I still remember that the last evolution from R 1 150gs to R 1200gs was that the cooling mode of the engine changed from gas-oil cooling to water cooling, and the biggest innovation of this change from R 1200gs to R 1250gs came from the power unit, which was called "by BMW" ?
In fact, for such a best-selling car, the sales volume has proved its strength, and any change, especially the change of power unit, is risky, but BMW is still full of confidence and once again brings a brand-new technical blessing to its flagship rally model, that is, variable valve timing technology. Although this technology has long been exhausted in the automobile field, it is rare in two-wheeled motorcycles. ?
Today, Bian Xiao will briefly introduce the variable valve timing system used by BMW in the new boxer engine. This system can be roughly summarized into three aspects. First, the task of "variable valve timing" is completed by two groups of "cams" with different heights on a camshaft (taking a cylinder as an example) (it can be clearly seen from the official map that the length of the upper intake valve camshaft is almost twice that of the lower exhaust valve camshaft)?
Secondly, the basis for this set of "variable valve timing" to switch between two different valve timing settings is the throttle opening, not the engine speed; Thirdly, the component that completes camshaft switching is not our usual mechanical or hydraulic structure, but a small motor placed inside the engine.