Honda NR500

Honda's 'New Road' (NR) V-four motorcycle engine series started in 1979 with a 500cc Grand Prix racer that used oval pistons. The oval piston allowed for eight valves per cylinder which generated more power due to the increased air / fuel mixture throughput and compression. In 1992 Honda produced around 300 street versions of a 750cc model, the NR (often mistakenly referred to as the NR750), with a 90-degree V angle, the bike became the most expensive production bike at the time when it was selling for $50,000 and with the rarity, they nowadays rarely change hands.