The most extraordinary feature was the engine. The maximum number of cylinders allowed was four, and Honda arranged them in a compact 90-degree vee. But what cylinders they were! They weren’t round.
To flow enough gas to combat the two-strokes, which fired twice as often, not only did the rev ceiling have to be beyond 20,000 rpm, but massive valve area was required. Honda achieved this with eight valves per cylinder, and to accommodate them, the pistons were flat-sided ovals, with two connecting rods apiece. You could describe it as a V8, but with only four cylinders.
The NR was a mighty achievement, demonstrating Honda’s independent (even pig-headed) thinking and unswerving integrity. And it had with the right horsepower numbers to take the fight to Suzuki and Yamaha.
Yet it was a mighty failure for all sorts of reasons. Embarrassingly, it barely qualified for its first GP, at Silverstone, in the presence of the retired founder Soichiro Honda. Fuelled for only a couple of demo laps, Takazumi Katayama managed that, but Mick Grant’s second bike crashed on the first corner, and caught fire. It was a debut as embarrassing as that of the BRM V16 29 years before, and at the same circuit.
When it failed to qualify for the next race at Le Mans, Honda withdrew to return in 1980, with not much more success.
There were many difficulties. Firstly, it was difficult even to start (GP races at the time had dead-engine push-starts), let alone ride. As one of the first riders Grant put it, “you had to be a bit of an athlete”.
Secondly, the power band was extremely narrow – between around 17,000 and 21,000rpm (tick over, with no flywheel, was 7,000rpm!). With a maximum of six gears allowed by regulations, this kept the rider very busy, while the torquier two-strokes were driving off the corners relatively calmly.
Thirdly, in its earlier phase, reliability was poor, and the rev-hungry engines required frequent replacement. Given the difficulty of access, this was a major task.
The NR500 never scored a single point, but might have achieved reliability and even success with further development. But it was too much of a gamble. Honda had to make a fresh decision.
If you can’t beat the two-strokes, then you must join them.