Ducati Unveils V-4 Desmosedici Stradale Engine At Misano MotoGP

Every 30 years or so, Ducati marks the progress of motorcycling engineering with a staggering new concept that remains a reference point in the history of mechanical engineering. First it was in 1954, when Dr. Fabio Taglioni developed a desmodromic valvetrain so logical and linear that it could be adopted on regular production engines, and from then on Ducati became the universally recognized desmo specialist thanks to his genius.

Then in 1987 Ducati developed desmodromic actuation for four-valve induction. This was a common effort based on Massimo Bordi’s graduate thesis that was supported by the same Dr. Taglioni, who mentored the young student at the University of Bologna. In fact, Bordi presented Dr. T’s drawings with his thesis, and then Dr. Taglioni hired Bordi at Ducati.

The task of making the four-valve desmo concept production-ready was handed to Dr. Gigi Mengoli. The desmo four-valve distribution progressed dramatically through all these years to the point of granting impressive performance superiority to both the Panigale 90-degree V-twin and to the Desmosedici GP17 racer, the latter capable of almost 20,000 rpm.

Based on the experience gathered from this impressive V-4, now it’s current Ducati CEO Dr. Claudio Domenicali’s turn to leave his signature to mark yet another ultra-sophisticated turning point in the evolution Ducati’s engineering tradition. As Domenicali announced at Mazda Raceway Laguna Seca during the World Superbike round last July, the 1199/1299 Panigale Twin hands the torch to a radically new 90-degree V-4 Desmosedici Stradale engine that appears surprisingly compact and light for its 1,103cc size.

This is no other transition: The Panigale is the most advanced and the hottest performing twin cylinder engine ever. Ducati V-twin fans are going to miss it, though its smaller brother the 959 will stay with us. Still, fans will miss the extra cubes and those 116mm-diameter pistons that look borrowed from a Chevy Can-Am Big-Block V-8.

But this is the engine that hopes to be a worthy replacement. This new Ducati V-4 features an 81mm bore that it shares with the MotoGP unit to underline the strict relationship of the respective valve and combustion-chamber designs. The stroke grows from the 48.5mm of the racing unit to 53.5mm to obtain a displacement a whisker past 1.1 liter. This displacement choice seems to indicate that Ducati might leave the Superbike scene to focus solely on MotoGP, but a shorter-stroke 1.0 liter version could be developed in a matter of weeks.

The new Ducati 90-degree V-4 adopts a crankshaft with the two crankpins set at a 70-degree angle to obtain a perfectly balanced V-4 with no need to resort to power-robbing balancing shafts. This is a very innovative crankpin arrangement, and it follow the same balancing theory that we have seen applied by Honda to its NC700 and latest Africa Twin parallel twins. In this case the Ducati technicians aimed at balancing each pair of parallel cylinders and then balance the complete V-4 like a 90° V-twin. According to Ducati its new V-4 Stradale engine is perfectly balanced for both comfort and mechanical efficiency, another major factor since the engine will be able to spin past 13,000 rpm.

The firing sequence is 0°-90°-290°-380° and Ducati calls it “Twin Pulse.” It should be like nothing else we have heard to date, since the two cylinders of each Vee fire with a 90-degree interval, and the two Vees are separated by a “silence” 200-degrees long. Like in the MotoGP racer, the engine turns backward, to contribute to a more agile steering response by countering the rotational inertial of the wheels. The whole V-4 is rotated 42 degrees rearward in order to achieve a longitudinal compactness that was not possible with the Panigale V-twin. This will be a major virtue in a bike that will be able to mix a compact wheelbase with perfectly balanced weight distribution, two factors that were hard to put together with the traditional Ducati V-twins.

The compactness of the new V-4 engine is reflected in its dry weight of 143 pounds, less than five pounds heavier than the Panigale 1299. This is due in part to the rods that are only 101.8mm center to center, slightly less than double the stroke. The engine breathes through oval throttle bodies with an area corresponding to a 52mm round unit and the velocity stacks have variable geometry and inhale from a 12.8-liter airbox located atop the Vee. The inlet valves have a diameter of 34mm while the exhaust valves are 27.5mm. They must be set at a rather narrow angle, since the compression ratio is 14.0:1 for a supreme thermodynamic efficiency.

All this engineering delivers a claimed 210 peak hp at 13,000 rpm and 88.5 pound-feet peak torque constant from 8,750 to 12,250 rpm. This is a very impressive torque curve that should provide supreme flexibility and riding pleasure. Lubrication is by dry sump with four pumps, one for high pressure delivery and three for scavenging, to extract fumes from the crankcase and reduce pumping losses. This is the same that the great Keith Duckworth did in his legendary Ford DFV F1 V-8.

The new Ducati V-4 Desmosedici Stradale engine will act as a stressed member of the frame, in the best Ducati tradition, but that we will have to wait and see at the upcoming EICMA Show in November.