22 replies to this topic

[Marco94]

Hi there,

I have promised you to post a picture I made at the Galaria Ferrari in Maranello in 1997. It shows a cilinder head for a 1991 3.5 l F1 engine. But, it used desmodromic valve actuation! I have no idea what became of this project, as I was so smart to forget to write down the caption seen in the left corner. :-( Hope you enjoy it.

Marco.

[desmo]

Anyone else unable to see that image? I REALLY wanted to see this picture, but it won't finish downloading! Marco, either that is an awfully large file, or your server is on the blink. Marco, if the file size of the image reasonable (say <150K,) e-mail it to me and I'll upload it to my member space and repost it here for all to see.

[Ursus]

I see it just fine. The URL is http://www.marco94.f...ri_f1_desmo.gif if you can get it that way.

[Top Fuel F1]

Thanks for the Pic. See it just fine.

Rgds;

[marion5drsn]

I can't get it either M. L. Anderson

[desmo]

Well after four tries, it still wont download for me. What on earth is the file size of that thing? If the file size is even close to being reasonable (let's say <500K this time) will one of you who can download it please PM or e-mail the image to me so I can at least see it? The top quarter or so of the image appears in a pixelated form and then it just quits downloading. I've never had this problem before.

[marion5drsn]

Desmo; Same thing here in Bellflower California! And being a desmodromic nut I would like to see it. M.L. Anderson

[Wolf]

I had no problem with D/Ling the pic, which is of reasonable size at that (128k, or thereabouts). I U/Led it to my site and will post it. If Marco or Desmo have anything against me doing so, please notify me and I'll remove it ASAP.

[desmo]

Wolf, Thanks for reposting the pic. Danut was kind enough to send me a copy of the image in bitmap format so I have seen it now, but my browser still only wants to display your reposted version. I have no idea why your version of the pic downloads for me and Marco's doesn't, but since I can see it now I'll ignore the problem as long as it doesn't happen anymore!

Is this head only desmo on the intake side? Look at the difference in the cams.

[Marco94]

I can see two of these images. The image is an interlaced, GIF89a of about 130 kB. That may very well be the problem from what you say desmo. I have just tried IE 5.5 without problem and Opera 5.0 also shows it without problems. All on WinNT 4.0. I have no other platform to check it on.

If you all could give me a round up of the browser you are using, I may be able to work out what is going on.

I have never had problems with F2S, that's the reason I use them. Not with my "site" or any other. I am using the LAN from my university, so speed here is plenty. Anyway, it is now 20 December 8:50 UTC as I write this. Do these problems persist or is everybody able to see it now. It could be that the server was being serviced.

Let me know, it bugs me too. Altough I can see it. ;-)

Marco.

[desmo]

Marco, I was attempting to view the image on IE5, so out of curiosity I tried it on NS 4.5 and same result, the image won't finish downloading although Wolf's reposted version downloads fine on either browser. I'm not even going to try to understand why, at least as long as it never happens again! ;-)

[Marco94]

I assume everybody can see the image one way or another. For the life of me I can't think of a reason for these problems to happen. You might want to try some other images on my home page, and see if they load OK.

Both valve have a desmodromic actuation, desmo.

Marco.

[marion5drsn]

I still can't download the first one but the second one downloads quickly. M.L. Anderson

[Alvega]

Desmo, can you give us more info about this engine ? I suspect Ferrari never actually raced a desmodromic V12.

[desmo]

Here's a much better look at it.

[AyePirate]

way way ot:

Desmo,

Who the hell is "Hambone Wilson"?
All I could come up with is
there is a bass player by that name
in (blues slide guitarist) Dave Hole's
band.

AP

[desmo]

Just a local muscian here who is a better guitar player than anyone you'll ever hear on MTV or in any contemporary pop music. Which ain't saying a lot, admittedly! Posturing and image are all that matter in current pop music. That's why N'Sync, Limp Bizkit, and Rap can dominate.

[marion5drsn]

It looks as tho the exhaust is the only one with the full desmodromic actuation as the intakes don't seem to have enough mechanism. Am I seeing this correctly? M.L. Anderson

[desmo]

Look at the radical difference between the exhaust-nearest-and the intake cams. So far no one has provided any theory why the two cams would be so different. Why does the intake can have so many more lobes than the exhaust cam. I don't know, but I am thinking about it.

The exhaust cam seems straightforward enough with the opening lobes conventionally placed and the closing lobes outboard of them adjacent to the cam bearings, but the intake cams are another story, it almost looks like they have three closing and three opening lobes per cylinder! Was this a five-valve head? I'm going to have to ponder this some more.

[marion5drsn]

Desmo; You're seen what I think also, but maybe I'm wrong. Possibly the picture is still too unclear. I hadn't thought about a five valve head. M. L. Anderson
Have you or I reversed the intake from the exhaust cam? (addition)[p][Edited by marion5drsn on 12-21-2000]

[desmo]

Having thought about it while I took the dog for a walk, it is now apparent to me that this is a five valve head with three intakes and two exhausts. Five valve desmo head, very slick!

The website I got the close-up photo of the head from will appeal to some gear heads out there. It's called Desdromology and is the site for a desmo museum in Holland! Here's the link:

http://members1.chello.nl/~wgj.jansen/

[Speedy4500]

That is a nice page, desmo. I never knew so many engines with such different systems existed. You might also be interested in the Spherical Rotary Valve System. It makes the poppet valve system seem antique. It has infinite lift, no springs, and is much simpler than desmo or almost any other current type of valve actuation.
http://www.coatesengine.com

[marion5drsn]

12-22-2000 The more I check this system out the more I believe that Ferrari tried to run before they could walk. If they had used a four valve system and developed it first it might of worked. Even if they had of used a two valve system that also might of been better yet. The people who designed this never heard of the rule of simplicity. From the simple to the complex is the way to go on something like this.
M.L. Anderson

12-23-2000 After looking at this some more I am wondering if this thing was ever run on a dynomometer? The top camshaft is very very peculiar, What is the extra lobe doing? Is it a balance counterweight? It may be that the picture is just not clear enough to make a correct evaluation! There seems to be four lobes on the bottom cam, but where are the arms to actuate the valve? Two of these lobes are right up against the bearing support?
M.L. Anderson[p][Edited by marion5drsn on 12-23-2000]