Engines The Taglioni designed single cylinder bevel drive OHC engines were of a vertically spilt
unit construction and had alloy
head and alloy
barrels with
austenitic liners.
Ball bearings were used in the
main bearings and
roller bearings for the
big end. Hairspring valve springs were used to close the valves except on the 239 cc models.
Wet sump lubrication was used.
Narrow case The earlier engines were retrospectively known as 'narrow case' after the introduction of the revised 'wide case' engines.
Type A First shown at the
Milan Motorcycle Show in late 1956, the OHC singles were available in 100, 125, 175 and 200 cc variants. Production of the Type A continued until 1961.
Type B With the introduction of the 250 cc Monza and Diana, the engines were revised with improvements to the crankshaft, cylinder head and clutch housings. The Type B engines were available in 125, 160, 200, 250 and 350 cc displacements. In 1964 5 speed gearboxes were fitted.
Wide case In 1968, an improved engine was introduced based on the engines used in the 250SCD and 350SCD racers. It featured rear engine mountings that were three times wider than the front engine mount. Internally the engine had stronger main bearings and big ends, an improved kickstart mechanism and larger capacity sump. The engine continued until production of the OHC stopped in 1974 and was available in 239, 250, 350 and 450 cc versions.
Desmo The wide case engines were also available in desmo versions. Unlike the racing models, the road versions used a single camshaft and used helper valve springs to improve starting and low speed running. Apart from the cylinder head assembly, the desmo and non-desmo engines are the same.
OHC 98 cc Gran Sport Ducati's single overhead-cam 98 cc Gran Sport, designed by Taglioni, became the blueprint for all future Ducati singles. It had an air-cooled cylinder inclined forward 10 degrees from vertical, gear primary drive, wet-sump lubrication, battery ignition and camshaft drive by vertical shaft and bevel gears. This bike came to dominate its class in Italian racing. In 1956 there was a
DOHC 125 cc version of the Gran Sport. In spite of being a government appointed director, Montano was a motorcycle enthusiast and under his direction, Ducati's competitive activities grew.
Fabio Taglioni was chief designer and technical director of Ducati from 1954 to 1989, serving longer than many of the managements that were to follow. The company soon developed a full-fledged racing team. Italians were avid racing fans and would buy bikes built by winners. To acquire a competitive image Ducati needed to race successfully. Taglioni's usual development procedure was to test a motorcycle on the racetrack before releasing it to the public.
125 Desmo Ducati The high RPMs needed to produce competitive power in a small engine generated
valve float, which Taglioni believed could be overcome with
desmodromic valve actuation. The 125 Grand Prix could produce 16 hp at 11,500 rpm, its true rev limit, while the Desmo could crank out 19 hp at 12,500 rpm and could “safely” (bottom end permitting) rev further to 15,000. Big-end life was short at these sorts of revs and new crankshaft bearings were put in for every race.
Desmodromics, were used in the W196 Mercedes-Benz straight-eight Desmo engines that dominated early formula 1 racing. When Mercedes retired from racing, it retired the Mercedes desmo technology, never using it in production models. Taglioni applied it successfully to Ducati motorcycles. As usual, Desmo technology was used first in racing Ducatis and then in Ducati street machines. The 125 Desmo Ducati won its first race at the 1956 Swedish G.P. at Hedemora, lapping all the other cycles, but then its rider, Gianni Degli Antoni, died during the practice for the next race, the Italian G.P. of Monza. That death dealt a severe blow to the Ducati racing program and it was not until 1958 that their team was able to mount a serious challenge to Italy's MV Agusta, and their top rider, former 125 cc world champion, Carlo Ubbiali. In 1958 the Ducati Desmo dominated the racing season and the racing team was soon headed for the World Championship. Unfortunately a mid-season injury to winning Ducati rider Bruno Spaggiani spoilt their run, allowing Ubbiali to narrowly take the title again. Nevertheless, in that season the Desmodromic engine had proved its quality and reliability, in terms of maximizing engine power and as insurance against over-revving damage. These characteristics proved attractive to motorcycle buyers. The 125 Sport became the 125 Monza. There was also the Monza Super, a further improved version with high-compression piston, modified camshaft, a slightly larger SS1 Dell'Orto racing carburettor, and a straight-through exhaust. The Monza Super was British market only. Oxford's Ducati dealer, Kings, was pushing Ducati for a 250 cc machine to compete against British and Japanese motorcycles. Ducati began by building a 250 cc racer. The prototype won most of its races in America, many running in conjunction with 500 cc events. In 1959 Ducati introduced the 200cc Elite and 200SS, which were derived from the very successful 175cc single cylinder shaft driven ohc machine.
