Vento 350

[graeme]

Hello Muz
I know the 450 scrambler cams I have came out of 450 scramblers.
They are 126mm long, is your 350 cam the same length?
I haven't had much to do with springer singles.
As for BOB'S comments re "real 450 scrambler" cams, I've never seen, or heard of the cam he describes.
Only the "everyday" 450 cam.

Graeme

[Muzz350]

Hi Graeme
The 350's cam is 126mm long.
Muz

[graeme]

I can send you the cam, try it and if you like the results make me an offer. (it's not worth much to me, so not expecting a lot)
If you don't like it, send it back.
PM sent
Graeme

[Muzz350]

Decided to post a pic of the cam profile while it is out of the bike.
Muz

[Muzz350]

Hi Bob
You may have noticed in the picture of my cam there is a small dowel or something inserted in the centre reducing the hole down to about 1-2mm dia. It is in both ends. What is it and is it fitted to all cams ? Can it be removed and inserted into another cam?
Muz

[DewCatTea-Bob]

" You may have noticed in the picture of my cam there is a small dowel or something inserted in the centre reducing the hole down to about 1-2mm dia. It is in both ends. "

____ Firstly,, I've been meaning to get-around to placing a post of my-own here ever-since I first noticed your posted-pic, and I still intend to do so (when I get more time),, but for right-now, I'll just address this specific subject (since that's all you've brought-up).
__ Usually these oil-flow reducer-pins are only placed at the threaded/outlet-end of the shaft, so as to cause the oil to more-so flow-through the outlets in the cam-lobes (instead of OVER-flowing on the bevel-gear and-thus provide oil disproportionally to the required places). _ But I've never seen such a flow-reducer located in the INLET-side of the shaft. _ It could be something that was done by Mototrans to help the bottom-end to receive more oil-pressure but, if the factory figured that more oil-pressure was needed, then they could've instead increased the size of the oil-pump,, so perhaps THAT extra flow-reducer was mistakenly added by someone-else. _ It looks as though the other Vento-cam (posted earlier) has one in that location as well though, so it could be just a cheap-ass way that the factory sought to better address the bottom-end.



" What is it and is it fitted to all cams ? "

____ I believe it's just a simple split/drift-pin that's press-fit into the center oil-passageway.
It's not regularly fit into ALL camshafts, especially the inlet-end !



" Can it be removed and inserted into another cam? "

____ Yes, or at least it's easy enough to remove when there's only one (at the threaded-end),, it may be an extra difficult task to accomplish when there's one located at both ends (depending on how stuck they are).
__ Do you have another camshaft which doesn't have such a reducer already installed ? _ If so, then I'd only install just ONE of them into it, at the threaded-end only.
If there's to be such flow-reducers located at BOTH ends, then I'd expect the one at the inlet-end to have a larger inner-diameter/opening (than the one located at the threaded-end).

____ Hopefully, somebody-else will have a better answer as to the actual reason for why your camshaft has such an oiling-impeding blockage at the INLET-end.


Dukaddy-DUKEs,
-Bob

[Muzz350]

On the outside of the cam bearing cover there is an oil pressure switch connected to a light on the dash. I was once asked how the Spanish developed enough oil pressure to operate the switch. A reducer in both ends is probably the answer. A side effect of this reduced flow may be the blueing I can see on the cam lobes.
Muz

[DewCatTea-Bob]

" On the outside of the cam bearing cover there is an oil pressure switch "

____ OH, I didn't know that model had such a function ! _ I guess that then explains the need for the extra-added oil-flow restriction-pin at the inlet-end.
__ So it now seems that YOU-yourself have come-up with the most likely reason for that added part (in THAT end of the shaft-way).



" I was once asked how the Spanish developed enough oil pressure to operate the switch. "

____ That does certainly seem to be a valid concern, as there's really not (normally) much oil-pressure for activating a pressure-sensitive switch...
__ Such an oil warning-indicator setup would have to be done that way IF it was intended to run a pressure-METER,, but otherwise, with just a mere warning-LIGHT, I really don't think it was very smart to force the oil to produce pressure for activating the pressure-switch, in the manor that they did. _ Rather, they ought to have employed a simple flow-lever to activate a switch (for the warning-light),, that way, any amount of oil-flow (regardless of the amount of oil-pressure), would've served well enough to let the rider know whether oil was flowing or not, (which is all a simple On/Off warning-light can tell ya anyhow).



