From a press release:
DUCATI CORSE PRESS INFORMATION
DESMOSEDICI TWINPULSE ENGINE TO POWER DUCATI ATTACK ON MOTOGP CHAMPIONSHIP
Four-cylinder 989cc ‘L’ engine, with simultaneous firing order in cylinders of the same bank and desmodromic timing.
Track tests to get underway in July also in traditional firing layout.
Race debut with two riders at first round of MotoGP 2003.
Nine months after the start of the MotoGP project, announced last May at Jerez de la Frontera, Ducati Corse has completed the design stage of its new engine, called Desmosedici (16-valve Desmo), which will begin testing on the dyno within the next three months.
Ducati Corse Managing Director Claudio Domenicali explained the decision-making process behind the choice of the new engine:
“After analysing all the possibilities offered by the regulations and on the basis of computer simulations, we are convinced that a massive power output is required to be competitive in MotoGP. It would have been difficult to obtain this power with conventional twin-cylinder engines, which amongst other things are only given a 10 kg weight advantage over 4 and 5 cylinder engines in the regulations. As a result, the bore size would have to be taken to an extremely high value, with the risk of incurring serious combustion problems.
“For this reason, in the preliminary study phase, we considered a twin-cylinder oval piston engine to be an excellent layout for the new regulations. With the same weight as 4 and 5 cylinder engines, this layout combines the typical advantages of a twin in terms of power output and delivery, with the performance necessary to compete at the same level as the multi-cylinder units.
“But further analysis led us to decide that the best solution was a ‘double twin’ and therefore we designed an engine with four round pistons which, thanks to a simultaneous two-by-two firing order, reproduce the working cycle of a twin. This will generate the ‘big bang’ effect, making the rear tyre work in a way that extends its duration and improves rider feeling when exiting curves.
“The Desmosedici engine”, continued Domenicali, “will have a relatively short development period and reasonable costs and it will then be easily available also for external teams, since it is Ducati Corse’s intention to become a point of reference for private teams in MotoGP, as already it is in World Superbike.
“The Desmosedici power-unit, designed to tolerate the greater stress generated by simultaneous combustion, is therefore a unique engine with a further advantage: it allows two different versions to be tested. As well as the Twinpulse, we will also be testing a layout with a traditional firing order, which will have a slightly higher power output, but probably to the detriment of traction. Track testing and rider feeling will decide which layout will be used for racing”.
Another characteristic of the Desmosedici – designed by a team headed by Ducati Corse Technical Director Filippo Preziosi – is that it uses a desmodromic valve timing system, an exclusive characteristic of all Ducati engines for many years. “Thanks to this project, we are able to verify the Desmo’s true potential”, declared Preziosi. “Experience accumulated with materials and calculation methods on the Testastretta have allowed us to design an engine capable of exceeding 18000 rpm without all the costs and complications involved in using pneumatic valves”.
The first tests on the dyno for the new engine are scheduled for May and a track testing programme will get underway in July. The aim is to take part in the 2003 MotoGP season from the first round with a factory team made up of two riders.
Further information and regular updates on Ducati’s exciting new MotoGP programme will be given in the coming months and will also be available on the official Ducati Corse website: www.ducati.com/racing.
DUCATI DESMOSEDICI
TECHNICAL SPECIFICATIONS
Engine, four-stroke, four-cylinder ‘L’ (V90°, horizontal front cylinders)
Bore: n/a
Stroke: n/a
Capacity: 989cc
Expected maximum crankshaft power: over 161 kW (220HP) @ 16000 rpm
Expected maximum crankshaft torque: 100 Nm (10.2 kg/m, 72.2 lbs.-ft.) @ 14000 rpm
Timing System, double overhead camshaft, four valves per cylinder, Desmodromic timing with gear train
Cooling System, liquid-cooled
Ignition, electronic inductive discharge unit
Champion spark-plugs
Magneti Marelli stick-coils
Fuel System, Indirect electronic injection, Magneti Marelli
4 x Magneti Marelli single-injector throttle bodies
Exhaust, complete Termignoni system
Gearbox, six-speed, removable, front mesh