Compression release

[DewCatTea-Bob]

" Does any of you have a picture of the cable set up at or hear the valve on your bike you could E-mail to me ? "

____ It seems like somewhere in this forum I recall that there has already been posted a link (if not the actual picture), for that which you seek.
__The inner-cable goes through the tip-end of the lever & then through a small hole in one of the fins on the special-cover, where it's then clamped.

____ A good alternative for having a comp.release,
is to put the transmission into 1st-gear and roll backwards until ya feel the resistance of the compression, then you'll be at about the same desired-position as should be expected with the proper use of a comp.release! _ So from that point, you simply put it back into neutral & kick-thru .
This method is actually much easier for finding the optimum-position for the crankshaft-flywheel to be at, for then getting the best possible kick-over of the engine (through the very-next compression-stroke)!
I had to discover this method after I had installed a 100-thousandths over-size MC-piston -(which was 10.5:1 for a 250), in my first 350, which had no comp.release, (thus increasing the 'compression-ratio' to 13.5:1).
__ I'll admit that somebody who has developed an extra keen ability with the use of the compression-release, could possibly obtain a few degrees more of additional crankshaft-flywheel rotation, for slightly more advantage with the following kick-thru, but, that small extra difference is really not worth mentioning, (and I have only done so, so that nobody else will feel any need to make the point).


DUCATIly,
DCT-Bob

[Teckhardt]

Like Bob said, the inner cable is actually clamped thru a small hole in one of the fins. The outer sheath is what moves to press the lever down on the c/r.

Mine is all in pcs or I would take a pic for you.

I know I will take heat for it, but I am actually taking the c/r off of my 450. I got a new set of rocker covers off ebay and am putting a new set of levers on w/o the c/r. I am going to use the technique that Bob describes to find the proper kick-over. Personally I think the c/r spoils the look of the motor and it will be one less cable hanging off.

[DewCatTea-Bob]

" the inner cable is actually clamped thru a small hole in one of the fins. "

____ Ducati also made an egg-shaped bracket which could be used (in-place of a washer) on either of the two front cylinder-bolts. _ It's 3mm thick with two holes - one for the 10mm-bolt & one for the cable-clamp.
This allows more places for the cable-clamp to be located, since the lever-mechanism may screw-down to tighten-up & leave the lever-end facing towards other directions.
I've also seen the needed clamp-hole placed in the top (finned) fin of the head itself!


" I know I will take heat for it, but I am actually taking the c/r off of my 450. "

____ The actual-compression is very high with the extra mild-camshaft that's stock in springer-450s !
I highly suggest replacing the original-camshaft with a wilder cam! _ Preferably with the camshaft which was designed specially for the 450-springer Mark-3 -(non-'D').


DUKE-Cheers,
DCT-Bob

[Teckhardt]

I've also seen the needed clamp-hole placed in the top (finned) fin of the head itself!

Now that you mention it, that is the way mine was. Thru the top fin of the head.

I highly suggest replacing the original-camshaft with a wilder cam! _ (non-'D').

What would that do?

Preferably with the camshaft which was designed specially for the 450-springer Mark-3 -

Wasn't the Mark 3 cam the same as the SCR cam?

[DewCatTea-Bob]

I highly suggest replacing the original-camshaft with a wilder cam!

" What would that do? "

____ Concerning the topic, it would make the 450-springer easier to kick-thru the compression-stroke!
And also, a wilder cam would let the 450 breath more satisfactory. _ (As the stock-450's '250-SCR' cam is way too mild for a big 430cc cylinder!)


" Wasn't the Mark 3 cam the same as the SCR cam? "

____ I assume that you actually meant to ask: wasn't the 450Mark-3 camshaft the same cam used for the 450Jupiter/SCR ?
The answer to that is 'yes', that's how both models came stock from the factory!
__ I'm unaware if Ducati ever designed a cam just for the 450SCR, however they did design one specifically for the 450Mark3 !
My understanding is that the Italian-gov reps would not allow for the added expense of producing a camshaft just for that one model. _ So all 450-springer models had to share a camshaft with an existing model, and I guess Ducati chose the wide-case 250SCR-cam for the job.
That's really too bad, that it had to be that way! _ Cuz the 450 is really choked-off with that mild-cam!
For anyone who really wanted the '450-cam', it could be special-ordered... Off the top of my head, I believe that the part-# for that "450-cam" was either '0615.29.010' or '0616.29.010' . _ (The other number was for the '450DESMO-cam'.)
__ I already touched on this subject once before, (with more details), in another thread -(I think the one concerning Winter-Projects), after fellow-member 'Thevin' mentioned that he had a 450SCR to work on. _ So please read that post and then ask any further questions.


DUKE-Cheers,
DCT-Bob

[Pete]

Teckhardt,

Bob had mentioned that your 450 cam would work well in my 350. Let me know if you want to part with it.

