Twin peaks: a history of Ducati's iconic V-twin engine

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This year is a milestone for Ducati’s iconic, Desmodromic V-twin – or ‘L-twin’ as the Italian firm call their 90-degree engine layout.

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Not only does 2021 mark the 50th anniversary of the very first production Ducati L-twin – the 1971 GT750 – it also sadly signifies another nail in the coffin for the desmo V-twin. 

The arrival of the new, cam-driven Multistrada V4 and the 2018 switch from V-twin to V4 power for the Panigale family means the engine that not only characterised modern Ducati but also dominated a generation of motorcycle sport is on borrowed time.

The desmo V-twin, after all, has been at the heart of every Ducati superbike from the original 1974 750 Super Sport to the 2017, 200+bhp 1299 Panigale R, with the MHR900, 851, 916 and more in-between.

Carl Fogarty

The desmo twin was also at the centre of other legendary Ducatis such as the Pantah and Multistrada. It’s hard to imagine bikesport without Paul Smart’s Imola 200 victory, Mike Hailwood’s 1978 TT heroics or Foggy’s four WSB crowns – without the desmo V-twin modern motorcycling simply wouldn’t be the same.

So, there’s more than a little irony to the fact that, had things worked out differently, Ducati may never have begun producing V-twins at all – and gone straight into the V4 layout they are adopting today.

Ducati’s first big Vee was not a twin but the ill-fated 1964 Apollo – a 1260cc V4 conceived to rival Harley-Davidson in the US.

Ducati Apollo

The Apollo was developed at the request of Ducati’s US importers and created by chief designer Fabio Taglioni, who’d pioneered desmodromics on Ducati’s singles in the mid-1950s. However, following the completion and display of two prototypes, government funding was withdrawn and the Apollo project was cancelled.

At the same time it was clear that Ducati were in desperate need of new, bigger, multi-cylinder models. In the late-1960s, the Italian company’s biggest bikes were the bevel-drive, 250, 350 and 450 singles, with desmo versions arriving in 1968.

However, with the arrival of Honda’s four-cylinder CB750 in 1968, Triumph’s three-cylinder Trident and with Ducati struggling to survive, something had to change.

Ducati instructed Taglioni to design a new engine that would lead the firm into a new era. What he came up with was brilliant, yet simple. With fours and triples already spoken for, plus limited resources, Taglioni instead married together two bevel-drive 350cc singles to create the characteristic Ducati L-twin with which we’re so familiar today.

Taglioni’s first drawings were done in March 1970. The new 750cc engine was running by July with a complete prototype ready in August. In October, Ducati decided to re-enter racing to promote the new machine and Taglioni was tasked to also develop a higher performance version with desmodromic heads, along with a shorter-stroke 500 for GP racing.

A very Smart move

Ducati GT 750

In November 1970 the first production L-twin, the 750 GT, was unveiled causing a sensation – so much so that when it went into production in June the following year the factory struggled to produce motors rapidly enough.

However, with the racers suffering teething problems and the GT more tourer than sportsbike, Ducati were still a long way from being considered a superbike brand.

That all changed in 1972. The first Imola 200 race was announced for April modelled on the prestigious Daytona 200 and eligible for the new Formula 750 machines.

Record prize money of $50,000 attracted a packed field from the likes of MV Agusta, Triumph and Kawasaki. And, although Ducati’s new V-twins weren’t fancied, the factory entered seven desmo racers, adding reluctant Brit Paul Smart to their roster at the last minute after Kawasaki pulled out unexpectedly.

And the rest, as they say, is history, with Smart claiming a famous 1-2 for the desmo V-twin with lead rider Bruno Spaggiari and the result not only boosting 750 GT sales but leading to a sportier 750 Sport then, in 1974, a production road version – the ‘racer replica’ desmo 750 Super Sport.

Ducati 750 Super Sport Paul Smart race replica

That bike is today considered the most significant machine in Ducati history. With a silver and blue half fairing and race riding position it was one of the sportiest and most beautiful road bikes ever. While its high-compression engine, race-derived chassis and light weight gave it the performance to match.

From that day forward, the basic desmo L-twin layout became Ducati’s signature – although some were more successful than others. Just 401 1974 ‘round case’ 750 Super Sports were built, for example, before it was replaced by the less popular ‘square case’ version.