Diana The first production Ducati 250 debuted at the Milan Fair in April 1961. It was called the Diana but for some unknown reason was renamed as Daytona in the UK. The 250 was so popular that in 1963 Ducati introduced the Diana Mark 3 Super Sport.
Scrambler The
Scrambler series of singles were made for the US market from 1962 until 1974,
Diana Mark 3 Super Sport This machine first appeared in 1962. It was derived from the production 250s but was considerably tuned and had 5 gears instead of the 4 of its predecessors. Several European magazines tested it and were able to exceed 100 mph, making it by far the fastest production 250 on the market. It was later introduced to the American market where, under the name of Diana Mark 3 Super Sport, it proved again to be the fastest 250 street bike in the world that year. In a carefully monitored
Cycle World track test, the Mark 3 did a standing 1/4 mile in 16.5 seconds with a final speed of 79.5 mph. Its top speed was 104 mph. Even a TD-1 Yamaha racer, tested by
Cycle World that same year, was unable to match the Ducati's top speed and no other comparably sized registrable production bike that year could compete with its performance. Ducati motorcycles were selling well in
North America and other export markets such as Britain, Australia and Germany. In Italy Ducati was doing well, and not just building motorcycles. By 1965, Ducati Meccanica SpA had become the Italian distributor for Standard-Triumph cars and Leyland vans and trucks.
1965 Ducati 350 Sebring In 1965, the first new concept bike arrived. The 350 Sebring was the largest Ducati of the day. Typically, Ducati built a racing 350 first. The 350 class was not common in the United States, so when Ducati team rider Franco Farne went to America to race at Sebring race, he had to race in an event catering to 251-700 cc machines. Despite the larger capacity opposition, he finished 11th overall and, more importantly, won his own class outright. In honour of Farne's victory the new model became the 350 Sebring. (Footnote: It was common for Italian manufacturers of competition cars or motorcycles to attach to the name their products events they have won.) By the mid-1960s, production techniques had advanced to the extent that a road Desmo was now possible. Farne's appeared at the April 1966 Modena meeting, riding a prototype 250 cc machine fitted with an experimental Desmodromic head. In 1967 Roberto Gallina and Gilberto Parlotti raced at Modena on 250 and 350 versions.
Production desmo In 1967, after eight years of development, Ducati introduced its first production Desmodromic engine, a machine that drew as much from the race track as it did from the drawing board, epitomising the engineering concept that “form follows function”. In January, 1968, Ducati announced plans to build and market the
450 cc Mark 3D. The D was for Desmodromic. Early in 1969 the long-awaited Desmo production machine began appearing. The Desmo design in the new engine, had all four closing and opening lobes mounted on the same shaft, similar to the arrangement used in the late fifties W196 Mercedes-Benz Formula 1 cars. The bike was available in Europe in
250 and
350 versions as well as the 450. In 1971, Ducati released a variant for off-road use called the R/T and another street version, the Mark 3 Special, colloquially named the 'Silver Shotgun'. The motorcycling public seemed to feel that it should have been a “real” 500, and it did not sell well in the US, despite the fact that it outperformed many larger capacity motorcycles of its time. Berliner seemed unable to “hit a winner” in its choice of models, or in selling them to a “cubic inch” market. In Britain Vic Camp had recognized that Ducati was an enthusiast's motorcycle and concentrated on a relatively narrow performance-oriented line. By 1967 Berliner was at the brink of financial ruin - and Ducati with it. The
160 Monza Junior was another flop in the U.S. market. The US was buying larger capacity two cylinder motorcycles, and it came to the point where Berliner refused a shipment, citing market saturation, but the grim reality was, they did not have the funds to pay. This shipment was purchased by a speculator named Bill Hannah and the bikes were sold on the UK market at prices that undercut Vic Camp's official imports. In the financial tragedy that followed Montano retired. The only out on offer was a takeover by EFIM, a government holding company. This meant direct government control over day-to-day factory operations via a government-appointed administrator whose independent powers were limited. Ducati's last real off-road, four stroke, competition motorcycles were the 1971
450 R/T and 450 R/S. The RT had a Seeley-style frame that looked stylish, especially when compared to the old style frames on other Ducati singles, but 1971 was a few years too late. Fewer than 400 were made. For many British car and motorcycle companies of the era, government intervention was the guarantee of a lingering death. This did not prove to be so for Ducati. Unlike British manufacturers of the time, Italy's Ducati was successful in re-inventing itself. It did this with a line of larger capacity V-twins, but first it went racing, on 500 cc Desmo GP bikes and the
Ducati 750 Imola Desmo. ==References==