412: A less crucial nameplate, for which it was an entry into a whole new class of vehicles. The key to Giacosa's design was a compact concentric clutch release mechanism using a hydraulic piston mounted inside a hollow gearbox input shaft, thus doing away with the traditional external clutch lever and release arm and the internal clutch thrust bearing. This allowed the powertrain to be short enough to fit across

140-471: A longitudinal "T-drive" configuration became common in the 1960s. Transverse engines were also used in the British Leyland Atlantean , in many transit buses, and in nearly all modern double decker buses . They have also been widely used by Scania , MAN , Volvo and Renault 's bus divisions. Engines may be placed in two main positions within the motor car: Space allowed for engines within

168-404: A standstill, significantly closing the fuel efficiency gap between automatic and manual transmissions . To reduce external wiring as well as to provide a constant environment for the transmission control module (TCM), it is located inside the transmission housing. Gear shifting is managed by a computer program that oversees a clutch-to-clutch actuation that allows one clutch engage the instant

196-627: Is a supermini economy car manufactured between 1964 and 1970 by the Italian automaker Autobianchi , partly owned by and later a subsidiary of the Fiat Group . The Primula was a prototype for Fiat's rack and pinion steering and is widely known for its innovative Dante Giacosa -designed front-wheel drive , transverse engine layout — that would be later popularized by the Fiat 128 to ultimately become an industry-standard front drive layout. The Primula

224-643: Is a larger front crumple zone . Transverse engines have also been widely used in buses. In the United States, they were offered in the early 1930s by Twin Coach and used with limited success in Dwight Austin's Pickwick Nite-Coach. Transverse bus engines first appeared widely in the Yellow Coach 719, using Dwight Austin's V-drive; they continued in common use until the 1990s, though shorter V-configuration engines in

252-498: Is combined in a Lepelletier gear mechanism , to reduce both the size and weight. It was first realized in 2000 with the 6HP from ZF Friedrichshafen . Like all transmissions realized with Lepelletier transmissions, the AWTF-80 SC also dispenses with the use of the direct gear ratio, making it one of the very few automatic transmission concepts without such a ratio. It also has the capability to achieve torque converter lock-up on all 6 forward gears, and disengage it completely when at

280-514: The 1100/1300 series built in Italy by Innocenti . These larger models did not require the transmission-in-sump arrangement for the purposes of space utilization (as on the Mini) but retained it for design and parts commonality. Fiat's chief designer, Dante Giacosa , recognized the potential of the concept and sought ways to improve on it - namely by removing the transmission from the sump. This would produce

308-511: The British Motor Corporation's Mini , launched in 1959. That car had its transmission integrated into the engine's oil sump, producing a very compact drivetrain for use on a small car. However the Mini had significant transmission problems early in its production run and the arrangement had poor refinement, high noise levels and was awkward to service. The early issues were resolved and the concept spread to larger BMC products, notably

SECTION 10

#1732858285171

336-538: The Lancia Beta - the issue at the time in a transverse installation of a twin-cam head being the arrangement of the exhaust manifold of the necessarily cross-flow head). Unlike contemporaneous BMC and Peugeot models, which had the transmission in the oil sump , the Primula had its manual transmission placed end-on, above the differential . The Primula also featured disc brakes on all four wheels, uncommon in small cars of

364-524: The Lancia Montecarlo , Noble M12 , Toyota MR2 , Pontiac Fiero , and first-generation Honda NSX using such a powertrain design. The Land Rover LR2 Freelander , along with all Volvo models from 1998 on (including V8 models), employ a transversely-mounted engine in order to increase passenger space inside the vehicle. This has also allowed for improved safety in a frontal impact, due to more longitudinal engine compartment space being created. The result

392-482: The Saab 92 , in 1947. The arrangement was also used for Borgward 's Goliath and Hansa brand cars. The East German -built Trabant , which appeared in 1957, also had a transverse mounted two stroke engine, and this design was kept until the end of production, in 1991. However, it was with Alec Issigonis 's Mini , introduced by the British Motor Corporation in 1959, that the design gained acclaim. Issigonis incorporated

420-452: The 1960s, are said to have "transverse" engines, while motorcycles with a V-twin mounted with its crankshaft perpendicular to the direction of travel, e.g. most Ducatis since the 1970s and most Harley-Davidsons , are said to have "longitudinal" engines. This convention uses the longest horizontal dimension (length or width) of the engine as its reference axis instead of the crankshaft. Autobianchi Primula The Autobianchi Primula

