| View previous topic :: View next topic |
| Author |
Message |
cat
Joined: 30 Nov 2005
Posts: 398
Location: South Africa
|
 Posted: Wed Apr 26, 2006 4:32 pm Post subject: |
 |
|
| Fil wrote: | | I think the Ducati V-twins use cam belts running on the outside of the engine - kind of like a car. |
I thought they were gear-driven - the desmos, but I don't really know - I'm quite ignorant about them, but my friend has two in his shop. I just know that the desmodromic system closes the valves mechanically instead of by valve springs. But even that, I could be wrong. Apparently they're difficult or fiddly to adjust the valves. |
|
| Back to top |
|
 |
Fil
Joined: 22 Jul 2005
Posts: 144
Location: Shropshire, England
|
| Posted: Wed Apr 26, 2006 5:48 pm Post subject: |
|
|
I'm pretty sure all the 'modern' Ducati V-twin use cam belts to drive the cams which operate the desmodromic valves. You can see the cam belt covers on the right hand side of the engine.
I think that some of the earlier Ducatis used a bevel gear system to drive the cams. This consisted of a bevel gear on the crank turning a shaft for each cylinder, which ran up the side of the barrel to another bevel gear which drove the camshaft.
They've used the desmo valve system in most of their engines for many years now, which as you say, closes as well as opens the valves, rather than relying on springs to close them like most engines do.
Don't know why no one else uses it - seems like a good (if a little fiddly to maintain) system. |
|
| Back to top |
|
|
cat
Joined: 30 Nov 2005
Posts: 398
Location: South Africa
|
| Posted: Wed Apr 26, 2006 5:51 pm Post subject: |
|
|
| Fil wrote: | I'm pretty sure all the 'modern' Ducati V-twin use cam belts to drive the cams which operate the desmodromic valves. You can see the cam belt covers on the right hand side of the engine.
I think that some of the earlier Ducatis used a bevel gear system to drive the cams. This consisted of a bevel gear on the crank turning a shaft for each cylinder, which ran up the side of the barrel to another bevel gear which drove the camshaft.
They've used the desmo valve system in most of their engines for many years now, which as you say, closes as well as opens the valves, rather than relying on springs to close them like most engines do.
Don't know why no one else uses it - seems like a good (if a little fiddly to maintain) system. |
Yes, I was confusing bevel with desmo - I've done it before.  |
|
| Back to top |
|
|
|
