 |
Latest Specs |
 |
|
|
|
|
Popular |
|
|
|
|
|
|
M6 Cabrio - e64 (2006 - ...) |
|
|
|
|
Page 6 of 8 Effortless Muscle
Formula 1 technology for the road.
The V10 power unit developed by BMW M GmbH is one of the most
fascinating engines ever offered in a four-seater production convertible.
And this is no surprise, considering that this supreme engine is based on
BMW’s world-famous ten-cylinder Formula 1 power unit acknowledged
as the most powerful engine in the highest category of motorsport until the
change in rules and regulations in 2006.
The V10 proudly boasted in the BMW M6 Convertible shares not only the
number of cylinders and their configuration, but also the high-speed engine
concept with this supreme F1 power unit. The result is enormous power
and pulling force from high engine speeds, a quality characteristic of all highperformance
naturally aspirated engines from BMW M GmbH. The facts
and figures alone are more than impressive, ten cylinders, five litres engine
capacity, 373 kW/507 hp, maximum torque of 520 Newton-metres
or 383 lb-ft, and top engine speed of 8,250 rpm telling a clear story.
As impressive as all this is on paper, the qualities of the engine are even more
thrilling on the road: Just merely touching the gas pedal, the driver
will enjoy all the qualities of a typical high-performance sports engine in the
BMW M6 Convertible reminiscent even in its sound of the marque’s former
Formula 1 power unit.
Formula 1 technology for the road.
BMW M has always regarded the high speed engine concept – more power from
higher engine speeds – as the best and most appropriate strategy. And truly
reflecting this philosophy, the V10 power unit reaches engine speeds formerly
regarded as quite impossible in a production engine due to the enormous
forces acting on the materials and components alone: At 8, 000 rpm, each of the
ten pistons covers approximately 20 metres or 66 feet a second – almost twice
as much as the pistons in a Formula 1 power unit. But while long-lasting driving
qualities are a relative factor in motorsport, an M power unit will last the long
life of a car built for many years of driving pleasure – in every climate, under all
driving conditions, and with every style of motoring.
The high-speed engine concept offers decisive benefits: First, output per litre
of 101 horsepower generally experienced only in motorsport, with the engine’s
maximum power of 507 hp or 373 kW coming from relatively small engine
capacity of 4,999 cc. Second, the compact design and dimensions of the
engine serve to reduce the overall weight of this high-performance power unit
to just 240 kg or 529 lb.
Contrary to similarly powerful engines based on a different concept,
the M high-speed concept allows use of a lighter powertrain and shorter
transmission ratios, reducing the weight and masses to be accelerated
in the car. This again directly benefits the driving dynamics of the
BMW M6 Convertible, particularly the car’s acceleration resulting from
superior torque at high engine speeds and an appropriate overall transmission
ratio. Outperforming other concepts, the fast-revving V10 power unit
allows optimum gearbox and final drive transmission ratios, conveying
impressive power and performance to the drive wheels at all times.
Developing peak torque of 520 Newton-metres or 383 lb-ft at 6,100 rpm,
the V10 guarantees supreme power at all times, especially as 450 Newtonmetres
or 332 lb-ft comes from just 3,500 rpm and 80 per cent of the
engine’s maximum torque is maintained consistently throughout a wide speed
range of 5,500 rpm.
As unusual as this is for a sports engine, the driver enjoys the full benefit at all
times: The BMW M6 Convertible offers the very best in sporting performance
and in relaxed cruising on a country road. Acceleration from 0–100 km/h, for
example, comes in just 4.8 seconds and the BMW M6 Convertible completes
the standing-start kilometre in 22.9 seconds. Acceleration from 80–120 km/h
or 50–75 mph in fourth gear, in turn, takes just 4.7 seconds as yet further proof
of the car’s supreme performance.
Ten cylinders – the ideal concept for sports motoring.
Looking at the engine’s dimensions and the number of components, ten
cylinders are the optimum engine concept. A further advantage is that
capacity of 500 cubic centimetres in each cylinder is ideal for a highly efficient
combustion process, the M power unit combining two rows of five
cylinders each in a 90° V-angle and with 17 millimetres or 0.67´´ cylinder bank
displacement to form an extremely compact engine in ideal configuration.
The 90° angle was chosen on account of its superior mass balance for
minimum vibration and maximum comfort, offering the ideal combination of
smoothness and component strength.
With high engine speeds, combustion pressures and temperatures subjecting
the crankcase to extreme loads, the engineers at BMW M have opted for
an exceptionally compact and torsionally stiff bedplate structure. Conceived for
superior stiffness and finely balanced, the crankshaft is made of forged,
high-strength steel, runs in six bearings, and weighs just 21.8 kilos or 48.1 lb.
The weight-optimised box pistons, in turn, are cast out of a high temperatureresistant
aluminium alloy and come with special iron surface coating.
Piston weight is just 481.7 grams including the piston pins and rings. And the
weight of the trapezoidal conrods made of high-strength steel has also
been optimised to the last gram.
The single-piece aluminium cylinder heads boast four valves per cylinder,
again typical of a BMW engine, and are operated by spherical cup tappets
featuring hydraulic valve play compensation. Measuring 5 millimetres or
0.20´´ in diameter, the intake valves are particularly slender and therefore hardly
impair flow conditions in the intake manifold.
The crossflow cooling concept minimises any loss of pressure in the cooling
system, maintains consistent temperature distribution in the cylinder head,
and reduces peak temperatures at all critical points. To ensure an optimum
flow of coolant around each cylinder, the coolant flows from the crankcase via
the outlet side through the cylinder head and across the collector rail on the
intake side to the thermostat and the radiator.
Reliable supply of oil even in extremely fast bends.
Clearly, the V10 power unit in the BMW M6 Convertible guarantees
exceptional performance at all times. And since this also means truly
outstanding straight-ahead and lateral acceleration, the lubricant in the engine
is sometimes forced so hard into the outer row of cylinders in a bend that
as a result there might even be a shortage of oil in the sump. Starting at lateral
acceleration of approximately 0.6 g, therefore, oil is drawn from the
outer cylinder head in a bend and pumped back to the main oil sump.
Since extreme braking manoeuvres might also interrupt the reflow of oil, the
quasi-dry sump lubrication system with one oil reservoir up front and one
behind the front axle subframe provides the desired counter-effect, a reflow
pump extracting oil from the front oil sump and pumping it to the rear sump
wherever required.
|
|
|
|
|
Login |
|
|
|
|
|
Poll |
|
|
|
|
|
The database can be found here |
|
Latest Pictures |
|
|
files: 4764
albums: 247 (latest)
categories: 65
5 latest additions:
|
|
