Camshaft Identification

[DewCatTea-Bob]

[quote= Ian B ...
" Just re-measured quickly and get 32.45 not 33.00 "

____ That changes your "Cam2" in.lobe-height downward to 7.65mm, which is consistent with a 'Violet' Monza/Sebring camshaft,, so if it's in.lobe isn't worn at-all, (and you got the measurement correct this-time), then it has-to be a n-c.250-Monza cam.model (that's also employed in Sebrings),
(although the ex.lobe ought-to be about .1mm shorter).
__ When measuring USED cams, always get your reading from the unworn edge of the lobe (rather than taken near the center-area of the cam-lobe's used lift-track, [as more commonly done by newbies] ).


Dukaddy-DUKEs,
DCT-Bob

[Ian B]

[quote="DewCatTea-Bob"][quote= Ian B ...


____ Here in the USA, such used-cyl.heads have usually sold for under $150.
I have such spares, (but not much interested in shipping outside the U.S.).


Having had a really good look at the head this morning I've now realised that the inlet has been bored out and then sleeved. What I initially thought was a crack is in fact where the sleeve has been blended into the inlet tract.. Had mine been scrap I would now be BEGGING you Bob!

Cheers

Ian

[DewCatTea-Bob]

[quote= Ian B ...
" the inlet has been bored out and then sleeved. "

____ What seems to be the intended purpose of the sleeve ?
What's the new/resulted bore-diameter of the intake-port ?

Hopeful-Cheers,
-Bob

[Ian B]

[quote="DewCatTea-Bob"][quote= Ian B ...
" the inlet has been bored out and then sleeved. "

____ What seems to be the intended purpose of the sleeve ?
What's the new/resulted bore-diameter of the intake-port ?

I'm guessing that when the head was modified for racing they broke through the roof of the inlet port? The inlet diameter is 29mm. Other mods include 40/36mm valves, coil springs and twin spark plugs.

Cheers

Ian

[double diamond]

My records pretty much agree: #1 white (SCR), #2 intake measurement is SCR, exhaust is Monza, #3 monza/late GT/sebring, #4 green/white, #5 white. The #2 cam is the only one that doesn’t match any documented measurement. The intake lobe is consistent with a SCR (white) cam, the exhaust is close to monza/late GT/sebring measurements. Either the exhaust lobe has a lot of wear or the GB market got a cam that was different than US market. Could be something like a kit cam for the early Diana or a Daytona cam, neither of which I’ve seen dimensions of a positively identified example. Do the dimensions of the five cams appear identical (other than the lobes) from end to end (i.e left to right)? These dimensions may offer another clue.
Pretty common to break through the roof of the intake port with the combination of coil spring conversion and raising/enlarging the intake port. So the sleeve in the intake was likely a fix for this.

[DewCatTea-Bob]

[quote= double diamond ...
" #2 intake measurement is SCR, exhaust is Monza, #3 monza/late GT/sebring,
The #2 cam is the only one that doesn’t match any documented measurement. The intake lobe is consistent with a SCR (white) cam, the exhaust is close to monza/late GT/sebring measurements. "

____ I believe the three of us need to reach a non-contradictory consensus on the actual specs concerning cams #2 & #3...
__ My figuring from Ian's stated info comes-up with lobe-lifts of 7.65mm -(intake) & 7.58mm -(exhaust) for cam-2, which pretty-much matches the lobe-height figures of the original 'Diana-250-Monza' cam.model (which has an in.lobe-height between 7.55 & 7.65mm, and an ex.lobe-height between 7.4 & 7.6mm).
So this data indicates that cam-2 is a 'Violet' camshaft.
__ For Ian's #3-cam, my figuring comes-up with lobe-height figures of 7.78mm -(intake) & 7.65mm -(exhaust), which pretty-much matches the lobe-height figures of the 'Motocross' cam.model -(as stock for all n-c.Scrambler-models), of which features an in.lobe-height of 7.8mm and an ex.lobe-height of 7.6mm (+/- .05mm).
So this data indicates that cam-3 should be the original 'White' camshaft. - (Whereas Ian's cam-1 is the White-B, and his cam-5 is the White-C.)



" the GB market got a cam that was different than US market. Could be something like a kit cam for the early Diana or a Daytona cam, neither of which I’ve seen dimensions of a positively identified example. "

____ I don't know of any other unique cam.models specifically made use within the 'Daytona' model, but I believe that the race-kit camshaft intended for the 'Diana-250' was same as the 'Red'/Mk-III cam.model.


Dukaddy-DUKEs,
-Bob

[double diamond]

I caught the correction for cam #1 in Ian’s post at the bottom of page 1, but overlooked the correction to cam #2 measurements. So, yes, we are in agreement that cam#2 is an early Diana/Monza/GT/Sebring.

I have one documented example of a 4-speed Motocross cam that measured close to Ian’s #3 cam. Also have some Monza/GT cams that are close. If we consider the context of Ian’s sample, i.e. parts that were taken from GB market motorcycles, I think motocross model cam is unlikely, since, as far as I know, the motocross model wasn’t sold in the GB market. Ian doesn’t indicate that any of the chassis he has are Motocross/Scrambler models. The other white cams that have been identified are the later Scrambler spec, with intake lift ~8.2mm and exhaust lift ~8.0mm (although cam #1 doesn’t quite measure up). So, based on the data I’ve accumulated, I’m not convinced that the #3 cam is a motocross cam. Not saying it isn’t, but since I have no knowledge to speak of on the particulars of the GB market, there is still some question in my mind.

