Much speculation attends the precise nature of the Ducatis ridden by Doug Polen. On the one hand, I have reason to believe Eraldo Ferracci has not used the heavy Pankl (Austrian specialist company that makes rods for F1, &c.) rods, choosing semi-production Carrillo steel rods instead. The story was that the Pankls used smallish, non-multiphase-material capscrews that occasionally broke. Can't have that.
Now I hear that Ferracci has had titanium rods made, perhaps even lighter than his previous Carrillos. Ferracci has a long list of suppliers from whom he gets lots of things -- suppliers other than Ducati. Ex-factory rods in Titanium, without up-the-shank oil feeds to the wristpin, are reputed to be 9 mm longer than stock. Private runners report power gains with +5 mm rods.
Several years ago, John Wittner noted that Ducatis have a crankcase pressurization problem. He suspected that their combination of flexible, light pistons and heavy Pankl rods was causing enough dynamic distortion to cause this. Pable Real says the bigger the bore is made, the more the cylinders warm out of round. Both may be right; certainly Ferracci must have had reason not to use the stock-issue con-rods. Adamo had said that certain piston-ring sizes worked better to seal the engine than others. Is this different suppliers?
Ferracci told me a couple of years ago that the con-rod oil feeds weren't necessary if the piston and wristpin materials were right. Recent-type piston designs locate their wristpn bosses on free-standing pegs that are thermally coupled more to the piston dome than to its skirts, as in older designs. This raises wristpin boss temperature, no doubt leading to problems. Such oil feeds were a feature of some WW II aircraft engine con-rods, incidentally.
Speculation is that Ferracci is using 37/31 mm intake/exh valve sizes, which would require (to avoid valve shrouding) something like a 96 mm bore, for a displacement of 926.5 cc. At Daytona, the rumor from the late Jimmy Adamo was 95.6 mm - close enough. That would make the engine 917 or so.
Horsepower rumors? I repeat this not in hopes of finding believers, but just because these are the numbers I most recently heard rattling among the grape leaves; 149 for the top bike, and 120-125 for "selling-bikes".