one
BMW Motorsport, a combat engine with the S63B44 index, grew out of a civilian 4.4-liter V8 with two turbochargers (designation N63). In the usual version, it develops 407 hp, when installed on X5M and X6M crossovers, its power was inflated to 555 “horses”, and on the M5 sedan it gives out five more forces. For a modest increase lies a considerable amount of change. Engineers increased the compression ratio from 9.3 to 10.0, revised the architecture of the intake channels and the exhaust tract. The motor of the sedan was equipped with the third-generation Velvtronic proprietary system, which changes the valve lift height, which is deprived of both the base engine and the crossover unit with index M.
The border of the already vast area of torque moved up 100 rpm: 680 Nm are available in the range from 1500 to 5750 rpm. The speed limiter operates at 7200, which is 200 rpm more than the X5M and X6M. Of course, the control electronics of not only the engine, but also the transmission are reconfigured.
The location of the catalytic converters in the collapse of the cylinder block is a shot at two birds with one stone. It is compact and ecology. After all, proximity to the combustion chambers is the key to quick warming up to operating temperature and minimal emissions after start-up.
2
The design of the exhaust manifold is protected by patent. Four pipes in pairs connect the cylinders of the opposite rows of the “eight”. Moreover, the exhaust gases from the extreme cylinders spin small turbine wheels, and from the central ones large ones. Thus, the flows moving in antiphase do not collide in one pipe in front of the turbine, due to which a faster and more uniform spinning of the supercharger is achieved.
3
The engine is equipped with two Twin Scroll turbochargers, and each turbine housing is composed of two coils of different diameters. This design allows you to increase the working range of boost: at low speeds, the exhaust gases quickly spin up a large wheel (quick response to the accelerator pedal). At high, the necessary compressor rotation speed, calculated on the required boost pressure (up to 1.5 atm), is provided by a small snail - in order to develop more power. All components of the turbocharger for the sake of compactness were placed between the cylinder blocks of the V8 engine with a 90º camber angle.
four
A sophisticated system of ten modules, responsible for cooling all components, monitors the operating temperature of the cylinder block and mounted units of the engine, engine and transmission oils, turbochargers and compressible air. After the engine stops, two electric pumps drive the fluid along the cooling circuits, evenly lowering the temperature and avoiding harmful local overheating.
five
Despite the design with a "wet" sump, the lubrication system is not afraid of significant lateral overloads with active driving. Vertical partitions on the bottom of the sump do not allow to quickly flow over the entire volume of oil. Moreover, an additional pump was installed for the uninterrupted lubrication of the 8-cylinder “heart”. And the shape of the drain channels was calculated so that the oil that left the working area was returned to the crankcase as quickly as possible.
6
The combination of high power and moderate gas mileage distinguishes the system of high-precision fuel injection into the combustion chamber. For effective ignition of the mixture, the nozzle is located as close to the spark plug as possible, and its tilt angle is calculated for optimal mixture formation. Gasoline is supplied several times per stroke at a pressure of 200 bar.
