Ducati Bipantah

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Ducati Bipantah
Overview
Manufacturer Ducati
Production prototype only
Combustion chamber
Configuration 90° V4 petrol engine
Displacement 994 cc (60.7 cu in)
Cylinder bore 78.0 mm (3.07 in)
Piston stroke 52.0 mm (2.05 in)
Cylinder block alloy Cast aluminium alloy
Cylinder head alloy Cast aluminium alloy
Valvetrain Desmodromic valve, 2-valves per cyl.
Combustion
Fuel system 4 Dell'Orto 40mm carburettors
Fuel type Petrol/Gasoline
Oil system wet sump
Cooling system Air-Oil cooling
Output
Power output from 105 PS (77.2 kW; 103.6 bhp) @ 9,500 rpm to 132 PS (97 kW; 130 bhp) @ 11,000 rpm (according to engine tuning)
Dimensions
Dry weight 98 kg
Chronology
Predecessor Ducati Apollo
Successor Ducati Desmosedici

Ducati Bipantah is an internal combustion engine made by Italian motocycle manufacturer Ducati in 1981. Designed by Pierluigi Mengoli under Fabio Taglioni's supervision, it has four cylinders and it is ideally formed by coupling two Ducati Pantah V2 engines. It remained at prototype stage and gave very good performances during dyno-tests, but the project came on halt in late 1982, when VM Motori, which owned Ducati in those days, decided not to build the bike that would have been powered by such engine.[1]

History[edit]

Ducati technical director Fabio Taglioni desired to launch a whole new family of Ducati motorbikes to provide the manufacturer a solid position on markets, with reasonable production figures. At the beginning of the eighties world motorcycle sales were decreasing and public was losing interest on Ducati V-twins models, so Taglioni thought that a new brand new project would be the best choice, but it had to be different from Japanese models:[1] first he conceived a 90° V-4, a wooden-metal model of which was realized in 1980,[2] then he ordered to build another 90° V-4 engine, but with a "L" layout,[3] which prototype was built in 1981, one year earlier than the launch of the very innovative 750cc V-4 Honda VF.
BMW motorcycle division managers took the same technical/commercial direction with their new in-line four cylinder engine for K100: they wanted to produce something different from Japanese manufacturers, who were moving to smaller 750 cc engines, and relocate their bikes in a higher range.[1] VM Motori, which owned Ducati since 1978, had different plans: instead of investing money for a new range of bikes, the wanted to turn down the Borgo Panigale factory into a simple engine provider for other motorcycle manufacturer, so in late 1982 they told Taglioni and his men to stop working on the new Bipantah engine and on the bike they were designing around it.[1]
In those days inside Ducati plant diesel VM engines were produced and Pantah engines were provided to Cagiva for its bigger bikes: high cost of industrialization for a new engine and new bikes that would probably lead to low selling figures scared VM Motori managers and Castiglioni brothers from Cagiva,[1] who bought Ducati in May 1985. New owners decided to start new investments in order to compete with Japanese firms and, after long technical discussions, they preferred Desmoquattro over Bipantah, because the first could be easily installed on the existing models.[4]

Technical overview[edit]

Name is self-explanatory: Bipantah engine was born by coupling side by side two 500cc L-twin Ducati Pantah engines, sharing the same crankshaft and with a SOHC on each cylinder bank, to form a 1000cc 90° V-four.[1]

This project embedded all Taglioni's technical beliefs and evolved from his dissertation written in 1948 that concerned a 250 cc 90° V4 engine: Bipantah was the most "oversquare" engine he designed (78mm bore x 52mm stroke = 994cc displacement), in order to reduce overall length and height for a better accommodation inside the frame, but in spite of this it was only 100 mm wider than a "single" Pantah.[1] Rear cylinders were bolted almost vertically to the crankcase, with front ones were almost orizontal, this because they were tilted 20° backwards to provide room for front wheel to move during compression under brake. They were also widely finned because Taglioni preferred air cooling for thermodinamical, weight and size reasons.[1]

Other engine features were desmodromic valves, timing belts, two valves per cylinder (Taglioni did not love multi-valve), two-segment pistons (to reduce friction), a bearing type single-piece crankshaft with coupled connecting rods and four 40mm Dell'Orto carburettors installed on long inlet manifolds between the cylinder banks.[1]

Designer dyno-tested the engine and claimed that Bipantah produced 105 PS (77.2 kW; 103.6 bhp) @ 9,500 rpm on the wheel with a significative thrust from 3,000 rpm in road legal camshaft/muffler configuration, while it produced 132 PS (97 kW; 130 bhp) @ 11,000 rpm (with thrust from 6,000 rpm) in racing configuration, with an expected power of 150 PS (110 kW; 148 bhp) if electronic fuel injection would have replaced carburettors.[1]

References[edit]

  1. ^ a b c d e f g h i j "Bipantah! - Ducati's other V-four". www.motorcyclistonline.com. April 2009. Retrieved August 22, 2012. 
  2. ^ Phil Aynsley (June 2007). "Phil Aynsley Photography > Bikes > Ducati > Other Models > 1980 1000 Bi-Pantah". www.philaphoto.com. Retrieved August 29, 2012. 
  3. ^ Phil Aynsley (June 2007). "Phil Aynsley Photography > Bikes > Ducati > Other Models > 1982 1000 BiPantah". www.philaphoto.com. Retrieved August 29, 2012. 
  4. ^ Claudio Falanga (January 1998). "NEL NOME DEL QUATTRO VALVOLE" [In the name of the Four Valves]. Mondo Ducati (in italian) (nr.5). Retrieved August 28, 2012. 

Bibliography[edit]

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