750 Camshaft Identity

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lavfancier

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Hello,
could anyone shed any light on the identity of cam shown below? The only numbers are stamped on the end as shown and appear to be KCF441. The 7/1 cam from the SF3  would appear to have more lift but less duration- also the 7/1 cam appears to be forged and this one appears to be machined all over and also the base circle seems a bit smaller.
It's out of I believe  an SF 1 engine of 153000 number range. The crankcases also have the number 6 or 9  stamped near the points area- any suggestions welcome.

LF
 

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hello LF,
I am guessing that you have added on too many zero's to the number, 750's did not get up to 20,000.  so......153??? could be about the change from SF1 to SF2 (from memory) The change is important because the SF1 (probably) had a factory fitted 5/1 camshaft and the SF2 (probably) had the 7/1 camshaft.Not easy to tell from the pictures but the profile does look like the SFC C5 shape because its not "pointy" anough for either of the other two, comparison needs to be done with a known source, i have my hands on a 6/1 right now and their ar no numbers as on yours, I have also checked the parts book and the camshaft part numbers for SF1 and Gt are nothing like that one posted, I cant say about the others.
CLEM
 
It looks to me like a genuine cam that has been modified for a different profile.
It is usual to take the base circle down to get more lift, or to regain lift from worn lobes.
They probably spun off the factory cam designation, and they have stamped their own code on the end.
I doubt very much anyone would have bothered to cast or machine from scratch a cam for an SF when replacements have always been available.
Whether you should try using it is a different matter.
 
i'm with tippie, the profiles don't look like any of the std grinds
the end being coded is a common way for marking a reprofiled cam
smaller base circle than std also suggests reprofile

as a guess the KCF is either the makers code or the customer initials
441 may be advertised lift or duration

many of the factory cams are unmarked
those that are usually have a stamping near a lobe not on the end

i recall sending jean-louis some end on lobe images against graph paper illustrating a variety of the 750 profiles
i think it got onto the old 'pedia wiki and i can't seem to find the originals in my files
perhaps someone else has them stored
 
That marking looks a lot like my local cam grinders - Kelford Cams in ChCh New Zealand.

Before you laugh and say that's quite a stretch, when i had customer cams reprofiled for a triple, they informed me they used to do Laverda cams for Harrie De Jonge....these days you never know just where some things have originated from.

Might be worth emailing them - easy to find their website on the net.

Greg
 
So, what would the KC 'F' signify?

:o Have you licked your fingers after holding those cams?

Actually, all jojes aside, I've got a set of 750 cams with no markings, I'm curious to know what they are too.
 
Chris,

Most unmarked Laverda cams are of the "8" type as fitted to the GT and GTL.  The factory probably didn't bother to mark them as they were the only ones in use at the time.  When the subsequent models arrived with different cams, Laverda realised they would need to mark them in some way.

There may be some rogue unmarked cams out there, but I doubt they would be stock factory items.

BTW, the pictured cam lobe is quite similar to a 2C(early 750SFC) or 4S(750S) profile. 

piet
 
Thanks for the advice folks, Kelford Cams in ChCh New Zealand as suggested by Greg looks quite likely
Check out thier web site:
http://www.kelford.co.nz/motocycles
I'll drop them a line shortly.

With respect to Clems comments regarding the number - yes I'm an order of magnitude out- engine number is in the 153xx range.

Here's another picture trying to show comparision of the 7/1 profile .

Anyone have any thoughts regarding the number stamped on the cases shown in the first post?
Cheers
LF
 

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profile does look like the SFC C5 shape because its not "pointy" anough for either of the other two
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Hi, Clem.

The profiles of 5/1 and 5C are identical, only the timing
is different.
If you look on a 5/1, the angle between the lobes is app. 90?,
on a 5C seems about 105?-110?.

Ernesto
 
Nice clear picture LF. Clearly shows the difference between the lobe shapes. The one closest to the camera appears to have a smaller base circle to give higher lift. The lobe looks wider too, which would give it longer duration, but that may just be an illusion because of the smaller base circle. Stick it in the bike and see what it does.

Cheers,
Cam
 
Dellortoman said:
Stick it in the bike and see what it does.

Cheers,
Cam
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Cam - Cammie thingies, go around and around, and around. And the armie thingies will go up and down, pushing down the springy thingies, that hold the stick thingies and then the whole lot pops up again. While the thingies on the other side of the chain thingie have a go too. :D
 
One can roughly say that Laverda started to stamp the cams in 1974, so most SF2, SF3, GTL, 16000-18000 SFC came with stamped cams.

Before that, all 750 cams 8, 4/S, 5/1 and 2/C came unstamped.

If you have f.i. a cam stamped 2/C, it will be a later produced (spare part) item.

Marnix
 
GregT said:
That marking looks a lot like my local cam grinders - Kelford Cams in ChCh New Zealand.

Before you laugh and say that's quite a stretch, when i had customer cams reprofiled for a triple, they informed me they used to do Laverda cams for Harrie De Jonge....these days you never know just where some things have originated from.

Might be worth emailing them - easy to find their website on the net.

Greg
Click to expand...
No luck with Kelford but Kevin Ban of Kelford juggested 'Kent Cams' in the UK- now why didn't I think of that???- anyway I contacted Kent and a nother very helpfull chap called Tony Woodward replied and confirmed that the marking was consistant with their's- all he could tell me was that it was a customer re-grind and has no idea of the timing but from his records suggested the lift was 8.1mm- I've done a quick check and that would appear close however  I looks more like 7.8mm on the Inlet and 8.0 on the Exhaust.- I'll set it up properly over the weekend.
Are the figures for timing in the Green book correct?- Does anyone have any lift figures?
Cheers
LF
 
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