As far as speculating on GB market cam specs for the early Diana (and I am speculating, which is not entirely clear in Bob’s out-of-context editing of my original statement), I have no reliable figures on the GB market Daytona cam. It’s likely that the Daytona was the same specification as the US market Diana but I cannot state this with absolute certainty. As far as the race kit cam for the first production Diana, this is steeped in mystery. The kit cam may well have been a red cam as standard in the Diana Mk III, but, again, I have no verifiable record of a cam that was positively identified as provided in the kit and reliably measured. There are several mentions in contemporary road tests of a kit cam (and other hop-up parts available from the factory) but never any actual specifications. Since there were so few of these early Dianas imported into the US, and fewer still that can be positively identified as such at this point, let alone one that had a verified kit cam installed (and not a later installation of some other cam) the specification of the Diana kit cam may forever remain the subject of speculation. DD

[DewCatTea-Bob]

[quote= double diamond ...
" I have one documented example of a 4-speed Motocross cam that measured close to Ian’s #3 cam.
If we consider the context of Ian’s sample, i.e. parts that were taken from GB market motorcycles, I think motocross model cam is unlikely, since, as far as I know, the motocross model wasn’t sold in the GB market. Ian doesn’t indicate that any of the chassis he has are Motocross/Scrambler models. "

____ I don't recall of where Ian may've mentioned getting his 'cam-3' from,, however with it's specific identifier-details possessing near '7.8mm' (unworn) in.lobe-height and it's n-c.type large base-circle, there's then NO-other cam.model that it could possibly be, other than the 'Motocross-cam' (which was factory-original/stock for all Motocross/Scrambler n-c.models till 1967) !



" So, based on the data I’ve accumulated, I’m not convinced that the #3 cam is a motocross cam. Not saying it isn’t, but since I have no knowledge to speak of on the particulars of the GB market, there is still some question in my mind. "

____ Somewhat conversely,, I-myself am fairly quite certain that Ian's 'cam-3' is indeed the 'Motocross-cam.model'. _ Cuz according-to all my accumulated data, Ducati never produced any other (std.production) cam.model which duplicated those same two specific main identifier-details (I've mentioned above).
In any case at-least, certainly his #3-cam obviously falls-under the 'White' color-code category (along-with the same White-cam part-number) !



" The other white cams that have been identified are the later Scrambler spec, "

____ Have you been aware that there's been (at-least) THREE different "Scrambler spec" w-c White-cam.models ? ...
The 1967 w-c.250-Scrambler 'White-A' model; the 1968 250-Scrambler 'White-B' model (which was also factory-installed into [at-least USA] 450-Scramblers); and-also the (factory-intended/real)- 450-Scrambler cam.model.



" with intake lift ~8.2mm and exhaust lift ~8.0mm "

____ I-myself have never happened to have found any camshaft measuring with those particular lobe-height figures, but I certainly accept them (as being that of the '450-Scrambler cam.model' or the 'White-C' version, [also reportedly having been employed within some non-USA 350-Scrambler models]).



" (although cam #1 doesn’t quite measure up). "

____ Ian's 'cam-1' with it's near 8.0 & 7.8mm lobe-height figures, is rather quite common ! ...
I've personally measured at-least half a dozen (good unworn cams) with those very-same lift-figures ! _ And they all came out of stock (USA.type) 1968-70 250 & 450 Scrambler-models.
__ And since this particular White-cam version was the third 'White-cam.model' produced, that thusly makes it the 'White-B' version.




" (and I am speculating, which is not entirely clear in Bob’s out-of-context editing of my original statement), "

____ I much appreciate your higher than average quality of context, and am sorry for your correctly noted issue with my fairly regrettable edit-hack of your stated wording,, however I really didn't mean to actually-quote you out-of-context. _ But rather, I merely-just mean to only include just the posted wording which had inspired my response-wording. _ As whenever I really mean to actually 'QUOTE' anybody's post-wording,, I'll then make use of the provided 'Quote' feature, rather than merely reuse only-just their pertinent wording (as I most-often do merely as a springboard for my directly-associated responses).



" As far as speculating on GB market cam specs for the early Diana
I have no reliable figures on the GB market Daytona cam. It’s likely that the Daytona was the same specification as the US market Diana but I cannot state this with absolute certainty. "

____ That statement pretty-much reflects the same as what I-myself would have to say on the subject,, except I'd be sure to indicate that the "Diana" in question is actually the 'Diana 250' (just as Ducati had specifically named it !), and not the Mark-III version.
And also,, I'd make note that, (according to my '250 Monza' & 'Diana 250' parts-book), the Diana-250 camshaft is the very-same 'Violet' cam.model as the 250-Monza employs !
__ I once bought a basket-case collection of such 4-speed Monza & Diana models,, and all the camshafts I removed from the five cyl.heads, were the same cam.model, (so it didn't matter that I wasn't told which heads came from which-either 250-model).



" As far as the race kit cam for the first production Diana, this is steeped in mystery. The kit cam may well have been a red cam as standard in the Diana Mk III, but, again, I have no verifiable record of a cam that was positively identified as provided in the kit and reliably measured. "

____ Unfortunately I'm also in the same-boat on that enigma, but I was (at-least) once led to believe that the kit's main part was the Red-cam,, however I suppose that it could've just as well have possibly been the Motocross-cam, but I've tried that cam.model in Monzas and it (by itself) made no really noticeable improvement in power-output, (whereas the Red-cam certainly did !).



" the specification of the Diana kit cam may forever remain the subject of speculation. "

____ Sadly, that seems to be the case I'm afraid. _ As my original Ducati-mentor (and others who would've known of such), passed-away near 3-decades ago.
If only other old Duke-men (such-as John White, [of Domi Racer]), cared to add their knowledge here,, we'd then have lots of such mysteries forever enlightened for us-all !


Hopeful-Cheers,
-Bob