Green White Cam

Ducati single cylinder motorcycle questions and discussions, all models. Ducati single cylinder motorcycle-related content only! Email subscription available.
Moderator: Morpheus

Moderator: ajleone

Bevel bob
Posts: 1042
Joined: Thu Apr 15, 2010 8:01 am
Location: Bromley Kent UK.

Green White Cam

Postby Bevel bob » Thu Apr 15, 2010 3:48 pm

I'm currently running this cam on my M3Nc ,I understand its not much use with any kind of silencer, can it be adv/retarded to make it more useable? what are the clearances for timing this cam? ,what is the best cam ,grey/white ? Does anyone want a swap? .I'm currently running a Norton dommy cigar silencer which appears to work better than the std Silentium.

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

Re: Green White Cam

Postby DewCatTea-Bob » Fri Apr 16, 2010 3:28 am

" I'm currently running this cam on my M3Nc, I understand its not much use with any kind of silencer, can it be adv/retarded to make it more useable? "

____ DUKE-cams is my second-favorite DUKE-subject !
Now I understand that you have a narrow-case 250-Mk3 of which it stock-cam has been replaced with a Green&White-cam. _ And it seems that you may have read my report that these cams are only a disadvantage (overall, [compared to milder cams]), when matched with restrictive mufflers. _ While still somewhat true even with 250s, I only claimed so for 350-scramblers. ...
With 250s (vs. 350s), a 250 has 27% less exhaust volume to need to pass through the same (stock) muffler, and that helps allow a 250 to breath to a higher RPM (compared to a 350), so as to take better advantage of the G&W-cam's very wild valve-timing !
__ The G&W cam was originally made for the 250F1 production-racer, (which had no muffler to speak of), and so it's a very good choice for high-RPM road-racing (a 250Mk3, without muffler)! _ (The 250DESMO-cam is based on the F1-cam.)
Unfortunately, this cam is so wild towards either end, that neither advancing nor retarding it, will help any more than it would probably also hurt! _ If somebody were to mess with re-timing this cam to the crankshaft, I'd suggest retarding it about 5-degrees.
I know that there's been an offset-key made for doing so, (to be located at the crankshaft and/or the camshaft's key-way/slot). _ I've used such keys to play with the valve-timing but, I never noticed any real change. _ I guess a dynamo-meter is the only way to know for sure if ya have made any worth-while improvement (instead of hurting overall-power).


" what are the clearances for timing this cam? "

____ They're the same figures given for the '350 Scrambler'. _ Unfortunately, I know that there were (at least) two different cams that were stock in 350-models with that very same name !


" what is the best cam , grey/white ? "

____ In my opinion, the 'Grey' (Mach-1) cam is Ducati's magic-cam ! - It allows the best overall-power. _ Your next best choice (after the stock 'Red' Mark-III cam), would be the 'White' cam, which is stock to the wide-case 250 & 450 Scramblers.

____Wondering how your Mk3 ended-up with a G&W-cam in place of it's stock-cam?


DUKE-Cheers,
DCT-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

Bevel bob
Posts: 1042
Joined: Thu Apr 15, 2010 8:01 am
Location: Bromley Kent UK.

Re: Green White Cam

Postby Bevel bob » Fri Apr 16, 2010 7:52 am

The M3 has been ported and modified and rebuilt and indications are that it was once a racer,then rebuilt and re registered for road use, It now starts ok pulls well enough to spin the rear on take off and revs climb very fast to 10 k if i'm not carefull so with your comments in mind I wont stress over the cam, I will keep looking for a M1 cam though.What silencer would you recommend ? the Norton one is much bigger bore than the silentium and seems to work well (designed for 300 cc cylinder).I dont know yet how much power there is as I have issues with the primary gears to sort out.

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

Re: Green White Cam

Postby DewCatTea-Bob » Sun Jun 13, 2010 8:22 am

This post takes-off from the 'Points Adjustment' thread (which has some related info left-out here)....


