What is desmodromic valve actuation?

A desmodromic valve is a reciprocating engine poppet valve that is positively closed by a cam and leverage system, rather than by a more conventional spring. An engine using desmodromic valves has two cams and two actuators, each for positive opening and closing without a return spring.

What is desmodromic distribution?

Desmo is short for desmodromic, and it refers to the way that a poppet valve inside of an engine is controlled. In almost every four-stroke piston engine, the valves are opened via a camshaft and closed by spring pressure which comes from a valve spring. It’s a well-known system, it works, and it’s pretty simple.

What does Ducati DVT stand for?

Ducati have officially unveiled the “first motorcycle engine with variable timing of both the intake and exhaust camshafts.” The 1,198cc v-twin engine’s full name is Ducati Testastretta DVT, with DVT standing for Desmodromic Variable Timing.

Why does Ducati use desmodromic valves?

Ducati started using desmodromic valves in the 1950s because it let them rev their engines higher. When you rev engines higher and higher, you’re turning the crankshaft (and thus the camshafts) faster and faster. You’re asking the valves to open and then to close faster and faster, too.

How does a desmodromic engine work?

Desmodromic engines close valves with another cam. They use use two cams and two actuators, avoiding using a return spring. So one cam pushes the valve open, and another valve pushes it closed.

When did Ducati start using desmodromic valves?

1950s
Ducati started using desmodromic valves in the 1950s because it let them rev their engines higher.

What happens if you dont do desmo service?

The Desmodromic valves on Ducati’s are opened and closed by direct mechanical input, ( no valve springs ) ,failing to have them serviced can result in the valves striking the crown of the piston(s) having catastrophic and usually terminal results for the engine, also on some models the camshaft is driven by a belt …