Conical Manifold

Conical Manifold

Bmw 760Li (2010)

Last year, the 7-Series went from being one of our least-favorite luxury sedans to one of our most coveted. Mostly it's because of the styling. BMW had a mission to make the 7er look different-and that 2002-2008 7-Series took it to extremes. The greenhouse grew tall, the fenders drooped, and the trunklid sprouted a vestigial double deck. Now, the newest 7-Series looks much more relaxed and much happier. The glass areas are slimmer, the shoulders are tailored just right, and the decklid's been smoothed over, with the trunk and taillights more tightly integrated. The Hofmeister kink, at the junction of its D-pillar and rear doors, is sublimely sporty. Even the grille looks pleased-it splits into a wider grin, and the front aero dams dip low for a grounded look. The long-wheelbase versions don't tip the shape out of balance at all, with a small stretch in glass areas in the rear doors.

original article  read full article

BMW 760Li

BMW 760Li

Optimised combustion and maximum efficiency ensured by High Precision Injection.

BMW High Precision Injection is a second-generation direct injection technology serving to optimise the combustion process and use the energy contained in the fuel with maximum efficiency. Piezo-injectors positioned in the middle of the cylinder head allow particularly precise dosage of the fuel injected into the combustion chambers.

In combination with TwinPower Turbo Technology, High Precision Injection is featured in all gasoline engines in the BMW 7-Series. And now, in the new V12 power unit, this technology ensures particularly efficient and clean combustion as the starting point for a level of fuel economy and emission management quite unparalleled in this class of performance.

Opening up to the outside, the piezo-injectors are positioned in the cylinder head between the valves and, as a result, directly next to the spark plugs. They are supplied with fuel through stainless-steel pipes, fuel then being injected into the combustion chambers in finely atomised form at a pressure of up to 200 bar. This system pressure is generated by single-plunge fuel pumps on each row of cylinders and is maintained reliably at all times by short pipes and fuel travel.

The fuel injected in this process spreads out in conical form, thus burning in a particularly smooth and clean process. This, in turn, has a positive effect on engine emissions and sound, the cooling effect of the fuel/air mixture provided by direct fuel injection helping in addition to achieve a higher compression ratio than on a turbocharged engine with manifold injection. The bottom line, therefore, is an even higher degree of engine efficiency generating more power on less fuel.

In their configuration and structure, the cylinder heads largely follow the particular position of the injectors and spark plugs as well as the combustion process provided by High Precision Injection. Short combustion phases optimised for maximum efficiency build up a high level of pressure and temperature requiring optimised cylinder head geometry and an effective flow of coolant. The cylinder head components cast in a gravity process stand out in particular through their very high level of stiffness, while the cylinder head covers are made of aluminium and come with rubber profile seals.

Double-VANOS and volume flow-controlled oil pump for maximum efficiency.

Again in typical BMW style, the new twelve-cylinder comes with double-VANOS for infinite adjustment of camshaft control timing. This ensures part load running conditions with a high level of residual gas and reduced throttle loss for maximum fuel efficiency.

A further advantage of double-VANOS is its support in giving the engine a particularly direct response. Joined in a thermal process, the camshafts come with forged cams, additional triple cams on the intake side serving to drive the high-pressure fuel pumps. The valves on the exhaust side, in turn, are filled with sodium for optimum cooling and come with chrome-plated shafts.

The supply of oil to the new twelve-cylinder has also been optimised, the volume flow-controlled oil pump operating on individual demand with maximum efficiency: The six-chamber pendulum-slide pump delivers only as much oil as the engine requires at any given point in time under specific driving conditions.

An oil level sensor is integrated in the oil sump made of pressure-cast aluminium. And instead of a manual oil dipstick, an oil level indicator in the instrument cluster also operating while driving informs the driver of the oil level whenever required.

The new twelve-cylinder models in the BMW 7-Series again feature a wide range of technologies for minimum fuel consumption and emissions based on BMW's strategy of EfficientDynamics. These include Brake Energy Regeneration, electric coolant pumps operating on demand, and the volume flow-controlled oil pump further optimising the balance of load performance and fuel consumption.

