We’ve already told you about BMW’s new R1250 flat twin platform, about to debut at Intermot (we think). Now, we’ve got a look at the “Shiftcam” technology featured in the engine’s top end.
This video, unearthed by Motorcular.com, shows BMW’s approach variable valve timing technology, using cams with multiple lobes (in this case, two lobes) and a shiftgate at the end; under light throttle openings (“part load”), the lobe optimized for that scenario engages the valvetrain. Under heavy throttle openings (“full load”) the shiftgate moves the cam over, so the more aggressively profiled lobe (with more duration and higher lift) engages the valvetrain.
There should be multiple benefits to this design. Presumably, it makes for more efficient fuel usage, better throttle response at all positions, and lower emissions.
Along with the engine’s internals, the video also shows the new R1250GS as a complete bike, and tips the horsepower and torque ratings (136 hp, 105 lb-ft of torque, up from 125 bhp and 92 lb-ft).
I hope its backwards compatible to my ’98 R1100RT.