Harley Davidson with V-twin supercharger
Typically, motorcycle engines are supercharged for maximum performance. The very words supercharger, turbine, compressor conjure up something powerful, roaring and conquering everyone. Take the Kawasaki H2 family for example – the only production bikes to date equipped with a supercharger from the factory – their aggressive styling and the incredible speed they can pull off the stereotypes of supercharger super monsters.
However, in the automotive industry, different types of supercharging are used not only to improve the performance of engines, but also to improve their efficiency in terms of fuel combustion, and therefore to comply with more stringent environmental standards.
Yes, for a supercar, a supercharger is almost a mandatory attribute, but little keikars with a 0.7-liter engine are also often turbocharged from the factory.
Harley Davidson patent
In the motorcycle world there is an abundance of various patents and concepts related to supercharged engines, but there are few real models, and even fewer serial ones. All the more interesting is one of the new patents from Harley Davidson, describing the company’s plans to install superchargers on large V-twins. The patent does not clarify whether it is a Touring series or a Softail, and whether the current versions of the engines will be equipped with supercharging or the next, updated ones. But it reveals the very fact that Harley Davidson developed supercharging for their engines, as well as a number of its design features.
Numerous sketches show the blower itself (64), the mechanical pulley driving it (88), and the inlet and outlet ports (68, 72). In short, the engine’s crankshaft drives the supercharger via a shielded belt drive (ie, the supercharger depicted in the patent is a mechanically driven crankshaft compressor). The air entering through the filter is compressed in the supercharger and enters the combustion chamber through the intake manifold directly, which means that there is no intercooler in the circuit, which means that the compressor’s performance is not the highest. It is a perfectly justified decision, given the low revs at which V-twins work.
Of course, the drive belt will stretch. This is compensated for by a self-adjusting attachment to the engine body, in which a spring biases the supercharger as the belt is pulled, thereby maintaining tension. The design looks pretty simple and reliable, but one question remains – why?
Is Harley planning supercharger engines as high-performance powertrains for some sort of sports bike? Perhaps to participate in some popular American races like King of the Baggers? Or are they setting the stage for cleaner engines that meet increasingly stringent environmental standards? In any case, it is interesting to observe the development of technologies in this direction, and we hope to see their implementation in the very near future.