BMW Motorrad is apparently working on a triple-cylinder motorcycle engine, a set patent drawings have revealed BMW has been working on a radical new three-cylinder engine.
When BMW dropped the BMW R1200C from its line-up in 2004, it was because the German company didn't want to follow the big-capacity cruiser trend. BMW said developing an engine to match Kawasaki's Vulcan 2000 and Triumph's Rocket III was not a priority. These latest patent drawing can indicate priorities have changed.
Two patents have been filed, both showing variations on the idea of a W3 engine: a V-twin with a third pot placed in the middle to create a W-formation. The idea of a W3 engine isn't a new one. Anzani produced a motorcycle with a W3 engine bit over hundred years ago. More recently, American engine expert Jim Feuling created a Harley-Davidson-based W3, which is available to custom builders will to part with a lot 2,4 million THB (US$ 75,000) asking price.
Moto Guzzi also made a prototype W3 engine in 1982 the W103. The engine was designed to run longitudinally, with the first and third cylinder sticking out the sides in typical Moto Guzzi fashion.
The huge difference between these designs and BMW's patented W3 is that BMW's design doesn't put all three cylinders onto a single crank pin. The first drawing shows each cylinder with its own crank pin, similar to an in-line triple. This approach provides complete freedom with cylinder firing intervals. The firing could be timed to give either a V-twin throb or a smoother delivery. The second version is even stranger as the front and rear cylinders share a crank pin, as per a normal V-twin engine, while the vertical middle cylinder is attached to a separate crank pin – offset by approximately 90º from the first.
While other W3 designs tend to have a 90º angle between the front and rear cylinders, it makes packaging it into a motorcycle tricky. The BMW design appears to be around 60º. Splaying the cylinder will allow the engine to be significantly narrower than a inline-triple design.Tag: EngineBMWTriple-CylinderW3Patents