Topic: Ducati Mark 3D 450

[jas67]

This is my next restoration project.   It is a 1970 Ducati Mark 3D (D=Desmo) 450cc.

I've had this bike for about 10 months, and just now got around to getting it running and taking it for a ride.   It is quite light weight and fun to ride.  I have a 250 Monza, so, already knew what to expect handling wise (excellent), and brake wise (single leading shoe drum, 1950's technology, barely adequate).    The 250 is kinda slow, fine for tooling around on back roads at 50 MPH.  It'll do 70, but, not much more.  The 450 Desmo is much quicker.   It doesn't currently have a speedometer, so, I don't know how fast I was going, but, it gets up and goes, MUCH faster than the 250 as one would expect.






Here is what it will look like when finished.

[ekpent]

 Where did you find that at ?

[jas67]

Where did you find that at ?

Craigslist.

[Alan F.]

Did the PO know what they had?
Good score on a beautiful machine.

[Stev-o]

Great find, jas.  I would love to have a vintage Duc.

What is Desmo?

[MauiK3]

Desmo refers to the vertical shaft which engages the cam and valve gear and the valves are directly linked to the rockers, no springs as I recall. I could be wrong but I seem to remember it that way.

[jas67]

Desmo refers to the vertical shaft which engages the cam and valve gear and the valves are directly linked to the rockers, no springs as I recall. I could be wrong but I seem to remember it that way.

The vertical shaft drives the cam on both the Desmo and the spring valve motors.
Desmo means that there is a separate cam lobe and follower/rocker that actively closes the valve, not relying on the spring to do it alone.   This allows for much lighter valve springs, and much higher RPMs and/or more aggressive cam profiles.

See these videos:

https://www.youtube.com/watch?v=jgOg55g-Hs8
https://www.youtube.com/watch?v=ocfIYUc5bpU