Making A Little Progress (with pics)

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guzzijon
Posts: 62
Joined: Wed Mar 07, 2012 12:55 am

Re: Top-end Parts Identification

Postby guzzijon » Wed Apr 18, 2012 11:32 pm

DewCatTea-Bob wrote:____ That's not where the factory-placed identifying paint-color is located on the camshaft !
I have no idea what that red-stuff is doing (where it is) on your cam, (as it shouldn't be there!).
__ Do you have a pic showing the shaft-end where the threads are ?


Sorry, no. But I just looked again and there is no visible paint-color on that end of the camshaft. So I guess I will assume it is the grey camshaft that matches the rest of the head until until I find out otherwise?
1963 (early) 250 Scrambler project
1964 250 Monza project
1981 Moto Guzzi Monza
1983 Moto Guzzi LeMans III

DewCatTea-Bob
Posts: 2897
Joined: Sun Nov 01, 2009 10:53 am
Location: Near SE side of Lake Michigan

Camshaft Identification

Postby DewCatTea-Bob » Thu Apr 19, 2012 2:51 am

" I just looked again and there is no visible paint-color on that end of the camshaft. "

____ That's usually the case with any camshaft that has over a couple thousand miles of normal-usage.



" So I guess I will assume it is the grey camshaft that matches the rest of the head "

____ I agree, as that seems to be what everything is pointing to.


" until I find out otherwise? "

____ That cam of yours is certainly either the red or gray version, and those two are fairly easy to tell-apart (when both are in hand), as the red-cam has a more impressive appearing exhaust-lobe. ...
Although the gray-cam has .5mm more valve-lift,, the red-cam's exhaust-lobe has slightly more duration, (which must be why it looks wilder).
The gray-cam is the one to hope for, as it (in my good opinion) is Ducati's magic-cam and it makes all 250/350/450 Duke-models perform BEST 'overall' ! - (Not meaning to be confused with HIGHEST peak-power only at top-RPM.)
__ If you have 1 & 2 inch mikes or a good caliper, then you could measure the min & max figures of the two cam-lobes and figure-out each lobe's lift-figure, to find-out for sure which camshaft you actually have.


Hopeful-Cheers,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob

guzzijon
Posts: 62
Joined: Wed Mar 07, 2012 12:55 am

Re: Camshaft Identification

Postby guzzijon » Thu Apr 19, 2012 8:38 pm

DewCatTea-Bob wrote:__ If you have 1 & 2 inch mikes or a good caliper, then you could measure the min & max figures of the two cam-lobes and figure-out each lobe's lift-figure, to find-out for sure which camshaft you actually have.
-Bob


I think I have a good-enough caliper but I need some instruction about where to measure on the cam and how to do the math after I've taken the measurements.

Thanks,

Jon
1963 (early) 250 Scrambler project
1964 250 Monza project
1981 Moto Guzzi Monza
1983 Moto Guzzi LeMans III

DewCatTea-Bob
Posts: 2897
Joined: Sun Nov 01, 2009 10:53 am
Location: Near SE side of Lake Michigan

Measuring of Cam-lobes on Camshafts

Postby DewCatTea-Bob » Thu Apr 19, 2012 9:47 pm

" I need some instruction about where to measure on the cam and how to do the math after I've taken the measurements. "

____ Okay, the 'cam' itself, (of which there are two on each camshaft), has a 'base-circle' where your measured-reading would be most MINimum,, and the 'cam' also of-course has a MAXimum measurable reading, which is taken between the max.peak of the lobe's tip-top end/side and the area/spot of the base-circle that's most opposite (180 from the lobe-peak).
So after obtaining the most minimum reading of the base-circle, (which should be found between two points that are 180-degrees apart,, on either side, away from the lobe's base),, that min.reading should simply be subtracted from the max.reading -(of base-circle combined with lobe-peak),
in-order to obtain the 'lift-figures' of your cam-lobes.
__ It may take a little playing-around with your caliper-tips placed flatly-against the cam's base-circle to base-circle (to get the min.reading), or flatly-against the cam's base-circle to lobe-peak (to get the max.reading),
in-order to get your BEST possible min & max readings.
__ A note about the "base-circle"... it's the area of the cam's follower-ramp which doesn't lift the rocker-arm, and is slightly greater in diameter than the actual 'shaft' itself,, (while the "lobe" includes the ramp-area of the cam which 'lifts' the rocker's cam-follower).
If you still have any questions (that my instructions failed to help make fully clear), then please ask for confirmation.


