750 / 900 conversion, compatibility issues?

[stopintime]

If someone got a larger-capacity itch....

* throttle bodies fitment?
* exhaust port position (longer cylinders/heads)?
* belt covers ^ ? (do they even make carbon covers anymore?)
* 900 have adjustable cam pulleys?
* anything else?

[ducpainter]

All different...

No adjustable OEM pulleys on a 900.

Most people like a 5.5" wheel on a 900.

[Speeddog]

Between 750 and 900:

Throttle bodies are the same AFAIK.
Carbs are externally the same, a few different jets inside.

900 cylinders are ~10mm taller, so...
Exhaust port position is different.
Cam covers don't interchange.
Intake manifolds for carbies are different between 750/900.
I would suspect the ie manifolds are different as well.

My parts catalogues say '01 and '02 900's came with adjustable cam pullies, but AFAIK the 'small' (Non-DS) adjustable pullies are interchangeable with the fixed pullies.

[Speeddog]

Trans output shaft (coutershaft) is ~4.5mm rearward, as the trans gears are a bit larger on the 'big block'.

[ducpainter]

According to Ducati TB's are different...that might be because of the injectors.

Injectors are different between 750 and 900.

Manifolds are different

[brad black]

750/900ssie injectors are all the same, they're the old 851/907 green end flow.  the 750/900 monster has the later style brown pico, as do all 620/800/1000ss and m ie.

the throttle bodies would vary in the idle throttle stop base setting.

[ducpainter]

Any idea why the numbers are different Brad?

[brad black]

the throttle opening?  smaller engine needs less opening.

[ducpainter]

the throttle opening?  smaller engine needs less opening.

Actually I was referring to the part numbers in the .pdf files available from Ducati.

I suppose they could have all been updated by now as those original files are 12 years old. 

[stopintime]

Thanks guys 

So far this is what 'someone' got out of it:
* check hub position and maybe adjust height according to ~4.5mm rearward output shaft
* can use the same throttle bodies (from an S2R 800 = S2R 1000), but on 900 manifolds?
* modifying exhaust pipes, weld in a ~10mm piece - diameter is the same AFAIK

* aftermarket rearsets - two lower mounting holes the same?
* carbon belt covers unobtanium? ('forced' to go SpeedyMoto)
 

[Speeddog]

Not sure what would be the best route for fuel and spark, what ECU setup does the bike in question have?

Oddly enough, I've recently taken fairly accurate measurements, and yes, the lower rear mount points are the same.

I'm sure there are carbon covers somewhere, may have to get them second hand.

[stopintime]

Not sure what would be the best route for fuel and spark, what ECU setup does the bike in question have?
.........

800 DP ECU + PCIII

Decision has to made between built big bore 1000 (~1100) or 900 (~985).
The goal would be 110 bhp/Nm or 115 bhp/Nm for these two alternatives.

The largest option requires more exhaust parts/work (I guess), reflashed ECU for DS, other coils (?) and is generally more expensive. I'm not sure it's worth extra cost for the extra 5 bhp/Nm.

The 900 big bore can bump my torque from 91 Nm to 105-110 

If anyone questions my sanity... this isn't going to be as expensive as it sounds and I'll get a more reliable and robust engine.

[Speeddog]

OK, that's pretty much what I figured.

I'd go with a DS1000-based motor rather than a 900-based motor.

Heads come with 2mm bigger valves already, better ports, more fins and short exhaust port (better cooling).
IMO, a more durable package when it's all hotted up.
 
I'm not sure when the big motors changed to the Vacural thin-wall castings.
I'd stay away from building up one of those, I'm a bit suspicious of their durability.
No FHE, so if there's folks that are getting good results from those motors, I'd love to hear it.

Your sanity has never been in question. 

[koko64]

I approve of this project .
 

[stopintime]

..........

Your sanity has never been in question. 

Not sure about that