In 1974 Ducati had also introduced the 860 GT, enlarged via the use of the 450 singles’ sleeves and pistons and the first L-twin with the controversially restyled ‘square case’ crank cases. These were then used on the 1975 750 Super Sport.

Incidentally, although the ‘round case’ motor was scrapped for the street, it lived on in racing. A change in Ducati management in 1973 led not only to the ‘square case’ engine but also the cancellation of Ducati’s racing activities.

These were instead largely taken on by nearby racing specialists NCR who continued to develop the ‘round case’ engine, famously supplying the NCR 900 on which Hailwood won the 1978 F1 TT.

Desmoquattro dominance

Massimo Bordi

Around the same time, a new kind of Ducati L-twin was being developed. The 500SL Pantah debuted in 1979 as a middleweight designed by Taglioni to replace Ducati’s unsuccessful 1976 350 and 500cc parallel twins.

With belt instead of bevel cam drive and a tubular trellis frame, the Pantah set the template for a new generation of Ducati L-twins. While its racing success, first in 600cc F2 form with Tony Rutter at the TT, then later in 750cc F1 trim, paved the way for what was to come next.

That, of course, was the ‘Desmoquattro’ which powered the 851. The pet project of Taglioni protégé Massimo Bordi, who had actually designed a four-valve desmo back in 1973 for his engineering thesis. The engine, although based on the Pantah, was virtually all-new and characterised by not just four-valve heads but also liquid-cooling and fuel-injection.

First seen as a prototype racer at the 1986 Bol d’Or, the first 851 ‘Tricolore’ was unveiled in 1987 and won the World Superbike championship in the hands of Raymond Roche in 1990.

Ducati 851

Its enlarged successor, the 888, won with Doug Polen in 1991 and 1992 before in turn being superseded by the further enlarged and fully redesigned 916 in 1994.

The success of the 916, and subsequent 996 and 998, requires no retelling here. But its dominance over the next eight years, including six WSB titles, marked a high point for the L-twin which, certainly with hindsight, no successor could have been expected to repeat.

Not that it stopped Ducati from trying. The last ‘916’, the 2002 998, saw the updated ‘Testastretta’ (meaning narrow head) engine which was actually first used in 2001’s limited edition, race-spec 996R.

The 998 was then itself replaced in 2003 by the controversial, Pierre Terblanche-styled 999 which, although widely disliked, went on to win three more WSB titles.

Then, in 2007, Ducati reverted to styling form with the 1098, powered by a further updated ‘Testastretta Evoluzione’ engine. The new lump was not only larger to take advantage of new WSB rules for twins, but featured an even narrower included valve angle and new manufacturing techniques which greatly improved reliability, yet still produced 160bhp.

The Final Edition

Ducati Panigale 1299 Final Edition

Even so, despite continuing success including Troy Bayliss’ 2008 WSB crown, followed by Carlos Checa’s repeat in 2011 aboard a further enlarged 1198 version, the writing was on the wall: Ducati’s L-twin no longer enjoyed the dominance it once had against a new breed of four-cylinder superbikes such as BMW’s new S1000RR.

There was, however, one final Ducati L-twin, superbike ‘hurrah’ – the all-new, Superquadro-powered Panigale.

Unveiled the year after Checa’s 2011 WSB victory, the Superquadro was the ultimate L-twin and, as we now know, also the last before Ducati’s switch to V4s.

Although still a desmo L-twin, the Superquadro was fundamentally different from the Testastretta in being an ultra short-stroke, ‘oversquare’ design to enable the high rpm necessary for extreme power.

Carlos Checa

In addition, for more precise, reliable valve timing, belt drive was replaced by gears and a chain.

Furthermore, while the 2012 original exploited WSB regulations to the full in being 1199cc, in 2015 road versions grew further still to 1285cc (the racers remained 1199cc) taking peak power up to 209bhp for the 2017 Panigale R Final Edition.

It was a fitting epitaph. Although the L-twin Panigale never achieved the WSB success of its predecessors (being the only Ducati superbike not to win WSB), it did win in BSB and, with the V4 now upon us, remains the ultimate incarnation of a signature configuration that stretches back five decades.

Over that time, no engine has been so closely identified with one manufacturer – or been anything like as successful.

With the desmo’s deletion from the Multistrada V4, too, it’s now the end of a remarkable era. Farewell Des, we’ll miss you!

Phil West

By Phil West

MCN Contributor and bike tester.