"We looked at the regulations, considered the possibilities … and like Honda we decided that five cylinders was the best option," said Kenny Roberts, himself a former three-times World Champion. Four- and five-cylinder engines have the same minimum weight limit of 145kg. "Given that, why would you want to make a four?" said Roberts.

"Once that decision had been made, the engine architecture was just obvious," he said.

The new four-stroke Proton KR is similar to the Honda in broad outline … a vee configuration with three cylinders forward, two behind. But there are significant differences even in basic architecture, with the Roberts bike adopting a narrower vee angle just for a start.

The Honda has a 75.5-degree angle between the cylinders. "Ours is a 60-degree vee," said Roberts. "We settled on that angle after computer simulations and discussions with our engineers. We believe that it makes a better envelope."

The similarities with the Honda were dictated by the rules. "Once you've decided on five cylinders, the configuration settles itself. In F1 racing they all use V10 engines, but nobody accuses them of copying each other," continued Roberts.

Roberts added that they were aiming away from too much experimental work to rely on proven technology. "We're not trying to re-invent the wheel, as we did with our two-stroke. It's the last thing I want.

"We're a small, independent engineering company, and we're not in a position to spend three years on research and development. That's why we're not looking at F1 technology, like pneumatic valves," said Roberts.

"We want to make something that can run decent from the start."