The twelve-cylinder is the king of the engine world and the true heart of the Lamborghini brand. The very first model created by Feruccio Lamborghini, the 350 GT, made its appearance in 1964 featuring a twelve-cylinder engine that was incredibly innovative for its day. 3.5 liter displacement and 320 hp were the vital statistics back then – they formed the basis for ongoing increases and further development over the decades that followed. Miura, Espada, Countach, Diablo and, finally, Murciélago are just a few of the super sports cars born in Sant’Agata. All of them were, and will continue to be, driven by V12 engines – and all have long since risen to the status of automotive legend.

Now the next milestone in this glorious history appears – engineers in the Lamborghini R&D Department have developed a completely new high-performance power unit. That it would be another twelve-cylinder was never in doubt - and not only because of the special magic conjured up by the number twelve. The only real choice for Lamborghini is a high-revving naturally aspirated engine – the deeply reflexive and exceptionally powerful reaction of the automobile to the tiniest movement of the driver’s right foot is, of course, a key part of the whole fascination inspired by a super sports car. Ten cylinders are ideal in the displacement class around the five liter mark, as evidenced by the highly acclaimed Gallardo engine. For the 6.5 liter displacement targeted in this case, the perfect number is twelve. A lower number of cylinders would result in larger and heavier pistons and con-rods, which would have a negative impact on the engine’s high-revving characteristics.

Starting with a clean sheet of paper

The specification for the development of the new twelve-cylinder, known internally as the L539, was written quickly – yet was highly demanding in its formulation. Naturally, it had to deliver more power and torque than its predecessor in the Murciélago, but it should also be smaller and lighter and enable a lower center of gravity. At the end of the day, low weight is just as important to the performance of a super sports car as high power output. Fuel consumption and gas emissions should also be reduced significantly.

So the R&D team started with a clean sheet of paper – metaphorically speaking, of course. Design and development in Sant’Agata is conducted using state-of-the-art systems and equipment. The outcome is a V12 with a classic cylinder bank angle of 60 degrees, and thus an amazingly compact power package – the power unit measures only 665 millimeters from top to bottom, including the intake system. Its width, including the exhaust manifold, is only 848 millimeters, while its length is a mere 784 millimeters. Its weight of 235 kilograms is also respectably low – each kilogram of engine weight corresponds to 3.0 HP maximum output.

Optimized for high revving and low weight

The crankcase on the new power plant is made from an aluminum-silicon alloy and has an open-deck construction with steel cylinder liners. Displacement is 6,498 cm3 and cylinder spacing 103.5 millimeters, while bore diameter measures 95 millimeters and stroke 76.4 millimeters. The short-stroke layout is especially good for high-revving characteristics and for low internal friction. Particular attention was also paid to the bearings for the forged and nitride-hardened crankshaft, which weighs in at 24.6 kilograms.

The two four-valve cylinder heads are likewise made from sand-cast aluminum-silicon alloy, each weighing a very light 21 kilograms. The twelve pistons and con-rods are, respectively, in forged alloy and steel. The maximum piston speed at 8,250 rpm is only 21 meters per second, which is considerably less than for the Murciélago’s previous power unit. The combustion chambers were carefully engineered to achieve optimum tumble and combustion of the fuel/air mixture. At 11.8:1, the compression ratio is extremely high. Inlet and outlet valve timing is electronically controlled.

Sophisticated thermal management, optimized oil circulation

The thermal management of this high-performance power unit was perfected with extensive detail engineering. Two switchable water circuits in the engine ensure very rapid warm-up, which minimizes friction and quickly brings the catalytic converters up to operating temperature, thus benefiting fuel consumption and emissions. The external water coolers are switched into the circuit only as required.

Absolute engine health, even under extreme racetrack conditions with high lateral acceleration, is guaranteed by oil circulation using a dry sump system. A total of eight scavenger pumps suck oil out of the lower bedplate fastened to the crankcase. Pressure and scavenging losses are thus reduced by around 50 percent. A high-pressure oil pump maintains lubrication, while an oil/water cooler and an oil/air radiator constantly keep temperatures within range even under extremely high load. A further benefit of this form of dry sump lubrication is the very low mounting position of the engine within the sports car. The new engine is mounted 60 millimeters lower than the V12 in the Murciélago – with the associated benefits in respect of center of gravity and lateral dynamics.

From the outside, the V12 is dominated by its intake system – which incorporates four individual throttle valves. Life inside the black housing is also extremely complex – the optimum intake path for any given load and engine speed is facilitated by two flaps, several channels and one bypass. The payback is an extremely well-rounded torque curve and refined pulling power throughout the rev range.

Mighty orchestra for twelve voices

The exhaust system, too, was afforded the undivided attention of Lamborghini’s engineers – the lowest possible gas emissions was just as important a target as the unmistakable, spine-tingling Lamborghini sound. The hydro-formed and thermally insulated three-into-one system incorporates four pre-catalytic converters close to the engine and two main catalytic converters shortly before the muffler. The casing incorporates two separate mufflers – one low-volume, one high-volume. Regulated by valves controlled via the engine management, they handle all the elements of the big twelve-cylinder symphony – from a moderate rumble when rolling through the city at low revs to the screaming crescendo of maxed-out gear shifts.