With an increase in engine output versus the former models by 22 and an increase in maximum torque by 25 per cent, the average fuel consumption determined in the EU test cycle has been reduced to 12.9) litres/100 kilometres. The emission rating of the BMW 760i is 299) grams per kilometre.

The engine coolant system on the new twelve-cylinder excels through consistent integration of all pipes in the crankcase, optimised cross-sections and the surface structure ensuring a maximum heat exchanger function helping to warm up the engine far more quickly than before on the former power unit.

The arrangement of the coolant inlet immediately next to the main inlet duct for supplying oil serves in addition to connect the two media in thermal terms, again helping to warm up engine oil and maintain the ideal temperature at all times.

The flow of coolant is separated on the two rows of cylinders, in each case running diagonally from the rear outside to the front inside. And last but not least, the arrangement of the outlets again helps to consistently spread out and maintain the temperature level over a wide range of engine speed.

BMW's outstanding competence in twelve-cylinder technology: a long tradition of supreme performance.

This is the fourth time that a twelve-cylinder power unit marks the top end of the engine portfolio featured in the BMW 7-Series. And indeed, every new generation has further reinforced BMW's position as the leading manufacturer of luxury performance saloons. A BMW 7-Series with a twelve-cylinder power unit stands for exclusivity, supremacy and, not least, genuine innovation, the top-of-the-range engines providing the highest standard also on account of the maximum demands they are expected to meet right from the start in the development process.

BMW's outstanding competence in the development and production of twelve-cylinder power units is based on a long tradition extending all the way back to the year 1925 when the Company for the first time hit the headlines by building an aircraft engine with twelve cylinders. Back then BMW's V12 developed maximum output of 750 hp, with two BMW twelve-cylinders powering the Dornier Wal seaplane just five years later in its record flight across the Atlantic.

In the second half of the 20th century BMW became the pioneer in introducing the twelve-cylinder in the most outstanding luxury cars. The BMW 750i launched in 1987, for example, was the first German twelve-cylinder saloon after the war. In the years to follow a long story of success in motorsport likewise contributed to the exceptional reputation of BMW's twelve-cylinders. The BMW V12 LMR, for example, dominated the racing scene right from the start in its very first race in 1999, the 12 Hours of Sebring, and in the same season clinched overall victory in the 24 Hours of Le Mans.

World debut: eight-speed automatic transmission in the new BMW 760i and the new BMW 760Li.

The unique qualities of the new V12 power unit with TwinPower Turbo Technology and High Precision Injection are combined in the new BMW 760i and the new BMW 760Li with an equally innovative concept for the transmission of power: the newly developed eight-speed automatic transmission making its world debut in a BMW production car. Ideally tailored to the power and performance characteristics of the twelve-cylinder power unit, the eight-speed automatic transmission combines supreme gearshift comfort, sportiness and efficiency at a level never achieved before.

The new eight-speed automatic transmission excels through the innovative configuration of gears and gearsets allowing the use of additional gears and a larger range of gear increments than on the former six-speed automatic transmission, without any negative effects on the size of the transmission, its weight, and the inner efficiency of the system.

The eight forward gears and the reverse gear all incorporate four simple gearsets and five gearshift elements. The innovative arrangement of these components seen for the first time on an eight-speed automatic transmission ensures that only two clutches are open in each gear at any given point in time, significantly reducing frictional losses under all driving conditions to an absolute minimum.

Over and above the wider range of gear increments and the high degree of internal efficiency, this is a further factor contributing to the outstanding overall efficiency of the new transmission system. So again, the intelligent concept of this new eight-speed automatic transmission harmonises perfectly with the BMW EfficientDynamics development strategy.

Introduction of the first eight-speed automatic transmission in the BMW 760i and the BMW 760Li marks the starting point to a generation change in the area of power transmission systems. The six-speed automatic transmissions currently featured in all BMW model series already set the standard in terms of shift comfort, reaction time, gearshift speed, and efficiency and, through their compact design and configuration as well as their universal use in various vehicle segments and power classes, already offer unparalleled all-round qualities. The first and foremost objective in developing the new generation of automatic transmissions, therefore, was to retain all the design features of the six-speed automatic transmission and add new potentials in terms of motoring comfort, performance and efficiency.

 

About the Author

motonica-p81