Ducati Desmodromic Valves: Wasn’t Born To Follow

The following is a re-edit of a piece posted by MotorMartin on DriveTribe under the I Love Motorbikes banner run by Tony Yates, perhaps better known as @Xinterceptor.

Dedicated to Nicky Hayden 1981-2017 

There are certain manufacturers worldwide that the non-motorcycling members of the general public are aware of due to how the brands have cleverly made themselves more visible than most. Triumph springs to mind as does the might that is Honda, but there’s another. A firm that used to be a byword for financial oblivion but is now a much sought after firm, so much so that only a few years ago Audi rocked up to a bright red, noisy party with a wallet full of cash and promises of world domination.  

So what first attracted one of the Volkswagen groups’ favourite children to bid and buy a classic Italian motorcycle firm? A firm which, and let’s be honest here, is never going to rival the big four Japanese manufacturers when it comes to production volume or amount of sales.  

The answer has got to be the engine and its history. Ducati have always experimented with different engine configurations over the years but are perhaps better known for their twin cylinder V-twin (L-twin) engine, both air and water cooled over and above all of the others. The thing is though, is that Ducati have something that nobody else does. 

The Ducati bevel-gear twin-cylinder with a 90° V configuration (the L-twin) was created at the back end of 1970 when, everybody’s favourite Ducati engineer, Fabio Taglioni drew the design that would send the firm along their first steps away from the single-cylinder Desmodromic engine that had historically provided their heartbeat to the L-twin Desmodromic configuration leading on to a sporting legacy that continues apace even today. 

And it’s that Desmodromic system that is perhaps the most impressive and different aspect of the engine, both single and twin, an aspect that makes Ducati unique upon the world stage. Indeed, In 1956, Fabio Taglioni, a Ducati engineer, developed a Desmodromic valve system for the Ducati 125 Grand Prix, creating the Ducati 125 Desmo, saying at the time: The specific purpose of the Desmodromic system is to force the valves to comply with the timing diagram as consistently as possible. In this way, any lost energy is negligible, the performance curves are more uniform and dependability is better.  

In short then, as in a valve-spring engine, a cam lobe operates a pivoted finger follower that presses against the end of the valve stem to open the valve. A second, complementary cam lobe on the same camshaft operates an L-shaped closing lever whose clevis-shaped other end pulls the valve closed, acting against the underside of a collar fixed to the valve stem. 

Therefore Desmo eliminates the usual problems with springs, while the absence of conventional spring load saves some frictional loss at low to mid-rpm. In short, the benefit of Desmodromic valves lies in the ability of the engine to allow higher valve acceleration and deceleration without the risks of a collision between valves and pistons occuring. 

Ultimately though, Ducati still uses Desmodromic valve technology because that’s kind of what they’ve always done and now it’s become part of their tradition. Ask anyone about Ducati and after Carl Fogarty, they’ll mention the Desmo system (Probably).  

With Ducati forging their enviable reputation through their racing exploits it’s inevitable that the Desmodromic technology, for which they are so well known, is continually improved through the highly stressful racing environments of Moto GP, World Superbikes and the various Superbike Championships taking place around the World. The link between Ducati’s traditional valve technology and their race machines is made abundantly clear when you notice the name given to the 2017 MotoGP racer, the Desmosedici, a Liquid-cooled, 90° V4, four-stroke, evo desmodromic DOHC, four valves per cylinder beast putting out a guesstimate of around 250+bhp, so the technology does work quite well enough.  

Even the lesser (sic) World Superbike Racer, Ducati Panigale R Superbike, has a liquid-cooled, 90° V2, four-stroke, desmodromic DOHC, four valves per cylinder putting out around 215+bhp. The Desmodromic system may have been started with the intention of solving an engineering dilemma in a new and innovative way, but then it became something more.  

Ducati’s traditional engineering solution to the ever increasing revs and valve spring technology limits that progress brings about is such a big part of what Ducati means today. Without the Desmodromic technology Ducati would perhaps be just another manufacturer but today, to the designers, engineers, racers and customers, Ducati means so much more than it’s motorcycle range. It is a truly legendary company. 

Where will you go?

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