[nottonight68]

talking to some young belt riders the other night--couldnt convince them my 76 ss was a 4 valver-no matter how hard i tried

 

[sfyamr1]

I'm pretty sure there's no way in hell any bevel was ever a 4-valve. The first 4-valve Duc I think, was the 851 in '90.

But, as a not-so-young belter who loves a mechanical challenge, I'ma look tha shit up

 

[sfyamr1]

Indeed, as you can see sir, from the engine diagram for '75-'76 SS, the motor is a "Desmodue", and not a "Desmoquatro" as you thought.

http://www.ducatimeccanica.com/900ss_spareparts/
Diagram:
http://www.ducatimeccanica.com/900ss_spareparts/22.html

You owe those whipper-snappers a beer.

 

[nottonight68]

but everytime ive worked on my heads,ive had to repair/grind/lap/and set 4 valves--2x exhaust and 2x inlet--a 4 valver for sure--came that way from the factory

 

[Passinglane]

I could see that coming a mile away!

Bruce

 

[st2lemans]

Well, the D16 has 16 valves total, not per cylinder, do in that respect it is correct to view a bevel twin as a 4V.

Cars are also normally viewed that way.

Tom

 

[DesmoDog]

Somewhere I have a picture of a four valve head for a bevel single... but it's not factory built so I suppose it doesn't count.

It's been done, it's just not cheap. Or even what I'd call affordable. In fact I'd go so far to say it's flippin expensive - I never got a firm price but from what I gathered I'd have at least $10k (US) into it before I was done.

Yeah... I've been known to overspend on Ducs before but that was a little over the top for me...

 

[wdietz186]

Back in 1975 I told a dirty shirt wannabe my 750GT was a prototype Sportster and I was a factory test rider doing durability testing. Yep! 90hp and it will do 150mph. The name on the tank? Just some letters they had lying around.It was all great fun.

 

[ducatidave]

I read where the factory experimented with 4 valve heads for the bevels (both racing & road bikes) but found no advantage over the 2 valve layout.

 

[Macdesmo]

I saw an article some years ago where an engineering student in the US built 6 valve heads for a bevel as a project and the results were very good. I can't remember which mag or which year.

 

[851Tricolour]

I'm pretty sure there's no way in hell any bevel was ever a 4-valve. The first 4-valve Duc I think, was the 851 in '90.

But, as a not-so-young belter who loves a mechanical challenge, I'ma look tha shit up

My 851 TC is 1988.

 

[RedST]

I saw an article some years ago where an engineering student in the US built 6 valve heads for a bevel as a project and the results were very good. I can't remember which mag or which year.

Not a bevel (or desmo for that matter), but Francesco Romanelli built 6-valve heads for belt-drive ducs.

http://www.romoto.com/engines.html

http://www.romoto.com/tema.html

His stuff is pretty far out there. Peripheral plasma discharge ignition...engine cooling via heat-conductive graphite foam...W-9 configurations with gas direct injection...4-valve HD evo motors....torsion-bar rear suspension.

Fascinating stuff.

 

[Sal996R]

but everytime ive worked on my heads,ive had to repair/grind/lap/and set 4 valves--2x exhaust and 2x inlet--a 4 valver for sure--came that way from the factory

there are no air cooled bevel with 4 valves per head for serial production engines.

 

[willness33]

there are no air cooled bevel with 4 valves per head for serial production engines.

Go back and re-read the thread. You'll get the joke.

 

[Macdesmo]

SE84,
Thanks for the interesting info. I would have eventually have had to go and look for that and it would have taken me quite a while.
Ian

 

[Mad_Duk_Man]

I have some pics I could scan I took in Daytona years ago of a TT2 style bike with Honda XT600 heads on it (4 Valve)
Cycle magazine did an article on it in the late 80's early 90's........

How Odd anyone would chose to call their bevel Ducati a 4valve......

Does that mean an 851 is an 8-valve? Odd how how no one ELSE in the world refers to Bevel twins as 4 valve except you..........

Maybe we should call your bike "Shaft-Drive" too

I mean, it IS shaft drive, right? (just not the real wheel like EVERY one else in the world)

I guess if you wanted to be a goofball you could argue it's not an Italian bike, but a Roman bike..... ect.....

 

[st2lemans]

How Odd anyone would chose to call their bevel Ducati a 4valve......

Does that mean an 851 is an 8-valve?

Yes.

You don't think that a Desmo16 has 16 valves per cylinder, do you?

Tom