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Desmodromic valve

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its off there MotoGP bike

they use it on pretty much all their street bikes, and have been for like decades.

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And the only reason they do it is because they are Italian! :thumbsup: Italian engineers march to the beat of a different drummer and do whatever they want. Taking other people's designs and existing products off the shelf is not a common practice in Italy (though they are learning to adapt that practice now with today's global ecomony).

That valve train is supposed to be pretty reliable though.

Chris.

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Yep-

Ducati has been using that technology for a looonng time now. They have pretty much mastered it - I think.

Mercedes fiddled with it in the 50's

The idea is pretty simple, but getting it to work in the real world is something else altogether. It took Ducati and others quite a while to get it to work properly for consumer use.

The tolerances and metallurgy requirements etc. are pretty stringent for this design.

BJ

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The maintenance interval for engines with desmodronic valves are quite short. If you own a Ducati, hopefully you know a competant mechanic very well or have major bank stashed away to keep the bike in perfect tune. They are beauitiful, soulful machines that can go like stink. They just require alot of tuning.

Ducati has used this system for quite some time now. I would not venture to say that it is the most reliable valve train design out there on the market. The Daytona 200 is arguably the most demanding road race in the world on equipment. Ducati's are notorious for breaking down at middle to 3/4 race distance for the past 20 years or so.

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That valve train is supposed to be pretty reliable though.

a couple of my buddies ride Ducati Monsters and they have had no problems with the valve train...but they have to check there valves about every oil change and they are always adjusting them every other oil change. So they seem to be pretty labor extensive...more so than my CRF...but then again i change my oil every ride and don't know how many miles I have on my CRF

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the surprising thing is ducati will still use the Desmo valve in their 800cc motogp bike next year and it reportedly revs out to 18,000rpm! the other companies are moving to pneumatic valves. ill try to find the article where the ducati engineer explains the desmo valves advantages over stiffer and stiffer valve springs.

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The maintenance interval for engines with desmodronic valves are quite short. If you own a Ducati, hopefully you know a competant mechanic very well or have major bank stashed away to keep the bike in perfect tune. They are beauitiful, soulful machines that can go like stink. They just require alot of tuning.

Ducati has used this system for quite some time now. I would not venture to say that it is the most reliable valve train design out there on the market. The Daytona 200 is arguably the most demanding road race in the world on equipment. Ducati's are notorious for breaking down at middle to 3/4 race distance for the past 20 years or so.

All of their engine failures during Daytona were cam belts. Ducati insists on using cam belts instead of chains or gears like japanese companies.Desmo valves need more adjustments and maintenance but can do the 200. I have a friend that worked a few years ago with Fast By Ferracci Ducati. He always said if they could have ditched the damned cam belts for chains it would have been a much different outcome. Got to give them credit though , the ducs still did more laps than the harley VR 1000 or any buell ever will. :applause:

P.S. Weird to talk roadracing overhere. I'm new to the dirt, just retired from roadracing. :thumbsup:

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All of their engine failures during Daytona were cam belts. Ducati insists on using cam belts instead of chains or gears like japanese companies.Desmo valves need more adjustments and maintenance but can do the 200. I have a friend that worked a few years ago with Fast By Ferracci Ducati. He always said if they could have ditched the damned cam belts for chains it would have been a much different outcome. Got to give them credit though , the ducs still did more laps than the harley VR 1000 or any buell ever will. :applause:

P.S. Weird to talk roadracing overhere. I'm new to the dirt, just retired from roadracing. :thumbsup:

ducati should just be immensely thankful that Aprilia doesnt race the daytona 200......a thousand times better looking than the fugly 999 series....incredible v twin sound .....nowhere near as maintenance intensive as the desmodromic valves.....and.......THOUSANDS cheaper......oh man do i love my RSV......

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Do you guys see any manufacturers ditching the old valve and spring technology? Also will Big bang engines ever make it to dirt?

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Also will Big bang engines ever make it to dirt?

Hehehe, for that to happen, we'd need more than one cylinder! Besides, we have the ultimate "big bang" engines right now! Big bang engines try to copy the power delivery of thumpers and V-twins.

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what is a big bang engine?? never heard that before

why not a rotary engine

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i was wondering why ducati used belt driven cams when i saw a cross section of their motors. i figured maybe its better, but now that i know its worse i think its pretty dumb.

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Ducati came up with the Desmo valves back when metalurgy and valve spring technology was no where near what it is today. At the time, it was a clear technological advantage. Today it's little more than a tradition, an opportunity to be different.

The Ducks do not rev out any further due to valvetrain design than a properly designed spring system. If anything, it's a disadvantage. Compared to a conventional valvetrain, a Desmo one has: more moving parts, increased heat/friction from those parts, higher weight, more weight placed up high on a motor, increased difficulty and time needed for checking/adjusting valves, and greater cost.

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I beleive some of the F1 teams use pneumatic valve system and they rev them to about 19K.

Aprilia used pneumatic valve system, I believe, in their failed attempt at MotoGP. Hella powerful, and high rev'ing. But not useable power.

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