Horex Resurrected - Special Feature

A hallowed name in the mythology of German motorcycling, the Horex marque was long associated with top-class two-wheeled vehicles, but until recently, that name had almost been forgotten outside of Germany. Established in 1923, the company was very successful up until WWII but was never able to fully recover in the post-war years, limping along until its demise in 1956. Now, more than 50 years later, a group of entrepreneurs, technicians and investors led by CEO Clemens Neese has resurrected the brand. In an effort to make the biggest splash possible, Horex has designed and prototyped the supercharged 1200 VR6 you see here.

For many reasons, the resurrection of legendary makes has been a common occurrence in the world of motorcycling, with once-famous names like Norton, Gilera and Vincent all getting second but shaky new leases on life. More often than not, however, the final result is just another funeral. Neese claims that Horex's multi-million-euro budget will keep it out of the motorcycle graveyard.

We wish them well, because the bike, and in particular the engine, is fascinating stuff. At the center is what looks like a scaled-down 2800cc Volkswagen VR6 engine, a "semi-inline" Six with cylinders set at a very narrow 15-degree Vee.

Despite any similarities in cylinder arrangement, Horex denies that its engine is a direct derivative of the VW unit, not only because of the obvious size and displacement differential, but also in terms of general design. An obvious difference is that the Horex features perfectly downdraft inlet ports and runners compared to the radical side-draft setup on the VW engine.

The VR arrangement has produced a very compact six-cylinder unit: Measured at the head, the 1218cc mill spans only 16.9 inches, a really diminutive size for a Six compared to BMW's K1600GT/GTL inline-Six, which measures 21.8 in. wide. The comparison becomes more meaningful when we consider that despite its larger displacement, the BMW Six features a bore (72mm) that is only 4mm larger than that of the Horex. Another VR6 benefit is that the cylinder layout allows the engine to have highly oversquare bore-and-stroke measurements (68 x 55mm) without the risk of exceeding the limits of a rationally sized motorcycle powerplant.

As if the VR6's cylinder architecture isn't cool enough, induction is via an intercooled centrifugal supercharger (left) that potentially bumps peak output to 200 hp. The Rotrex blower neatly tucks in behind the cylinders (right) and is belt-driven off the crankshaft. The chassis is built around a conventional twin-spar aluminum frame; dimensions have yet to be finalized.

As on the VW engine, the very narrow Vee angle allows all of the cylinders to reside under a single roof. To accomplish this, the pistons have a 7.5-degree slanted crown, and the head requires three camshafts. Induction is via three valves per cylinder--two intake and one exhaust--radially arranged. The center camshaft actuates the exhaust valves of the rear cylinders as well as the intakes on the front barrels. The other two cams actuate intakes at the rear and the exhausts at the front. All cylinders exhale forward into a neatly arranged 6-into-3 exhaust system.

Another cool feature is that the VR6 is force-fed by a belt-actuated centrifugal supercharger run off the crankshaft; the charge is cooled by an air-to-liquid intercooler integrated in the engine's cooling system. Because of the supercharger, the compression ratio is kept at a moderate 9.0:1. Claimed power output is an impressive 175 to 200 hp (depending on boost) at 8500 rpm, with 111 ft.-lb. of torque at an undisclosed rpm. A six-speed transmission and belt final drive transfer power to the rear wheel.

This very impressive power unit is packaged in a conventional chassis, featuring an aluminum twin-spar structure. The prototype shown at Intermot was clearly a wooden mockup, so a lot of details have yet to be finalized.

Clearly, there is a lot of work to be done before this machine can join BMW's K1600GT/GTL and Honda's Gold Wing as the third modern Six on the market, but Horex claims to have engines running on bench dynos and is currently building running prototypes for testing.

We hope that Horex survives long enough for us to sample its fabulously conceived, unique engine and avoids fading back into obscurity all over again.