" And if you have the spec figures for any or all, how they differ from one another and if those differences are good or bad for whatever, etc. "

____ The first 350 -(narrow-case Sebring) had the same cam & valve-timing as the 250-Monza !
That has the exhaust-valve opening at 50-degrees Before-Botton-Dead-Center (when the power-stroke has about finished).
Then next the intake-valve opens at 20-degrees Before-Top-Dead-Center and then the exhaust-valve closes at 30-degrees After-Top-Dead-Center. - (This short period when both valves are open at TDC is called 'overlap', and in this case it's 50-degrees long.)
Then next the intake-valve closes at 70-degrees After-Bottom-Dead-Center. _ (And then the spark occurs as soon as 70-degrees later, just before TDC.)
__ That 'Monza' valve-timing -(in: 20-BTDC to 70-ABDC & ex: 50-BBDC to 30-ATDC) provides an intake-duration of 270-degrees and an exhaust-duration of 260-degrees, which is not very mild for a 250 but it's quite mild for a 350 (which also has the same size plumbing -[so-to-speak].)
__ The 'Monza-cam' is identified with violet-paint and by it's 'lift' of 7.5mm for it's intake-lobe & 7.2mm for it's exhaust-lobe.
__ The wide-case Sebring-cam has an intake-lobe lift of only 7.4mm, and it's valve-timing is: in. 22-60 & ex. 51-28, thus providing 262-degrees of intake-duration & 259-degrees of exhaust-duration, (even milder!), but also with 50-degrees of overlap, (as the narrow-case version has).
__ Either version of this cam makes a fair choice for a 350-DUKE that's intended to be used for quick stop-&-go type city-driving and/or where better fuel-mileage is desired, or for best hill-climb chugging.

____ Next 350-cam was the one used for the 1967 350-Scrambler (which was the first std.production wide-case 350 imported into the U.S.A.).
This cam's timing is: intake 65-BTDC to 76-ABDC & exhaust 80-BBDC to 50ATDC, which provides an intake-duration of 321-degrees, a (wild) overlap of 115-degrees, & an exhaust-duration of 310-degrees.
__ Anyone who understands this cam-timing tech very well, will realize that this cam is in no way suitable as a 'scrambler' type cam !
(I have had fairly-good reason to believe that this particular cam was originally designed for use in a planned [but never released] narrow-case 350Mark-3, as it's specs would be pretty-much perfect for a Mark-3 type 350 ! )
__ This 350-cam is the "real" w-c '350-cam' ! _ And for most 350s, was (stupidly) replaced with the '250F1-cam' sometime by late 1968, (and still left to also be referred to as 'Green & White' !?).

____ The next 350-cam was actually the 250F1-cam, which has valve-timing of: in. 70BT - 84AB & ex. 80BB - 64AT, and provides an intake-duration of 334-degrees, a (too wild) overlap of 134-degrees, and an exhaust-duration of 324-degrees.
__ This cam's specs certainly make it qualify as an all-out 'racing-cam' for a 250 ! _ And even in a 350, it's still quite excessively wild !
Anyone who has good experience with valve-timing tech should realize that this cam is TOO wild to obtain the full advantage of what it's actually capable of performing (only at high-RPM), while also running with a std.muffler ! _ In fact, running this F1-cam with most any muffler will not only cut-down it's intended ability to increase a 350-DUKE's peak-power, but ANY other std.DUKE-cam you could get would provide an increase in overall-power (when running with whatever muffler) !
It's so incredibly crazy that Ducati installed this extremely wild cam into any Scrambler-type model ! _ I'm sure that they only did so with the 350SCR/SSS because Berliner stupidly requested for the factory to do that for some inexplicably dumb reason.
Many (unenlightened) people think that hotter/wilder-cams will always make engines go faster but, that's not always the case under all circumstances ! _ As cams which are TOO wild, can actually loose a race against much milder cams, (all else being equal).

____ The std.DESMO-cam -(which is actually the '250-DESMO cam') stock in 350-DESMOs, is coded Blue&White, and was based on the 250F1-cam,, with both having about the same 'lift' of 10mm for the intake & 9mm for the exhaust.
It's valve-timing is: in. 70 - 82 & ex. 80 - 65, which thus provides an intake-duration of 332-degrees, an overlap of 135-degrees, and an exhaust-duration of 325-degrees... Which considering that Ducati states that their actual cam valve-timing figure-specs are within +/- 5-degrees, SEEMS to indicate that the std.DESMO-cam has no high-RPM breathing-advantage over the '250F1-cam'. _ However the valve-timing & lift is not the whole-story ! ...
The DESMO-cam opens & closes the valves at a slightly faster rate, thus it's 'Average-Lift' is somewhat increased, over the F1-cam's ! _ And while that added slight difference does indeed provide an extra breathing advantage, it's nothing to get too excited about, because you'd need a dynamometer to realize any increased power difference, due to that slight advantage alone.

