Battery to an RT

[graeme]

Anyone fitted a battery to an RT?
I'm trying to figure out the best way to make a battery tray that keeps the battery down low so there's room in that area for ignition box and regulator. (and an after market air cleaner, like a cone shape k and n)
Any pictures?
The mounting points available are the top and bottom mounts from the original air cleaner, and maybe the seat bolts and possibly the top rear engine bolt.

[JimF]

Hi Graeme,

It sure looks light space is at a premium. I have no experience to offer, but If it were me I might fit the airbox and regulator and then perhaps out of cardboard construct the biggest box that will fit without physical conflict or airbox obstruction so as to know the maximum size of battery you might buy. That might also help you determine the location and size of shelf, as well as mounting points.

My Sport has its battery up high, virtually along the inside wall of one of the side covers. Any room there?

I am not sure how spill-proof/rupture-proof any of the many new families of sealed batteries (such as glass mat) are, but if you are willing to take a chance you might find some room up under the seat to stash a small battery on its side or with its terminals facing down.

I wish I had more to offer you!

What a clean bike you keep. I'd be happy if my singles looked half as nice as yours is.

Jim

[graeme]

Hi Jim,
It's clean because it hasn't come off the bench yet.

I think I've figured out a solution that will work and the vibrations won't destroy.
I'll post a picture later.

Graeme

[DanM]

You might want to consider one of new high tech batteries. They are about 1/3 the size and weight. But they are $$$.

Dan

[DewCatTea-Bob]

" so there's room in that area for ignition box and regulator. "

____ So long as the chosen battery is not too small, a regulator-unit is not really needed with a stock R/T alternator cuz it's lighting power-coil doesn't produce enough charging-power to over-power a battery (at regular-RPMs), especially with the lights running.
What IS needed is a full-wave rectifier-unit (connected to the outputs of that alt.power-coil).
____ As for battery installation,, due to 450-vibration, I'd suggest avoiding the solid-type of bracket-mounting (as on other Duke-models), and instead consider suspending your battery by rubber-straps hung under the seat (in front of fender).


Dukaddy-DUKEs,
-Bob

[graeme]

Hello Bob,
This RT has a Scrambler alternator and flywheel,
Reg. rec. from a square case twin,
Sachse ignition,
Acewell speedo/tacho/odometer,
Thus the battery.
None of the above make this a better RT than the next one, just easier to live with for me.

I've just about figured it all out, just waiting for paint to dry so I can fit it all together.
I'll post a picture when it's together, might help someone one day.
Graeme

[Eldert]

Hi Graeme

i had a look at the Sachse website and looked at the Ducati advance curves . ( i had to switch between German and English to look at al the curves )
you can choose from 32 to 39 degrees advance but a 450 needs less advance , somewhere around 28 degrees
i looked at al the advance curves from all the ignitions he sells and the Enfield would be more suitable for a 450
the advance curve runs from 28 to 34 degrees . i dont now if the black boxes are innerchangable but you could ask

Regards Eldert

[DewCatTea-Bob]

" you can choose from 32 to 39 degrees advance but a 450 needs less advance , somewhere around 28 degrees "

____ The stock advance-range is suggested to be zer0 to 28-degrees BTDC (by 3000-RPM), however
this is known to be a compromise of retention of the same preexisting AAU employed in other/earlier Duke-engines AND to avoid kickback (from the start-lever during starting).
It's been found that with that stock-AAU, a static-setting of 4-degrees BTDC yields the best full-advance performance, (of 32-degrees total BTDC).
So there's pretty-good reason to not stick with the original stock-range limit of only "28 degrees" !
Also,, in my-own opinion, the actual 'advance-curve' is not much of a concern so long as full-advance is reached soon-after kick-staring RPMs have been exceeded. _ As even radical differences in the 'curve' makes for near-insignificant changes in power-output (below 3000-RPM).
__ I haven't looked-over the offered AAU.curves but, for a 450, I'd recommend whichever comes closest to 2-degrees AFTER TDC (static), to 32-degrees before TDC (full advance), with the steepest/quickest climbing advance-curve.


Dukaddy-DUKEs,
-Bob

PS. I've added (an oversight) to my previous post.

[graeme]

Thank you for your advice Eldert and Bob,
Here are the advance curves available with this ignition.




A friend is using this ignition on his 450 desmo and likes it, that is why I bought it.
My '74 450 has the original Ducati Electronica red box, which works well, but it breaths better than standard.
The RT is standard.

Graeme

[DewCatTea-Bob]

" Here are the advance curves available with this ignition. "

____ None of all the 3-sets of adv.curves you've presented offer the optimum curve I-myself would choose for a 450-Duke but, the black-curve (in your top graph), if retarded 2-degrees, looks to be the closest/best-choice (of all those 12 choices), in regards to ign.advance-RANGE,
(of-course assuming that the limit of advance is indeed reached where the graph leaves-off).
However it's curve is not quite steep enough to suit me either,, as compared to stock (being at 28-degrees by 3000-RPM), the black-curve would be near 5-degrees retarded, (only reaching 23-degrees by 3000-RPM).
__ The pink-curve (in your center graph), is a little-bit steeper, reaching 26-degrees by 3000-RPM. _ But that adv.curve would only range-out to 30-degrees max, (if also retarded 2-degrees [so as to match the stock 0-degree static-setting] ).
So, either the black or the pink adv.curve would be a compromise, so it seems you have to choose between them by deciding which advantage (range or steepness) most appeals to your favorite preference.
Or perhaps you could ask if a customized adv.curve could combine the best of both black & pink curves ?
Still, I'd prefer an even steeper curve (than even stock), from 2-degrees ATDC to 32-degrees BTDC by 3000-RPM.
____ I wonder which of all those adv.curves Eldert (or anyone-else), thinks would be a best-choice !?


" A friend is using this ignition on his 450 desmo and likes it, "

____ Which adv.curve did he choose ?


Hopeful-Cheers,
-Bob