Ducati: Desmo Valves History
In 1954, Ducati was a manufacturer of small displacement, somewhat docile motorcycles intended as simple, affordable transportation for a weary country recovering from a devastating war.
The company’s then general manager, Giuseppe Montano, was taking a serious look at how participating in motorcycle racing competition could potentially boost sales.
Montano sought out Fabio Taglioni, a young, talented engineer, and said, “I know your talent and I need you. If you build 100 motorcycles to win the Tour of Italy, Ducati will stay open, because I only have one month’s salary for my workers. If not, we shut down and everyone goes home.”
Rather inauspicious beginnings for what would ultimately lead to the use of the now famous Desmodromic valve system. Although Ducati is attributed with the invention of the Desmodromic valve system, Mercedes-Benz was the first to use the system on its W196 Gran Prix and 300SLR sports cars in 1954 and 1955.
Taglioni was ripe for the challenge and set to experimenting, figuring out innovative paths to coaxing maximum power out of the small Italian engines. He knew that metallurgy of the time limited the resonance of valve springs to operate at high rpm, the reciprocating parts of a combustion engine literally outrunning the valve springs ability to return valves to the closed (or seated) position before the piston came up to top-dead-center, resulting in “floating,” (the piston coming into contact with the valves).
Also, valve springs, due the limited metal compounds of the day, were especially susceptible to fatigue and contributed to their share of engine failures.
Taglioni reasoned that a valve that was forced closed by the cam could avoid the inherent problems and limitations of springs and therefore higher rpms could be achieved.
Taglioni and his team started building these cam-driven exhaust valve motors, naming them Desmodromic, which translates to “controlled movement.” In early experiments they discovered that in addition to higher achievable rpm, there was an increased efficiency of disbursing burnt gases, as well as producing higher torque at lower engine revs.
Refined over the years, the Desmodromic system remains a relevant technology despite advancements in metallurgy that allow for the manufacture of high rpm valve springs-as evidenced by the system still powering the mighty Ducati MotoGP machines.
Moreover, the Desmodromic system provides a highly efficient intake/exhaust flow, limiting the blow-by of unused fuel to be emitted into the atmosphere, in effect making the system-originally designed purely for performance purposes-into a somewhat environment-friendly motor.
The Desmodromic system remains a proven design and the exclusive signature of Ducati, helping add its unique bit of audible charisma to the iconic brand.