____ The final cam which I'm aware of being stock in some 350-DUKEs is the 'White-cam'...
The White-cam was first used for the late 1968 wide-case 250-Scrambler ! _ And that cam was very well suited for a SCR-type model ! _ Which is why I have believed in the past that it was designed specifically for that particular 250-model, (however, there are clues that could lead one to think that the White-cam may have actually been originally designed with the 350-Scrambler in mind!).
__ The valve-timing of the 'White-cam' is: in. 27BT - 75AB & ex. 60BB - 32AT, which provides an intake-duration of 282-degrees, an overlap of 59-degrees, and an exhaust-duration of 272-degrees. _ And as I recall, it's lift is 8mm for the intake & 7.6mm for the exhaust - (I might have those lobe-figures .1 to .2mm too high... I won't be positive until I mike one again).
__ This same cam was also definitely used for the 450-Scrambler/Jupiter as well, although, I believe it to be much too mild for a 450, even if a SCR-model ! _ And while I've never actually had my hands on a cam removed from a 450-Mark-3, I understand that even that 450-model inexplicably came stock with the White-cam also,, and that's way too much extra mild for a 450-Mk3 model ! - (The 450Mk3 was supposed to have it's very-own cam!)
__ Now while I myself have installed the White SCR-cam into (otherwise stock) 350-Scramblers, (with very-good results), I've never found one in any stock-350, and I doubt that any 350s were imported into the U.S.A. with this cam, (no doubt due to Berliner's whim).
The only reason why I believe that the 'White-cam' was ever installed by the factory into some of their 350s, is because I've read so, in British sources that it was,, and it also stands to good reason that Ducati themselves would've chosen to also use the White-cam in the 350-Scrambler as well, since they did indeed choose to use it for both their 250 & 450 Scrambler-models !

____ I fully welcome any comments about anything I've written within this post ! _ So please do so, if you're at all inclined.


DUKE-Cheers,
DCT-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

Eldert
Posts: 771
Joined: Sun Nov 01, 2009 3:23 pm
Location: Hazerswoude Rijndijk Netherlands

Re: Green White Cam

Postby Eldert » Sun Jun 13, 2010 3:22 pm

the specs for camshafts are given most of the time at 0.040 or 1 mm ( thats about the same ) like Megacycle
some cams like the Norris N 390 and VEETWO are taken at 0.020 or 0.5 mm

so if you want to compare timing figures from cams make sure the readings where taken with the same clearance

here are the timing figures for a green /white cam i have taken myself at 1 mm
intake opens 41 degrees btdc and closes at 64 degrees abdc
exhaust opens 66 degrees bbdc and closes at 29 degrees atdc

the most used method how to determ the cams position in relation to the crankshaft is by calculating the lobe centres
it goes like this : opening + closing + 180 so 41 + 64 + 180 = 285 degrees duration . devide this by 2 and subtract the opening figure for the intake lobecentre . so 285 : 2 = 142.5 - 41 = 101.5 intake lobecentre

for the exhaust lobecentre do the same but subtract the closing figure so 66 + 29 + 180 = 275 degrees duration
275 : 2 = 137.5 - 29 = 108.5 exhaust lobe centre

if your cam timing is way off you can go 1 tooth one way on the bottom bevel gear and 1tooth the other way on the upper bevel gear . this changes your camtiming 8.6 degrees . you can make smaller changes with offset woodruffkeys like
Bob allready mentioned

Eldert

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

Re: Green White Cam

Postby DewCatTea-Bob » Sun Jun 13, 2010 8:59 pm

" here are the timing figures for a green /white cam i have taken myself at 1 mm
intake opens 41 degrees btdc and closes at 64 degrees abdc
exhaust opens 66 degrees bbdc and closes at 29 degrees atdc "

____ I have never tried to measure a G&W-cam's valve-timing using that largest -(1mm) std.clearance setting but, I'd very much trust Eldert's readings even if I can't confirm them !
With those particular valve-timing figures which Eldert found, it's quite clear that Ducati itself did not get their own published spec-figures while using such a large preset-gap !
__ Another concern that's left due to Eldert's relatively mild figures (for a G&W), is exactly which camshaft he actually measured.....
Eldert, could you please tell us exactly how you determined that the cam which YOU measured is actually a real Green&White-cam? _ Did it still clearly have it's ORIGINAL factory paint-code on it? _ Regardless of any paint-code found, did you measure it's lobe 'lift' figures to confirm that it was indeed a true G&W-cam?
Also, WHICH "green /white cam" did you think it actually was, which you obtained your figures with? ... The real '250F1-cam', or, the original wide-case 350-cam? - (As either has often been referred to as a 'Green/White-cam' !)
These details should be KNOWN before your figures can be truely useful.

