ENGINE / DRIVE
SIX CYLINDER INLINE ENGINE
For over seventy years, six cylinder inline engines have been representing fascinating engine technology made by BMW. Yet always in cars. The two unmistakable tourers BMW K 1600 GT and BMW K 1600 GTL are the first to be powered with an inline six cylinder. Like no other, this active riding heart represents perfect refinement, the majestic development of power and torque, high pulling power, an incomparable sound, and therefore pure emotion.
A new BMW development, this 1649 cc engine delivers 118 kW (160 hp) at about 7750 rpm and a max torque of about 175 Nm at about 5250 rpm. Over 70% of the maximum torque is available from just 1500 rpm. Both gentle cruising and sporty, majestic touring are therefore possible.
Together with its alternator, intake system, clutch, and gearbox, the inline six cylinder engine tips the scales at solely 102.6 kg. Thanks to its consistent lightweight design, e.g. in the form of hollow camshafts, it is the lightest six cylinder inline engine in series motorcycle production. And with its width of 555 mm, about 100 mm smaller than all six cylinder inline engines produced to date for series motorcycles, it is also the most compact.
The small installed width was achieved above all with a relatively long stroke for a slightly oversquare stroke/bore ratio of 67.5:72 mm (0.938) and very small distances between the cylinder axes of 77 mm. In addition, all of the electrical auxiliary units were installed behind the crankshaft in the space above the gearbox.
Like in the present BMW four cylinders, the cylinder bank is inclined to the front through 55°. This results in a low centre of gravity and a balanced distribution of weight. Also the integrated dry sump lubrication, replacing the conventional oil sump and reservoir, allows a deeper installed position. In addition, the inclination creates space for an intake system with optimal flow properties directly over the engine.
The efficient combustion, the low speed level, the high accelerator speeds, and the minimised friction all contribute in the six cylinder engine to an extremely high efficiency and therefore a low fuel consumption in line with the times. The engine also achieves top grades for its performance potential, on a level with a comparable four cylinder motorcycle.