Honda: From Screamer to Big Bang
The 1990s would see some of the best 500 two-stroke racing bar none and three names would come to dominate at least half of that decade. Wayne Rainey would pilot the Yamaha YZR500 captivating all who watched him, Kevin Schwantz would fight with his all-or-nothing style, and Aussie Mick Doohan would demonstrate an eponymous rough-as-guts approach to racing the likes of which had seldom, if ever, been seen before.
This was an era when satellite teams were to receive seriously competent bikes from their principals and as such the racing was both intense and entertaining. Honda was effectively involved, hands on, with three teams: La Cinq/ROC, Campsa Banesto and Rothmans Honda, the latter staffed by Wayne Gardner and Mick Doohan. The 1990 NSR500 was now delivering some 200bhp which equated to a frankly astounding 400bhp/litre. To put this in some form of perspective just five years previously Freddie Spencer had been riding a threecylinder NS500 that was making just 140bhp; Honda may have come late to the game where two-strokes were concerned, but had certainly mastered the art. The V4 engine still featured a single crankshaft but now the pistons were arranged in two sets of pairs set at 180 degrees apart. The new set up became known as ‘The Screamer.’
The logic behind this then radical system was that the power pulses from the motor would be less dramatic, which would then give both the rider and the rear tyre an easier time. Once again horsepower was beginning to overcome both chassis and tyre technology in a repeat of the early 1970s. The pre-1990 NSR500s had fired every quarter turn of the crank, i.e. every 90 degrees which, although a logical arrangement, from an engineering perspective made for an unpredictable ride. This new, left field approach to the task of getting the power down in a less volatile manner would lead to another, very critical, revision of motor two years later.
Wayne Gardner had a difficult season beset by injuries, yet managed to salvage something in front of his home crowd at the Australian Motorcycle Grand Prix on Phillip Island. Beating his team mate and compatriot Doohan, Gardner had to ride for much of the race with his bike’s fairing trying to fall off! Looking at the results sheet for the season showed just how consistent results always deliver. Yamaha’s Wayne Rainey would score mostly firsts and second places along with a pair of thirds and just one DNF. Four DNFs but numerous first places saw Suzuki and Kevin Schwantz grab second place at the end of the season with Doohan third and Gardner fifth. 1990 wasn’t destined to be Honda’s year; Rainey was at the top of his game and Schwantz was fighting for every win or podium he could get.
The year 1991 showed that Honda’s adoption of The Screamer motor was starting to pay off. Mick Doohan managed to get the most from the new engine and developed a style that suited the bike which, in turn, delivered a more consistent ride at a variety of circuits. With just a single DNF at Assen, Holland, three outright wins, four second places and a trio of thirds, Doohan and the NSR500 finished second to Rainey but crucially beating Schwantz and the Suzuki. Gardner once again could only manage fifth and was close to the end of his GP career but would go on to win two more Suzuka 8 Hour races before retiring from two-wheel sport at the end of the 1992 season.
Honda had been working hard behind the scenes to improve the handling of its 500 GP bike and especially so given that Wayne Rainey’s fluid style seemed to work so well with the good-handling YZR500; it was once again evident that raw horsepower alone wasn’t the answer to winning and retaining GP titles.
The endurance race bikes Gardner and colleagues had campaigned at the likes of Suzuka helped HRC to develop a new GP race frame based around the hugely successful RVF750 RC45 and this was married to yet another revised engine. The Screamer was changed to now fire all four pistons closely together rather than in two timed bursts 180 degrees apart. The new power unit swiftly became know as the ‘Big Bang’ engine and one again transformed how engineers looked at GP engines.
The new technology improved both rear tyre grip and life by reducing the incessant stresses on the rubber, thereby allowing it some ‘down time’ between power impulses. The 1992 season promised to be something rather special, hopefully.
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