Published by on August 22, 2021
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Desmodromic valve drive was often justified by claims that springs could not close valves reliably. There was once a time when Desmodromic valve technology was cutting edge and a necessary competitive advantage for Ducati in racing. Ducatisti around the world know that the red bikes have desmo valves. Not all of them can tell you what that means, exactly. The Greek words.

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Think about how many valve spring breakdowns you have seen or even heard of in the modern era. Archived from the original on Desmo valves are a technical anachronism but still useful, desmodomic they haven’t been put out to pasture, edsmodromic of like your favorite WTATWTA author.

Mercedes Benz didn’t drop the idea of the desmodromic valve actuation because it performed better in ways that made the additional complexities worthwhile. This springless system remedied every problem created from spring cam mechanisms in high-rev engines.

One cam and actuator to open the valve and the other set to close the valve. Second, the valve does not completely return to its seat before combustion begins. At this point, it should be plain to see why desmo valves are still in the game: Deamodromic V4 and it marks a new and important chapter in Ducati’s history. Fabio Taglioni was an engineering giant able to blend masterful command of mechanical knowledge with tasteful, good-looking execution. This is great when a car is going fast, but engines with stiffer springs have to work harder at lower RPMs, resulting in worse fuel economy and greater wear on the engine and valvetrain.


The Mark 3 was the very first production Ducati to feature desmodromically actuated valves.

Desmodromic valve

Theoretically this rotary valve approach resolves many limitations of the poppet valve whilst also offering many other benefits. Cam and spring valves only really have to deal with the sliding friction of the valve stem into the cylinder. Why did Ducati use this type valge valve mechanism as opposed to a more tradition under the bucket shim design? The use of desmodromic valves is also why Ducatis are known for being incredibly fast motorcycles.

Less obvious secondary effects is that valve springs typically weigh as much as the valves which they actuate, that mean the total mass which needs to be moved by the actuation mechanisms belt, bearings, shafts also need to be larger in order to avoid fatigue failures. On December 11,the Grand Prix Commission announced that the MotoGP class would switch to the 1, cc motor limit starting in the season. Valve bounce is a related condition where the valve does not stay seated, due to the combined effects desomdromic the valve’s inertia desmodromci resonance effects of metallic valve springs that effectively reduce the closing force, and allow the valve to re-open partially.

Just inserted it to make it simple for people like me to look up what desmodromic valvetrain is. Stronger valve springs is one way to address this, but they have their own set of problems.

Ducati: Moto, MotoGP & Superbike

Post Your Answer Discard By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies. It’s only fair to share This can also overheat the valve, possibly warping it and leading to catastrophic failure. This allows cylinder gases and pressure to escape prematurely, which causes a major decrease in engine performance and can cause the valve to overheat, possibly causing warping or catastrophic valve failure or both.


The problem is that metal wire has inertia. Formula 1 engine manufacturers use a pneumatic system to close the valves to allow for very high RPM without valve float.

Service and Maintenance Services. Engineers designed the desmodromic system to remedy this very common problem. Share 0 Join the Discussion.

Desmodromic valve systems are first mentioned in patents in by Gustav Mees.

Engine metallurgy of old kind of sucked. The desmodromic valve actuation system that Ducati have some patents for is considerably different than the first desmodromic valve actuation systems that were invented and aforementioned. The new Hypermotard is the perfect choice both for moving in traffic and having fun outside the city.

To prevent leakage of gas between valve stem and guide, a highly effective seal is located there. The springs are only necessary to take up the closure system slack.

Relevant discussion may be found on Talk: Inthe Maserati brothers introduced one of their final designs: