1968 250 MK3D rebuild - ex W/C Oil Pump

[machten]

So I suspect that he didn't really get the chance to ponder all on his own that which he was presented with, before coming to any conclusion entirely of his very-own !
One clue to back-up that notion is the wording: "the highest he's seen to remove a bind" ... Cuz any good DESMO-mechanic will not have found himself in the situation of having to "remove" or deal with any kind of 'bind' ! - (Unless given such a created-problem by somebody-else.) _ As such issues no-doubt never came from the factory that way, (as far as I know) !

Well I have to disagree with that. (edit: that being "he didn't get the chance to ponder it") This guy had his own "bevel only" shop (he was the mechanic) for many years starting about 1980 and has rebuilt at least over 100 bevel engines (singles and twins). I left him alone to investigate whilst I was doing a fibreglass repair on his 73 Sport tank. He ain't gonna be snowed by my suggestions! He told me of binds he'd come across and was well aware of singles camshaft inaccuracies and clearance requirements. He mentioned examples including as late as bevel twin Imola cams. As an aside, this gentleman owned Bruno Spagiarri's 1972 Imola bike that came second to Paul Smart for over 10 years. He knows a bit about bevel engines, and more than enough to diagnose a desmo cam bind and I can assure you he'll tell me I'm talking rubbish if he thinks I am! (and that's putting it politely!)

Here he is riding Spaggiari's bike in the back blocks of Western Australia in the mid to late 70's. (yeah, it's a twin, but c'mon, it's still a bit interesting, and Spaggiari's greatest work was racing Ducati singles )

BRUNOs Imola Small.jpg

Anyway, life intervened today on doing the B&W camshaft check, so it probably won't happen until the weekend now. More on that soon, i hope.

Kev

[DewCatTea-Bob]

" What has now become a bit of an aside, but may be of interest to some people "

____ That post (concerning D.valve info) is very most certainly of well related interest and also of pertinent importance to anyone reworking any DESMO-head !! _ So that offered info is most welcome !
__ This sufficiently inspires me to disassemble my never before used 450R/T cyl.head, to measure my own new D.valves (ordered back in 1974), to measure them as well !
After I get those measurements, we should post a 'list' of all the varying dimensions !


" Both valves from Ian came packaged and sealed like so... "

____ That looks to be pretty-much exactly as new-valves would come wrapped from the factory back in the '60s & '70s, (only thing is that Berliner would then place such wrapped-valves into a part-number marked envelope as well, before boxed-shipment to dealers).
So unless someone wished to fool people who would recognize such factory wrapping, it's fairly certain that these valves are actual factory produced D.valves.


" So it seems there are a few different permutations of available valves, which is useful to know when you have limited spring retainer and collet collar sizes and shims!!! "

____ Indeed ! _ Now besides having a choice of thinner collet-shim and/or thinner spring-tie, you now may also have a choice of higher C-clip location,, all helpful for loosening-up the binding-issue which you've been faced with !
__ However, while I never before recalled ever noticing any such valve differences, I can say that new-valves with those variances never came into my possession that way... What I mean is that whenever we received an order of new-D.valves, they were always identical to each other ! - (Ya see, whenever we needed another D.valve for our-own stock-supply, we'd always order 2 of same, and I'd always look-over both at once, before choosing one for installation). _ So I guess I had always assumed that ALL were always the same as ever. _ If we had always kept-hold of examples of older stock whenever ordering new, time after time,, then I-MYSELF might have had an opportunity to have noticed such differences, and then certainly would've committed any such changes in design, to memory !
So even at this much later time, this new (to me) info, is quite impressing !


____ This last batch of posts on this related subject-matter, now most certainly begs to be all moved to it's very-own (new) thread !
So I hope to complete that worthy process, in due time. _ But before such attempt, it would be fairly helpful if everyone would appropriately re-title each of their so-related posts, so that they don't continue to state "W/C Oil pump" .
__ I think that since it's unlikely that many others will also have their D.rockers refaced much the same as Kev has had done, that therefore the new thread-title will rather have more to do with rocker-clearance setting with various DESMO-cams.


Fun-Cheers,
-Bob

[DewCatTea-Bob]

" Well I have to disagree with that. "

____ Not sure exactly what you mean by: "that".


" This guy had his own "bevel only" shop (he was the mechanic) for many years starting about 1980 and has rebuilt at least over 100 bevel engines (singles and twins). "

____ Well now I'm more properly impressed !
(However, I still don't think it's fair to unexpectedly present any average-type mechanic with a fairly complex issue of which they've been retired from for many years. - As it takes a fair amout of alone-time to get one's memory back into the old swing-of-things once well known of.)
__ If he has agreed that he didn't feel under any pressure to come-up with his best thoughts on the issue, then you pobably got near his best thinking on the topic.


" He told me of binds he'd come across and was well aware of singles camshaft inaccuracies and clearance requirements. "

____ One just shouldn't "come across" such binds (as we've been referring to), by simple chance ! _ Any D.cam/rocker-binds are (usually unmemorable) temporary mal-adjustments unintentionally created while resetting the rocker-clearances ! _ They otherwise shouldn't ever exist & earn any such term of their very-own ! _ So I really don't understand how it seems that a desmo-related "bind" has seemed to have become such a standard-issue to be much concerned with ! ...
____ If the whole process of desmo-clearance resetting is done properly, then no binding-issues are ever run-into to become left concerned with !
__ What ya should do after a valve-job or replacing one or more related D.parts, is install the closing-rocker with absolute minimum-shimming and then set the opening-clearance to spec... THEN shim-up the closing-clearance to near zero AT the POINT CLOSEST to the most intolerant binding-spot. _ Easy & simple, and without running into any binding-issues to become left CONCERNED with ! - (Such bind-ups only TEMPORARILY occur while rushing-through the clearance-setting work with limited shim-selections!) _ And any closing-slop left noticed at TDC is merely just that which it happens to be, and nothing at all to ever be concerned with (unless ya happen to be an uninformed desmo-perfectionist) !


" life intervened today on doing the B&W camshaft check, so it probably won't happen until the weekend now. "

____ That's okay, as such an interesting project as that is going to be well worth the wait !


Hopeful-Cheers,
-Bob

[wcorey]

Just measured my valves, two 36mm ex and one 40mm int.
Length/end to groove center, one ex is 84.7/4.7, the other is 85.4/5.4, the int is 86/4.4.

I set up my head last year to make sure everything went together ok and see if I needed anything, but had since disassembled it again. I don't recall any binding issue and I always put a feeler gauge in to take up any clearance and rotate everything 360. I guess I got a 'good one'...
I'll be reassembling soon so I'll get to check it all again keeping this thread in mind.

It occurred to me that if I put my 996 on the road this year, it's due for belts and doing valve clearances. Two heads times four valves each, like doing four singles. Doing a Desmosedici 16rr would be equivalent to eight of 'em...

As for Kev's references to what has been said about encountering 'cam bind', I just assume that means seeing the potential for bind if the clearances were not set at the high point, as opposed to actually finding such a condition pre existing in a head.




Bill

[DewCatTea-Bob]

" I don't recall any binding issue
I guess I got a 'good one'... "

____ Well either you got a "good one" (without any notable binding-spot), and/or, you had proceeded to set your desmo-clearances in proper-order (thus bypassing any run-ins with any possible binding-points).


" I'll be reassembling soon so I'll get to check it all again keeping this thread in mind. "

____ When you do, it would be more interesting if you would PURPOSELY try to run-into any possible binding-point which YOUR D.cam may have. - (After having read most all of this thread, it should then be fairly-clear how attempting to do so, could be more easily accomplished !)


