The 2011 Ducati Marlboro Desmosedici GP11 will likely be fitted with an updated version of the big bang engine based on the feedback from Valentino Rossi and NIcky Hayden after two days of testing in Valencia, Spain.The two-day test at the Ricardo Tormo Circuit in Valencia, Spain was meant to familiarize Rossi with the Ducati, while also giving him and teammate Hayden time to thoroughly test both the screamer and big bang firing order engines. Hayden finished with the sixth fastest time, while Rossi was down in 15th and 1.7 secs. off the pace set by the rider he replaced, Casey Stoner, who set the fastest time of the test on his new Honda RC212V. Rossi continued to be bothered by his damaged right shoulder, which he stressed with 70 laps today. He's expected to have surgery early next week in Milan. Ducati's Filippo Preziosi had previously said he'd asked Rossi to sacrifice an outright lap time for the sake of choosing an engine, which Rossi was more than happy to do, though Rossi did find the front end needed work. Both Stoner and Hayden had a number of front end crashes this year, but it wasn't known if Rossi was having the same issues.When Preziosi was asked which engine configuration would be built for the two factory and four satellite bikes, he replied, "I think big bang, but we have not decided. We have to do a meeting, but I will suggest big bang." Preziosi pointed out that Hayden and Rossi preferred the 2011 big bang firing order to the 2010 firing order. "This is sure. The screamer have a good potential from top speed, stuff like that, but less drivability. So I think we have not tested properly. So if we have to decide now, maybe we will go with the big bang 2011."Hayden said he "felt more comfortable with the big bang on this track. I mean, you know, this track, the screamer, where it's good you don't get to use it except one place," on the front straight, "so they need to go back and check the data and check the calculations and stuff and not just jump to a decision just yet. But it's pretty clear at this moment if I had to choose for the race, I would go big bang. But I went pretty decent. Today, lap time was close with the screamer, so it's not unrealistic to think it couldn't be an option."Asked what the advantage of the screamer was, Hayden said, "Other than the sound," to hoots of laughter, "because I've never ridden a 500, but I can imagine it's like a just... When you want something it's right there. Obviously, the sound, as great as it sounds, we've checked: It doesn't help the lap time," he said to more laughter.What wasn't a laughing matter was the front end trouble Rossi was having."I think we have to work on the position of the rider into the bike," Preziosi said. "The stiffness of the front part of the bike and the weight distribution and the geometrical and the weight distribution, so there are some things we have to work on."Rossi told Preziosi he liked the rear tire grip, because he'd struggled with Yamaha grip. Rossi also liked the engine and the traction control-Ducati is renowned for their electronics prowess-but "he has not good feeling from the front and I think we have to work for that, because with that kind of tire it's very easy...if you are not believing in the bike, you are not pushing. If you don't push, the temperature of the tire goes down and without the temperature the tires are not performing. And if the tires are not performing, no way to be fast. So this is the mechanism that we know very well."Preziosi repeated his first impression of Rossi from Tuesday, that he was again impressed with the process the nine-time world champion employed."What is unbelievable is his way of doing the test and how positive he is. Yesterday I was surprised about how clinical he is in telling every detail, but today I was really astonished about how he's positive and calm," Preziosi said. "It's very strange for a person that is so winning a guy and have a bad test, no. I was expecting a person that was telling us 'What kind kind of bike you have done?' Or something like that. Maybe this is the reason he won nine world titles."