____ I don't actually question anything done by Eldert, as he's one of few who I'd really trust to do most anything, other than doing for myself. _ I'm just trying to make sure that all-the-cracks-are-covered here.


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

Eldert
Posts: 771
Joined: Sun Nov 01, 2009 3:23 pm
Location: Hazerswoude Rijndijk Netherlands

Re: Green White Cam

Postby Eldert » Sun Jun 13, 2010 9:24 pm

Hi Bob

i bought a brand spanking new g/w cam and a new grey cam from a old Ducati dealership in Germany for referance
the used cam i measured was a g/w cam for sure . the paint marking where still on it
intake camlift is 9.9 mm exhaust lift = 8.55 mm
the cam is not really mild at all . if you go to the megacycle website and look up the specs for their 564 00 camshaft
www.megacyclecams.com/
( witch is a copy of the orange /white factory race cam ) the opening duration @ 1 mm lift is 2 degrees less then the g/w cam . the g/w cam has a little less exhaust duration then the racecam g/w = 275 degrees 564 00 = 302 degrees

Eldert

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

Re: Green White Cam

Postby DewCatTea-Bob » Sun Jun 13, 2010 10:41 pm

" the used cam i measured was a g/w cam for sure . the paint marking where still on it
intake camlift is 9.9 mm exhaust lift = 8.55 mm "

____ I really did not doubt that the cam you measured was actually a 'G&W-cam', Eldert. _ I was only concerned as to whether it was actually a '250F1-cam' or a std.wide-case '350-cam'.
The lift measurement-readings which you've stated, indicate to me that it's the w-c 350-cam, (not the F1 version).
Do you have more than one G&W cam handy, to check?


" the cam is not really mild at all . "

____ OF course ! _ Neither of the G&W cams are mild ! _ (I had used the word "relatively" as a qualifying-agent.)


" the g/w cam has a little less exhaust duration then the racecam g/w "

____ Do these words of yours mean to indicate that you agree that there's more than just one 'Green & White' camshaft ?


"( witch is a copy of the orange /white factory race cam ) "

____ The O&W factory race-cam is one camshaft which I've never had my hands on !
Could you please tell us all you know of it?
Is it the same as a 350F1-cam?


DUKE-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

Jon Pegler
Posts: 459
Joined: Sun May 16, 2010 6:19 pm

Re: Green White Cam

Postby Jon Pegler » Sun Jun 13, 2010 11:08 pm

The orange and white cam was a standard fitment on the Spanish Vento and some Forzas.
It is a truly wild cam with 152 degrees of overlap. Makes a Manx Norton look a bit tame. All top end with very little response below 4500- 5000 RPM.
It has a noticably different profile to the green and white cam when the two are compared.
Only really suitable with a long megaphone or even longer straight pipe.
Quite why Mototrans decided to use it is a bit of a mystery. It is so unsuitable for road use. I know. I've tried it. It is hard work buzzzing the engine so much, all the time.
I've got a couple if anyone need any measurements.

Jon

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

Re: Green White Cam

Postby DewCatTea-Bob » Mon Jun 14, 2010 12:19 am

" The orange and white cam was a standard fitment on the Spanish Vento and some Forzas.
It is a truly wild cam with 152 degrees of overlap. "

____ Wow, thanks for that Jon ! _ You've not only filled-in some blanks for me but also solved an old mystery for me as well !
(I had figured that Eldert would be the only one of us who might know of any such good-info about this particular subject.)
The mystery for me was how the claimed far-out valve-timing for the 350-Vento (in. 72 -100 & ex. 98 - 80) could even allow it to run half-way decent with any muffler ! _ I've now learned that in fact it doesn't.
Until you confirmed what you have, I had assumed that those valve-timing figures given for that particular 350-model by Mototrans, were either somehow in error or had been taken/read while the valve-clearances were still left set at normal running-clearance.
__ I'm now able to realize that those particular timing-figures are so far-out wild because they're actually the same spec-figures for the Orange&White 350 racing-cam, of which I had also never knew of for sure before !
So it's now very nice to finally learn for the first time that the stated cam spec-figures for the Vento are actually not incorrect, and also learn what the timing-specs actually are for the O&W-cam as well, all at once !
So thanks again very much for that info !


" I've got a couple if anyone need any measurements. "

____ When you get a chance Jon, please see if you can mike your two O&W cams to see how much lift they have for both intake & exhaust.


THANKS,
-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


Return to “Ducati Singles Main Discussions (& How to Join)”

Who is online

Users browsing this forum: No registered users and 55 guests