Porting and Polishing the 907ie?

discussions specific to the 907IE
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Frenchy
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model: 907 I.E.
year: 1993
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Porting and Polishing the 907ie?

Post by Frenchy »

Nubile with power tools here. Seems everything else on this bike can be modified. Limited information on the net from my limited research. I realize I may be entering an area of the Dark Arts and I prefer to not being the one to re-invent the wheel. Before I break out the dremel get into a bunch of trouble, I am just wondering if any ducatisti has had success in this area with the desomdue?. Yes, I know it's not a demodechi, it's a sport tourer, but I still want more response with dependability. Old schoolers feel free chime in. Kawasaki factory racing used to shave a milimeter off of the pistion just above the exhaust port. I Really don't want to screw this up and have to shop for new jugs or heads. I understand less is more but I have an itchy trigger finger. Pics would be great!
Mc tool
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Re: Porting and Polishing the 907ie?

Post by Mc tool »

I have a friend who is (really really ) into racing his 900ss ( same motor just air/oil cooled ) and he says the single best mod for a roadie is to fit a larger bore primary exhaust header. He originally fitted his while running FCR's and kept them when he fuel injected it ( not sure what system he used , probly a combo , but I know the parts were all Ducati stuff ) . If you are after more response rather than more power , I would investigate tinkering with the fuel injection rather than the irreversible ( and often unnecessary ) port work :)
I wish I was young again............Id be heaps smarter than last time
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paso750
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Re: Porting and Polishing the 907ie?

Post by paso750 »

angelix
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Re: Porting and Polishing the 907ie?

Post by angelix »

although the V2 is limited (long stroke, small valves, bad cooling), lots can be done but the gain is not worth the money spent, in mi opinion...

The very best mot is fitting a set of ST2 Camshafts and tuning the ECU, it simple that mod the character of the engine changes considerably without becoming unpleasant at slow speeds.

I would not port the heads, I would simply clean & smooth them and make sure all is well matched

One mod I would do is fitting new adjustable cam pulleys which allow the resetting of the camshafts the "proper way"; it is a simple upgrade and quite in expensive, all modern 2Vs have them and they are all interchangeable.

I would then fit a nice set of ST2 cams and while I have the heads in hand I would make sure both are matched (chamber volumes and squish), the valves and seats are well machined and I would prepare properly the intake valves.

I would give a light smoothing & polishing to the heads and insure the intake headers are matching the ports and that is it.

That is a bike that needs to be smootha and sweet to ride, not a racer...
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ducinthebay
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Re: Porting and Polishing the 907ie?

Post by ducinthebay »

For the most part, you would do well to clean up the intake ports and manifolds so they at least matched each other and had smooth transitions. The harsh steps will create eddie currents and disrupt flow. After that, put the dremel away. Not much to be gained, plenty to be lost, and it takes years of experimentation and experience to develop anything better than stock.

I cleaned up the intakes on the Sport, and it did improve things, but just a bit. I didn't get anywhere near the valves though. Just the transitions from the carb to manifold to head. Just cleaning up the roughness of manufacturing.

Cheers, Phil
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
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paso750
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Re: Porting and Polishing the 907ie?

Post by paso750 »

ST2 cams are really hard to find and then usually too expensive. The 900ie cams are very similar.
As Phil said there`s much to be ruined if you don`t really know precisely how it has to be done for the best outcome.
I know some guys that removed the cylinder base gasket but that requires a groove to be machined in one cylinder (I can`t recall which one) so an o-ring can be fitted.

G:
Tamburinifan
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Re: Porting and Polishing the 907ie?

Post by Tamburinifan »

No Oring needed when removing cylinder gasket.
Gert

907 I.E. -91
M900 -97
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paso750
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Re: Porting and Polishing the 907ie?

Post by paso750 »

chances are with metal on metal that you`ll have a leak from an oil channel so it`s better to do it.
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