BMW unveils new engine family with 1.5 L BMW TwinPower Turbo engine
15 September 2012
BMW announced a completely new EfficientDynamics engine family—including 3, 4 and 6 cylinder, in-line gasoline and diesel models—that utilize the BMW TwinPower Turbo technology and that have been designed to provide a high level of commonality across the platforms. The first member of this new engine family is a 3 cylinder TwinPower Turbo gasoline unit.
The term “TwinPower” designates the combination of variable load control and the latest fuel injection technology. The intelligent, control technology modules include the (double) Vanos infinitely variable camshaft control system, the VALVETRONIC variable valve timing system and the variable turbine geometry of the diesel turbochargers.
These technologies are complemented by the High Precision Injection direct fuel injection system for gasoline engines and the Common Rail direct injection system for diesel units. Turbocharging is an important element of this technology package. BMW TwinPower Turbo engines can be charged with a single turbocharger, dual turbochargers, a twin scroll turbocharger or with a triple turbo unit.
An essential feature of the gasoline engines is the VALVETRONIC throttle-free load control system. Unlike a conventional load control system using a throttle valve, VALVETRONIC responds to the driver’s power requirement by varying the valve lift, which results in systemic efficiency gains.
The first engine of the new range unveiled by BMW is the 1.5 liter TwinPower Turbo power unit. The 1.5-liter BMW TwinPower Turbo engine features “significantly reduced fuel consumption” by virtue of its low internal friction. Due to the long ignition intervals, the charge cycle can be particularly well adapted to suit the needs of the driver, providing a high low end torque and a rapid response.
In terms of vibration characteristics, the 3-cylinder engine is free of first and second order inertial forces, while the roll torque is eliminated by the use of a balance shaft. With its torsional vibration damper, which works on the principle of a centrifugal pendulum, the engine behaves well even at low rpm, said BMW.
The new family of engines shares a common design principle for all of the in-line units. The basic engine is made up of cylinder modules with capacities of 500 cc each. Consequently the new 3-cylinder engine has a capacity of 1.5 liters, the four-cylinder unit is 2.0 liters and the six-cylinder is 3.0 liters. The power developed in each cylinder is between 30 and 55 kW (40 and 74 hp) with 60 - 80 N·m for the gasoline engine, while the diesel develops between 20 and 45 kW (26 and 60 hp) with 75 - 110 N·m.
The structural similarities between the gasoline and diesel engines include the distance between cylinders, the aluminum crankcase, the balance shaft design, the arrangement of the timing chain, the layout of the cylinder head bolts and the high-quality coating on the cylinder bore surfaces. The number of identical parts used in engines powered by the same type of fuel climbs to 60%, while the level of structural similarities between gasoline and diesel engines is around 40%.
Additional benefits are provided by standardized interfaces. In addition to the identical engine mounting points, these are primarily the interfaces to the cooling circuit, the intake and exhaust manifolds and the heating and air conditioning systems. Compared to current models, the number of possible combinations in these areas has decreased by about half.
All of the power units also have the same “cold” intake and “hot” exhaust sides, enabling both longitudinal and transverse mounting in future BMW and MINI models.
For the first time, gasoline and diesel engines belonging to this new range can be manufactured together, at the same time, in the engine production facility, which will allow a more flexible response to even short-term fluctuations in demand or new market developments.
Source: BMW