Hopeful-Cheers,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob

guzzijon
Posts: 62
Joined: Wed Mar 07, 2012 12:55 am

Re: Making A Little Progress (with pics)

Postby guzzijon » Fri Apr 20, 2012 2:56 am

Thanks! That makes sense. I'll take some measurements and report back.
1963 (early) 250 Scrambler project
1964 250 Monza project
1981 Moto Guzzi Monza
1983 Moto Guzzi LeMans III

guzzijon
Posts: 62
Joined: Wed Mar 07, 2012 12:55 am

Help with Cam Identification

Postby guzzijon » Fri Apr 20, 2012 8:44 pm

OK, I measured the lift and came up with 7.5mm or .295" for the exhaust lobe and 8.5mm or .335" for the intake lobe. The lobes themselves appear to be asymmetrical. Any ideas about what this cam might be? Thanks!
1963 (early) 250 Scrambler project
1964 250 Monza project
1981 Moto Guzzi Monza
1983 Moto Guzzi LeMans III

DewCatTea-Bob
Posts: 2897
Joined: Sun Nov 01, 2009 10:53 am
Location: Near SE side of Lake Michigan

Re: Help with Cam Identification

Postby DewCatTea-Bob » Fri Apr 20, 2012 11:58 pm

" I measured the lift and came up with 7.5mm or .295" for the exhaust lobe and 8.5mm or .335" for the intake lobe. "

____ That's really strange, as I know of no n-c Duke-cam with lift-figures same as those !
Are there any signs of wear ? _ If not, please list your base-circle readings, (as it may be possible that you somehow have a w-c camshaft).
____ The red-cam has ex.lift of 8.0mm, and in.lift of 8.5mm, while the gray-cam has lifts of 8.5 (exhaust-lobe), and 9.0mm (intake-lobe).
(The Monza-camshaft -[violet-cam] is the only cam I know of with just 7.5mm of lobe-lift.)
__ I'm thinking that you ought to try your measuring-task again some time, and then see if you get any different figures.


Dukaddy-DUKEs,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob

guzzijon
Posts: 62
Joined: Wed Mar 07, 2012 12:55 am

Measured Again...

Postby guzzijon » Sat Apr 21, 2012 8:23 pm

I measured again and came up with 8.0mm and 8.5mm. So maybe it is the "red cam"?
1963 (early) 250 Scrambler project
1964 250 Monza project
1981 Moto Guzzi Monza
1983 Moto Guzzi LeMans III

DewCatTea-Bob
Posts: 2897
Joined: Sun Nov 01, 2009 10:53 am
Location: Near SE side of Lake Michigan

Determining the Actuall Cam.model

Postby DewCatTea-Bob » Sat Apr 21, 2012 9:01 pm

" I measured again and came up with 8.0mm and 8.5mm. "

____ Okay, good,, that's a more likely actual combo. _ I gather you had made a subtraction-error before (for figuring your ex.lobe lift) !?
__ Anyway,, since the expected gray-cam is not confirmed, this now leaves two other camshaft-models to consider...
The red-cam and the rare camshaft which was unique to the WideCase-250Mark-3. _ These two camshafts are very easy to tell-apart, as their base-circles are much different !
As I look at your pix of your cam, it's not really very clear to me well enough so as to be SURE of which cam.model is pictured,, so that's a reason for why I asked you to provide the base-circle diameter that you've measured.
__ It's fairly disconcerting that your Mach-I type cyl.head doesn't seem to include the expected gray-cam, and-so if your particular cam is indeed a non-original model, then someone in the past must've replaced it's gray-cam with one of the two Mark-3 cam.models. _ Otherwise we're left with the seeming possibility that you still haven't reported the ACTUAL figures of your cam-lobes.
So do you have anyone-else who can try & confirm the figures you-yourself have come-up with ? - (If you had given me the base-circle dia.width, I'd know now whether this would possibly be of use or not.)


Hopeful-Cheers,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob

guzzijon
Posts: 62
Joined: Wed Mar 07, 2012 12:55 am

Base Circle Measurement

Postby guzzijon » Sat Apr 21, 2012 9:26 pm

I came up with 23mm as the base circle measurement. Also, this same head has the coil spring conversion on it. So that would point to someone messing around with it, maybe making a cam swap more likely?
1963 (early) 250 Scrambler project
1964 250 Monza project
1981 Moto Guzzi Monza
1983 Moto Guzzi LeMans III


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