" As for Kev's references to what has been said about encountering 'cam bind', I just assume that means seeing the potential for bind if the clearances were not set at the high point, as opposed to actually finding such a condition pre existing in a head. "

____ Well that seems to make it clear that more extensive terminology needs to be established & employed...
Since it has indeed been possible to find a D.head that's been run with a (rather slight) rocker-bind (unknowingly) left in place, (due to nonDESMO-mechanics setting their closing-clearances at TDC).
I think the term 'binding-area' should be used for such reference,
and I think the term 'bind-up' should be used intending reference to a locking-up point which (temporarily, during clearance-setting) actually totally stops any further rotation,
and I think the term 'bindable-cam' should refer to the less perfect examples of D.cams with more pronounced preexisting "potential" binding-conflict conditions which are quite capable of leading to run-ins with conflict-binding issues.
__ Of course those suggested terms are open to refinement, but unless some entity has already established such distinguishing terms for such diverse uses, then it's fairly-clear that we-ourselves ought to get a separate/distinguished term for each varied use (of "bind"), understood collectively by all .
(Otherwise we can all just continue-on clumsily misinterpreting exactly what each-other actually means.)


Hopeful-Cheers,
-Bob

[machten]

____ This last batch of posts on this related subject-matter, now most certainly begs to be all moved to it's very-own (new) thread !
So I hope to complete that worthy process, in due time. _ But before such attempt, it would be fairly helpful if everyone would appropriately re-title each of their so-related posts, so that they don't continue to state "W/C Oil pump" .

Bob - I've classified mine as best I can. I should have started a new thread at least once somewhere along the way, but one rat hole just led to another at the time.

Kev

[machten]

I went to the local vintage motorcycle club swap meet today, more out of interest than anticpation. There was one guy there selling a few ducati singles pieces, but nothing I was particularly chasing. Whilst there, however, I ran into a locally well known gent who I have come to know more recently as a fine and knowledagble fellow with a long pedigree in ducati singles who has been exiting the field over the last 6-12 months. I was telling him about my experiences covered in this thread and he declared that he had 2 unused VeeTwo cams at home and invited me around for a look and a coffee if I was was interested.

"Yes please!! (on both counts)"

The upshot is that I now have a brand new VeeTwo camshaft - they call it "Street - Race" camshaft - amongst some other little gems I was chasing. It is certainly radically different to the stock White/Blue. See below...

Note the different arrangement at the end opposite the bevel. The face doesn't sit up near the cam block bearing.

P1011406.JPG

The profile is noticably different. It will be interesting to see how this cam works for street use. One of the other bits I picked up from him is a conti style pipe, which will help things, i think. I already use a VHB 29 carb.

P1011408.JPG

Specs for this cam from my measurements - as best i can do with a digital vernier...(apologies for the formating, I've tried both tabs and spaces - same result)

Camshaft 4 - VeeTwo Road/Race
EC IO EO IC
Max 41.1 30.9 31.03 40.86
Min 29.82 19.13 19.94 28.77
Lift 11.28 11.77 11.09 12.09
Valve Closer - Opener Exhaust 0.19 Inlet 0.32

Another thing of note is that this VeeTwo camshaft is 1oz lighter than the stock W/B.

The specs came with it and appear below...

P1011413.JPG

Some fun to come testing this!

Kev

[DewCatTea-Bob]

" I now have a brand new VeeTwo camshaft - they call it "Street - Race" camshaft -
It is certainly radically different to the stock White/Blue. "

____ "Street - Race " , for which size engine ? _ Cuz that which is wild in a small cylinder becomes rather mild in a much larger cylinder !
I would expect good/desirable results from your new V2-d.cam with/in a 450 but, I would recommend against it's use with/in a (non all-out racer) 250. _ (Not in any attempt to talk you out of trying-it-out however, as we'd all very much like to know how it works-out for you !)
__ Now it will be interesting to see if another desmo.cam maker can make them any better than Ducati did, so hopefully you will take the extra time to PURPOSELY shim for checking for any possible conflict-binding, (just to see how it compares to any other Ducati-made D.cams you've checked).
__ That is, IF that wilder d.cam will fit into your (stock) D.head...
I've asked you about this possible fitment-issue before, as I've heard that SOME of the V2-d.cams will not fit into a stock-sized cam-tunnel !


" Note the different arrangement at the end opposite the bevel. The face doesn't sit up near the cam block bearing. "

____ It may be that they were thinking of compatibility with using a wider dual-row ball-bearing or roller-bearing type cam-bearing, installed within the bearing-support cap. _ Could be of some worthwhile use I suppose. _ (Hey Eldert, any thoughts on that?)