448-416: The Mini, but this proved to be no disadvantage. This layout, still in use today, also provided superior refinement, easier repair and was better-suited to adopting five-speed transmissions than the original Issigonis in-sump design. The Lamborghini Miura used a transverse mid-mounted 4.0-litre V12 . This configuration was unheard of in 1965, but became more common in the following decades, with cars such as

476-430: The Primula's engine bay while allowing for the required steering angles and the determined overall width. With the transmission mounted end-on to the engine and the final drive therefore offset from the car's centre line, the Primula had unequal-length driveshafts. Initially, the Primula was fitted with the 1221 cc engine from the Fiat 1100 D (for the coupé it was uprated to 65 hp (48 kW)), but in 1968 it

504-404: The Primula, all Fiat Group passenger cars were rear-wheel drive ; the larger models followed the classic FR layout (front engine powering the rear axle), and small cars were rear-engined . Meanwhile, a practical concept emerged, namely the front-wheel drive layout with the engine mounted transversely , which allowed for very efficient space utilization. This arrangement had been popularised by

532-417: The car's transmission into the engine's sump , producing a drivetrain unit narrow enough to install transversely in a car only 4 feet (1.2 m) wide. While previous DKW and Saab cars used small, unrefined air-cooled two-stroke engines with poor performance, the gearbox-in-sump arrangement meant that an 848 cc four-cylinder water-cooled engine could be fitted to the Mini, providing strong performance for

560-481: The clutch from the previous gear disengages. When idling and with the foot brake depressed neutral gear is selected automatically. This helps to reduce internal temperatures and improve the fuel economy. Transverse engine The Critchley light car , made by the Daimler Motor Company in 1899, had a transverse engine with belt drive to the rear axle. The first successful transverse-engine cars were

588-463: The front wheel wells is commonly limited to the following: The description of the orientation of V-twin and flat-twin motorcycle engines sometimes differs from the convention as stated above. Motorcycles with a V-twin engine mounted with its crankshaft parallel to the direction of travel, e.g. the AJS S3 V-twin , Indian 841 , Victoria Bergmeister , Honda CX series and several Moto Guzzis since

SECTION 20

#1732858285171

616-484: The gearbox more easily. The half shafts from the differential to the wheels therefore differed in length, which would have made the car's steering asymmetrical were it not for their torsional stiffness being made the same. Giacosa's layout was first used in the Autobianchi Primula in 1964 and later in the popular Fiat 128 . With the gearbox mounted separately to the engine, these cars were by necessity larger than

644-452: The gearbox), with a "dead" axle at the rear. The Primula is thus a car design of far greater significance than is often realised, as its design influence spread, far beyond even the mainstream high volume Fiats such as the 128 and the 127 of the late 1960s which used its driveline layout combined with MacPherson struts (which also allowed space for the gearbox); to every front wheel drive transverse engined car in production today. The Primula

672-482: The time. The Primula's particular configuration of front wheel drive and transverse engine, but with a gearbox on the end of the engine, ingenious Fiat-designed clutch release mechanism and unequal length drive shafts, rather than a gearbox in the sump like the Mini, has become universal among front-wheel-drive cars. The suspension used a single wishbone and upper transverse leaf spring at the front (which eliminated an upper suspension arm pivot and thus allowed space for

700-520: The two-cylinder DKW F1 series of cars, which first appeared in 1931. During WWII, transverse engines were developed for armored vehicles, with the Soviet T-44 and T-54/T-55 tanks being equipped with transverse engines to save space within the hull. The T-54/55 eventually became the most produced tank in history. After the Second World War , Saab used the configuration in their first model,

728-554: Was favorably received in the marketplace and came second in the 1965 European Car of the Year awards, after another front-wheel drive car, the Austin 1800 . This convinced Fiat to develop the drive concept further. In 1969 the first Fiat with a front-mounted transverse engine, the Fiat 128 , was launched, along with two new front-wheel drive Autobianchis: the Autobianchi A112 , smaller than

756-553: Was originally available with two or four doors, with or without a rear hatchback, referred to in Italian as " berlina ". Beginning in 1965, Autobianchi offered a coupé model, a more spacious 2-door fastback designed by Carrozzeria Touring . The Primula was manufactured in the Autobianchi factory in Desio , with production reaching approximately 75,000 before ending in 1970. Prior to

784-403: Was replaced with Fiat 124 engines—the berlinas received the 1197 cc 60 hp (45 kW) engine from the standard versions, while the coupé was fitted with the more powerful 1438 cc 70 hp (52 kW) unit. All engines used in the Primula had overhead valves (OHV)—the later twin cam derivative of the 1438 cc unit was not used in any Autobianchi (Fiat did use it later in

#170829