The Superquadro

October 10, 2011 by

Meet Superquadro, the most powerful twin-cylinder production engine on the planet !

Ducati has yet again set a new absolute production twin-cylinder milestone of 195hp @ 10,750rpm and 98.1 lb-ft (13.5kgm) @ 9,000rpm, the power delivery is customizable with several Riding Modes that deliver the power appropriate to your riding style .

The engine might have the same looks of the 1098 and the Desmo driven valves, but it houses a completely different technology…so S1000RR here comes البنغالي .

I’ll leave you with Ducati technical words on the Superquadro :

“ The new bore and stroke ratio of 1.84:1 effectively increases rpm with the ultra-short stroke of the crankshaft and increases the cylinder area to enable increased valves diameters. Inlet valves have increased from 43.5 to 46.8mm and exhaust valves from 34.5 to 38.2mm.

With such large inlet valves operating at higher rpm, the intense inertial forces have been controlled by using titanium instead of steel, a solution only previously used on full “R” models. The new valves are actuated by racing-derived rocker arms, ‘super-finished’ for reduced friction and fatigue and then coated in polymeric-like carbon (PLC), a process originally developed for the aerospace industry.

The race-derived Superquadro pistons have a distinctive double-ribbed undercrown to achieve high strength and reduced friction by using minimal piston wall surface area. Using technology developed by Ducati Corse, the design enables reliable operation of the 112mm diameter pistons when performing at high rpm.

The improved volumetric efficiency of the increased inlet valve diameters is further capitalised on by increasing the oval throttle body dimensions from an equivalent diameter of 63.9 to a massive and high-flowing 67.5mm. The Ride-by-Wire throttle bodies feed air across twin injectors per cylinder, one positioned below the butterfly for enhanced flexibility and one above for outright power.

The cylinders, which remain at 90° to each other, have been rotated backwards around the crankcases by a further 6°, until the front cylinder is 21° from horizontal. This has enabled the engine to be positioned 32mm further forwards for improved front / rear weight distribution in addition to perfectly positioning the cylinder head attachment points for the 1199 Panigale’s monocoque frame.

The crankcases, which are vacuum die-cast using Vacural® technology to ensure optimal weight saving, consistent wall thickness and increased strength, also incorporate in their form the outer water-jacket of the “cylinder”, eliminating the jointing face that used to exist at the base of the cylinders. Instead, the Superquadro has separate nikasil-coated aluminium “wet-liners”, which are inserted into the tops of the crankcase apertures during initial assembly. This design enables secure fixing of the cylinder head directly to the crankcase, improved sealing and enhanced heat dissipation from the thin cylinder-liners directly into the surrounding coolant.

The primary-drive casing, clutch casing and outer cover, sump and cam covers are all cast in magnesium alloy, ensuring a lightweight engine despite its increased strength as an integral part of the chassis.

In addition to cylinder position, the crankcases now use shell main bearings for the crankshaft, previously only used by Ducati on the Desmosedici RR engine. Removing the roller bearings has enabled an increase in diameter of the crank journals for enhanced rigidity and an increase the crankcase section around the main bearing area for improved strength in line with the Superquadro’s extreme power output. The shell bearings are force-fed oil from internal drillings within the main bearing pillars to keep the new crankshaft well lubricated and is quickly scavenged back into the sump with the introduction of a new Ducati feature, a highly efficient MotoGP-style vacuum pump.

The pump is driven by the main oil pump shaft and effectively maintains constant vacuum in the crankcase area below the pistons, reducing atmospheric resistance during the down-stroke of the piston and controlling the internal “breathing” of the engine.

With such enhanced “breathing”, the challenge for the Superquadro’s Design Engineers was to program performance-optimised fuel mapping for a smoother cycle-to-cycle engine operation, without compromising emissions. To achieve this, Ducati introduced a secondary air system that completes the oxidisation of unburned hydrocarbons and effectively reduces HC and CO levels. The system is activated when the engine ECU recognises specific conditions in the engine’s operation via the lambda and throttle opening sensors. It then opens a valve enabling a flow of clean air from the main airbox to a reed valve situated in each cylinder head, which enables one-way flow into an air gallery exiting into the exhaust port close to the exhaust valve. Entering the hottest point of the exhaust gasses, the fresh charge of air enhances the burn environment, eliminating any unburned fuel that escapes during the exhaust cycle under certain conditions.

With such an extreme engine, never before has Ducati’s unique Desmodromic system been so vitally important. With the high engine speeds at which the Superquadro operates combined with such large valves, it would be impossible for the valve’s rocker-arm to follow the steep closure profile of the cam lobe using normal valve closure springs.

The Desmo system actuates valve closure mechanically with the same method and accuracy as it opens, enabling steep cam profiles, radical cam timings, large valves and high operating speeds. This system is used on every single Ducati motorcycle and constantly proven on Ducati Corse’s World Superbikes and Desmosedici MotoGP bikes.

The conventional bush-type chain runs from the crankshaft to the cylinder head where a single sprocket positioned between inlet and exhaust camshafts, is attached back-to-back to a gear wheel mounted on its own short, dedicated shaft. The attached gear meshes directly with gears on the ends of both the inlet and exhaust camshafts, which are also designed with +/- position adjustment for ultra-precise cam-timing. The cam chain, therefore, provides highly efficient point-to-point drive route and, tensioned automatically, provides continuous reliability and further reducing the cost of routine maintenance.

On the end of each exhaust cam drive gear is a centrifugal flyweight which retracts at speeds below tick-over to rotate a “protrusion” from the concentric section of the cam, thus creating just enough inlet valve lift to act as a de-compressor. This ingenious device enables the Superquadro engine to be started easily without using a larger battery and starter motor, which has reduced overall vehicle weight by approximately 3.3kg (7.3lb). When the engine starts and the camshafts begin to rotate at tick-over speed, the centrifugal flyweight flicks out, retracting the “protrusion” back into the cam and allowing complete valve closure for full compression. This innovative feature further underlines the lengths to which designers and engineers have worked together in the single-minded pursuit of weight-saving.

Ducati’s engineers also capitalised on the opportunity of the “blank canvas” project to increase dimension between the centres of the six-speed gearbox shafts, enabling larger diameter, stronger gears to transmit the enhanced power output.

New for a top-of-the-range Ducati Superbike is a “wet”, oil-bath clutch. Based very closely on the design of the Multistrada and Diavel components, the clutch assembly features a “slipper” function and a progressive self-servo mechanism that compresses the friction plates when under drive from the engine. While enhancing frictional efficiency, this also results in a rider-friendly light clutch lever “feel” at the handlebar. Conversely, when the drive force is reversed (over-run), the mechanism reduces pressure on the friction plates, enabling a true racing “slipper” action, reducing the destabilizing effect of the rear-end under aggressive down-shifting and provide a much smoother feeling when closing the throttle or down-shifting under normal riding conditions.”