Abandoned Prototype Engines | Ducati’s Roads Not Taken

By Aaron Frank, Photography by Phil Aynsley

Two Strokes
Like nearly every motorcycle manufacturer in the late ‘60s and early ‘70s, Ducati experimented extensively with two-stroke technology as a means to increase production and reduce costs. Two examples of its two-stroke attempts are shown here. Very little is known (or remembered) about the horizontally oriented 50cc single, except that it was apparently built in 1975 and probably intended to power a moped of some sort. The internal cooling fan is a novel technical solution. The 125cc, dual-plug, piston-port-induction single was Ducati’s entrée into the booming motocross market, an area where the firm had virtually no experience. A prototype version is shown here; the production version appeared in 1975 first to power the Regolarita, then later in 1977, the more successful Six-Days model. Ducati built its last two-stroke off-road bike in 1979.

Ever since the Apollo cruiser experiment in the early 1960s, Taglioni was fascinated by V-fours. In 1976, he picked up where the Apollo project left off by designing a liquid-cooled, 90-degree V-four with belt-driven, single overhead cams and two-valve desmo heads. Both 750 and 1000cc versions were built, but the design was shelved after water-cooling was deemed too complicated and cumbersome for production. A third generation V-four design, devised in 1978, consisted of essentially two air-cooled, 500cc Pantah engines siamesed so the front cylinders were separated to allow airflow to reach the rear cylinders—but adequate cooling still remained a problem. The fourth-generation V-four, dating from 1981, incorporated a dry clutch and oil cooling to help keep the rear cylinders at the proper operating temperature. With a quartet of 40mm Dell’Orto carbs, mild cams, and mufflers, this 994cc engine made an impressive 104 bhp on the engine dyno; with an open exhaust and more aggressive cams, it eventually produced 131 bhp. Taglioni saw potential for as much as 150 bhp with further tuning and the addition of fuel injection, but the V-four development budget dried up after Cagiva purchased Ducati and shifted all resources to developing the Desmoquattro engine that would eventually form the foundation for Ducati’s present success.

Supercharged Pantah
Experiments with forced induction were all the rage in the early ‘80s, and Ducati wasn’t about to be left out. While all four Japanese manufacturers entered production with turbocharged motorcycles, Taglioni—never one to copy another manufacturer—experimented with supercharging instead. Since a supercharger boosts power immediately without any lag like turbo bikes suffer from, Taglioni deemed supercharging a better solution for motorcycle applications.

Starting with a 350cc version of the Pantah V-twin created for the Cagiva Elefant, Taglioni reversed the rear cylinder head and attached a small centrifugal supercharger to the left side of the engine, driven by a belt run directly off the crank. The supercharger fed dual Bing CV carbs. The supercharged motor showed some promise on the test bench in 1985, but by that time the trend for forced induction had already passed and the project was abandoned.

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