Three questions for Prof. Dr. Martin Doll, Director of the Institute for Internal Combustion Engines and Vehicle Drivelines at the University of Munich

What were the special challenges in designing the VR6 engine for the new HOREX?

One of them was clearly the compact size of the engine. The outstanding space economy of the VR cylinder configuration forces us to pay very close attention to precision and space-saving design. This was the only way to reduce the dimensions of our six-cylinder engine. At the same time, it enabled us to make the entire bike extremely compact.

How long did it take to complete the engineering?

So far, we've spent around five years on the project. We started with simulations and experimental single-cylinder engines. In this phase, we initially developed the ideal framework parameters. These included the figures for the cylinder angle and offset – which is the all-important angle of the cylinders to the crankshaft in a VR engine. We gradually completed the engine design and worked out the final details around six months ago. Since then we have been busy with fine tuning the motor management and preparing for benchmark testing.

What is your personal highlight in this project?

It's hard to say because the HOREX engine contains so many interesting technical solutions. A lot of detail work was involved in designing the cylinder head. We had to position the 18 radial valves and three camshafts perfectly in relation to the almost perpendicular intake ports. But this was the key to realize maximum power.