" The profile is noticably different. It will be interesting to see how this cam works for street use.
I already use a VHB 29 carb. "

____ It's no-doubt a good deal even wilder than the B&W D.cam, which ought make it fairly worthless (improvement-wise) over your stock 250's D.cam (for any 250).
I'd expect the power out-put under 4k-RPM to suffer (even more-so!),
mid-range ought remain roughly the same & unnoticeably-altered, and top-end could well improve but, the 29mm carb will choke-off what the extra-wild cam is capable of delivering at those high RPMs, (so a 32mm carb & matching in.port will be of more use, up-there!).
__ It's too bad that you don't have two DESMO-250s, so that you could then be able to confirm that my expectations are pretty-much the actual case !


" (apologies for the formating, I've tried both tabs and spaces - same result) "

____ From my experiences with most forums (where I'm allowed to use mostly CAPs), I've learned that they unfortunately ignore any more than one 'blank-space' in a row,
which is the very-reason why I've developed the habit of using these:' _ __ ____ ' !
So with those space-holding marks, I can fix-up your format spacing-issue thusly.....

Camshaft 4 - VeeTwo Road/Race

________ EC _____ IO _____ EO ____ IC
Max ___ 41.10 __ 30.90 __ 31.03 __ 40.86
Min ___ 29.82 __ 19.13 __ 19.94 __ 28.77
Lift ___ 11.28 __ 11.77 __ 11.09 __ 12.09

Cam-lobe Closer-minus-Opener difference... Exhaust = 0.19 ; Inlet = 0.32mm .
_______________________________________________________________________
__ I hope that My reworded lowest-line has correctly interpreted that which you had actually meant to indicate with your-own original lowest-line !


"Another thing of note is that this VeeTwo camshaft is 1oz lighter than the stock W/B. "

____ Could you tell us what percentage less that is, or just give us the actual weight of each ?


Excited-Cheers,
-Bob

[wcorey]

Nice find Kev!
With the increased lift combined with the decrease in duration from the B&W's (305/303 vs 332/325) my bet is that you'll see some gains through most of the power band. Downside is a bit more thrashing of your valve train and also that I believe you need to modify the head to install these (?). I'm wondering if the difference on the cam block bearing end is somehow due to such modifications.
I would agree with Bob that the carb and port size may restrict the gains it could achieve at the high rpm's the 250 is capable of.

While it's a step in the right direction toward what the newer 2v belt motors run, I'd still like to try one with something like 11.5/10.5 lift and 260/260 duration, though it could be that it's not done as the extra abruptness of actuation would stress the valve train past being reliable. The high lift, small overlap formulation is largely responsible for why modern Ducati's have such an incredible width of power band and where desmodromic's have a real advantage.


Bill

[DewCatTea-Bob]

" With the increased lift combined with the decrease in duration from the B&W's (305/303 vs 332/325) my bet is that you'll see some gains through most of the power band. "

____ Well that is certainly correct thinking ! ...
However, my expectations were based on the likely-hood that increased-lift most likely comes along with increased duration as well, (as I'm unfamiliar with the actual specs of Kev's new V2-d.cam!).
I'd like to know how you came-up with those stated duration-figures and how you know that they are fair to directly compare with Ducati's, (since many such stated-figures are not taken at the very-same lift-points as Ducati has done them !).
__ I was once told by a fellow-Duker that he had gotten from a well-respected source that the B&W-D.cam's "real" durations were only 310 for the intake & 300 for the exhaust ! _ Which at the time I assumed were probably taken at the (non-Ducati) standardized 1mm (valve & seat gap) point.
But later, I figured that somebody had gotten those duration-figures from some INCORRECT data posted at some other DUCATI-w.site, (as those particular figures actually match-up with the factory-specs given for the WideCase 250Mark-3 !).


" I'm wondering if the difference on the cam block bearing end is somehow due to such modifications. "

____ That's fairly doubtful, cuz modification of the cam-tunnel would have no concern or effect on the cam-bearing or the bearing-support cap itself.


Dukaddy-DUKEs,
-Bob