Pete

[Teckhardt]

__ I already touched on this subject once before, (with more details), in another thread -(I think the one concerning Winter-Projects), after fellow-member 'Thevin' mentioned that he had a 450SCR to work on. _ So please read that post and then ask any further questions.

Don't know how I missed that thread. Good stuff there.

viewtopic.php?f=3&t=20

[Teckhardt]

Teckhardt,

Bob had mentioned that your 450 cam would work well in my 350. Let me know if you want to part with it.

Pete

If I end up putting another cam in, I will sure let you know.

[DewCatTea-Bob]

By Pete : ...
" Bob had mentioned that your 450 cam would work well in my 350. "

____ There were 3!,(maybe 4?) different camshafts which came stock in the various std.production 350-models, and only one of them was designed specifically for the 350 ! ...
__ The 350-Sebring came stock with the cam designed for the 250-Monza ! _ While that cam was a good middle-of-the-road design for a '250', it was really too mild for a 350.
Swapping the ('Violet') Monza-cam for the slightly wilder '250SCR-cam', would be a step in the right direction for that 350 -(which was stock with the 'Monza-cam')! _ However, the difference in performance is really not noticeably improved enough to make it worth-while to do such a cam-swap-job.
__ Most wide-case 350s came with the (G&W) '250F1-cam' - a cam that's so wild for a 250, that it's still quite wild even in a 350 ! _ Cams with such wild valve-timing do not work well with mufflers! _ So while that 'Green&White' cam is fine for racing, it really hurts a 350 for street-legal riding ! _ Thus swapping that cam for the w-c '250SCR-cam' would make a worth-while camshaft swap-job ! _ However you might not notice any big difference unless you do a high-gear roll-on against any stock wide-case 350, before & after, (as I have done several times!), to then witness the overall improved acceleration !
__ I have tried almost every std.production camshaft in almost every 250/350/450 model ! ... And so I know that a camshaft-swap between a (non-Sebring)/WideCase-350 & a 450-springer -(which were stock with the 250SCR-cam) will benefit the 450 even more than it benefits the 350 !
__ In my opinion, the '250Mach1-cam' is the best-choice overall for any otherwise stock std.production 350 ! _ Unfortunately, I don't have a great deal of experience with the fairly rare REAL '350-cam', as I only ever had just two of them. - The ('Green' ?) '350-cam' was originally designed for the 350Mark-3 and it's cam-lobes are about the average between the 'Mach1-cam' & the 'F1-cam'. _ Exactly which models of 350s actually came with the real '350-cam' has always been a bit of a mystery to me cuz the paint that's placed on the end of the shaft always seems to have come-off, and it's really not possible to tell one from a 'F1-cam' by just looking at it (since they're both so very similar!). _ I got mine from the early -(pre-'68 wide-case) 350-Scrambler -(which no 350SCR ever got a cam-design of it's very-own). _ Those '67 350SCRs came with 4-pole alternators and a lighter frame with squarish flat-U shaped fenders & the narrow-case SCR-gastank! - A fairly rare model ! _ Anyone else got one?
__ I stated that there are three different camshafts for the various 350 models because that's what I KNOW were imported into the U.S., and I indicated that there might be a 4th cam (for 350s) because, the Haynes workshop-manual (wrongly!) states that there were (only) two cams for all 350 models... Besides the well-known Green&White cam, Haynes also claims that some 350s used the 'White' (250SCR) camshaft.
I have NEVER found that milder cam in any stock 350 ! _ So I must assume that some of the Brit.versions came with that cam. _ If so, that makes real good-sense ! _ And I'm sure that Ducati had favored that choice for their 350SCRs, since that same 'White' camshaft was stock for all other wide-case SCRambler-models of any size !
As for why it seems that all the 350SCRs imported into the U.S. came with the wild cams, I can only point my finger at Berliner as the reason for that stupid choice for any 'Scrambler' type model ! _ As back in those days, your average cyclist simply assumed that wilder-cams directly-translated to 'Go Faster!' .
But in fact, those wild cams simply killed the (wide-case) 350's overall power (since they ran with a muffler) !
__ BTW, I got my idea of installing the 250SCR (White-cam) into 350s long before the Haynes book became available ! _ And I was surprised (somewhat delightfully) when I first read that info.

____ Well I've wondered off-track again as I'm apt to do, so I'll end this post now.
__ I hope to compile & post the specs of all the various std.production camshafts of every DUKE-model, some day soon.


DUKE-Cheers,
DCT-Bob

[Teckhardt]

____ Well I've wondered off-track again as I'm apt to do, so I'll end this post now.

Bob:

As far as I am concerned, you can wander off topic as much as you want. You keep giving us all great info. I just wish there was a way to we could database it all.