Electronics devised entirely by Lamborghini

Another highlight is the electronic engine management, which was developed in its entirety by engineers at Lamborghini. The system consists of the main ECU, a secondary “smart actuators” and two additional black boxes that function as “smart sensors”. Because speed is everything for an engine like this, some ECU control and connection functions are handled by the smart actuators, making the ECU faster. The two smart sensors are constantly monitoring combustion in real time – each ignition in every cylinder. The spark plugs – each is powered by an individual ignition coil – function as “sensors”; the two auxiliary control units monitor the power signal after every ignition and can immediately identify irregularities in the combustion process through ionization phenomena. This data is used to continually optimize engine management, benefiting both performance and fuel consumption.

High performance in every dimension

All these technical highlights come together to create a high-performance power unit like no other. The maximum output of 515 kW (700 hp) at 8,250 rpm is an impressive statement in itself. The maximum torque is 690 Newton meters and is available at 5,500 r/min. The extremely generous torque curve, meaty pulling power in every situation, extremely reflexive responses and, not least, the finely modulated but always highly emotional acoustics make the L539 a stunning power unit for a super sports car of the highest order. And not only was the L539 developed entirely in-house at Lamborghini, it is also built from start to finish at company headquarters in Sant’Agata Bolognese. Highly qualified specialists assemble the engines by hand, with every single unit undergoing an extensive final testing and detailed calibration program on an engine test bed.

The new Lamborghini ISR transmission (ISR: Independent Shifting Rods) - Innovative servo-actuated mechanical gearbox for maximum performance

However, it is not the engine alone that defines the character and driving characteristics of a super sports car. Another key element is the transmission. The demands are clear – the ratios must be perfectly arrayed and enable optimum power delivery from the engine. For maximum vehicle performance, shift times should be less than the blink of an eye. Operation must be clear and straightforward, via two ergonomic shift paddles behind the steering wheel. The characteristics of the transmission must be in line with the wishes of the driver at any given point – from smooth city cruising through to tough action on the racetrack. And, not least, Lamborghini customers expect an emotional shift feeling that ensures the sports car’s reactions can always be felt and understood. Thus, the development objective was clearly formulated in this respect, too – create the world’s most emotional gear shift.

For all these reasons, the engineers in the R&D Department opted for a robotized gearbox as the “companion” of the new V12 power unit – however, in a very special iteration: the Lamborghini ISR transmission. This robotized gearbox combines extremely fast shift times, almost 50% less than dual-clutch transmission with the benefits of a manual transmission in terms of weight and compact dimensions – both always critical for super sports cars

Unique engineering for supersportscars

The new unit is laid out as a two-shaft transmission with seven forward gears and one reverse. For especially high durability, the synchronizing rings are made from carbon-fiber – a material with which Lamborghini has enormous experience. The short shift times are facilitated by the special design of the transmission, known as ISR – Independent Shifting Rod.

To summarize the principle – in a conventional manual gearbox, be it automated or fully manual, the gear wheels for, say, second and third gears are located side by side. When the driver wants to shift gear, the shifting sleeve with synchronizer unit is moved along the shifting rod from second gear through neutral to third gear. This requires twice the distance and twice the time – second gear has to be disengaged before third gear can be engaged.

Short distances, fast shift times

This process is significantly shortened in the Lamborghini ISR transmission – the gear wheels from the second and third gears are separate from each other and the shifting sleeves are actuated by independent shifting rods. Now the shifting process can run virtually in parallel – while one shifting rod is disengaging one gear, the second shifting rod can already engage the next gear. Because these movements partially overlap and the mechanical distances are considerably shorter, this facilitates a significant saving in shift time. Overall, the Lamborghini ISR transmission shifts around 40 percent faster than the e.gear transmission in the Gallardo. And that is already one of the world’s fastest automated manual gearboxes.

Compact construction, low weight

The new transmission has four of these independent shifting rods, with sensors constantly monitoring their exact positions. They are operated via hydraulic actuators, with an extremely high system pressure of 60 bar ensuring the necessary operating speed. The system incorporates a total of seven hydraulic valves, with pressure supplied by an electric pump. The double-plate clutch is also hydraulically actuated. All system components are contained within one casing. The total weight of the transmission is only 70 kilograms – a distinct advantage, especially compared with the significantly heavier dual-clutch transmissions from the same category

Three operating modes for all situations

Lamborghini drivers can choose between three operating modes – the Strada mode offers highly comfort-oriented shifting, with fully-automatic also an option. The Sport mode has a dynamic set-up in terms of shifting points and times, while the Corsa mode delivers the maximum shift strategy for race track driving. This mode also includes Launch Control, the automatic function for maximum acceleration from a standing start.

With the Lamborghini ISR transmission, engineers working under the sign of the bull have devised an ingenious mate for the new twelve-cylinder power unit. Their work has created an overall powertrain that is absolutely unique in the world of super sports cars.

Integrated electronic control system

The excellent performances are possible only by a fast communication architecture through the several powertrain ECU’s and considering the powertrain as ONE-system (un unico sistema) in the car.

The fully electronic controlled coupling device for the front wheels (the ‘old’ viscous coupling) is another key point of the powertrain: it is able to continuously distribute the right torque to the front wheels for always attaining the best performance aspired to by the driver. The torque distribution to the front wheels can vary continuously from 0% to 60% of the total torque available.