" A reducer in both ends is probably the answer. "

____ Fairly likely so, but only for the odd-ball one added to the inlet-end,, as the other-one at the opposite-end of the shaft-way would-not provoke any significant added blockage-effect for the pressure-switch to detect.
The (more common) shaft-way reducer at the right-end however, would help to undo some of the negative-aspect caused by the EXTRA reducer added at the inlet-end.



" A side effect of this reduced flow may be the blueing I can see on the cam lobes. "

____ That tends to make fair sense, cuz if there's less oil passing-through, then the camshaft (as well as the entire top-end) would not be kept as cooled-off (by the flow of oil from the cooler oil-sump).
__ In order to employ a pressure-activated switch, then to help keep most of the top-end's supply of oil from being diverted to the bottom-end, another flow-restriction reducer-pin would have to be also added to the oil-inlet end of the crankshaft. _ So that (fairly likely) part addition ought to be checked for.
__ I would consider removing the reducer-pin from the inlet-end of the camshaft, and try to replace the stock oil-pressure sensor with a much-weaker/(MORE-sensitive) oil-flow switch, (so that the oil-warning setup could still function without that extra-added reducer-pin).


Dukaddy-DUKEs,
-Bob

[Muzz350]

__ I would consider removing the reducer-pin from the inlet-end of the camshaft, and try to replace the stock oil-pressure sensor with a much-weaker/(MORE-sensitive) oil-flow switch, (so that the oil-warning setup could still function without that extra-added reducer-pin).

I decided to simply remove the reducer pin and disconnect the dash light. It was laughably inaccurate anyway and singles have run well for years without it. It was a modern update with little benefit. I am trying a scrambler cam (courtesy of Graeme) with the internal valve springs removed. I’ll see how it goes in the traffic.
I am also fitting thicker steels to the clutch to get rid of the clutch creep in stop start traffic.
Muz

[DewCatTea-Bob]

" I decided to simply remove the reducer pin and disconnect the dash light. "

____ That's just as well, and probably what I'd do myself.
However I'd be sure to keep a flow-reducer in the right-side tip-end of the camshaft, so as to (at-least somewhat) help make sure that too much oil-flow isn't allowed to be diverted away-from the bottom-end. _ As it's fairly likely that a flow-reducer (of some sort) was also added to the oil-inlet on the crankshaft, (so as to also help raise the oil-pressure) as well.



" I am trying a scrambler cam
with the internal valve springs removed. "

____ That's good reasoning to eliminate the inner coil-springs, as the outer valve-springs alone should have no problem controlling the valves to remain loyal to such a mild cam's lobe-profiles.



" I’ll see how it goes in the traffic. "

____ For that kind of riding -(of intersection to intersection in city-traffic), there's no better camshaft for a 350-Duke to take full advantage of ! ... As torque/power-output from a stop to near 50MPH can't be surpassed by ANY other Duke-cam.model (in a 350, with a muffler) !
__ I don't know how noticeable the gain in acceleration will be for YOU to realize but, if your weight is under 200-pounds, then considering that you will have switched from an OVERly-wild cam to such a resonably mild cam, you thus-then really ought to notice quite a beneficial gain.
__ I-myself have already installed that same w-c.250-Scrambler cam-model in w-c.350-models, (which originally had one of the Green&White cam-models that are fairly wild cams, but not too AWFULly wild as the Lento-cam),, and while the resulting improvement in acceleration (with the milder cam) was not really very noticeable solely by the seat-of-the-pants pull, (since too much time passed between rides with the two different cams),, running against another (otherwise identical) stock-350 Duke-model however, much more-so then made the difference in acceleration quite obvious !
Furthermore, when running with mufflers, the stock 350-Duke (with a G&W.cam) seemingly inexplicably exploits no notable advantage over a 350 with a w-c.Scr-cam -(taken-from either 250 or 450 Scrambler-models), even at top-RPMs (since a muffler greatly curtails the superior high-RPM breathing which a G&W.cam can otherwise provide).
__ Bottom-line... Since you're switching from an even WILDER cam.model, you will certainly benefit from MUCH improved low-end torque/power-output, and also somewhat improved mid-range,, and at no really noticeably great loss in high-RPM power-output, (although the engine may no-longer rev as high, [at the top-RPM] ).
So this cam-swap should be a GOOD change for your 350-Duke !


Duke-Cheers,
-Bob