THE MOTOGP DEVELOPMENT ENGINE

DEVELOPMENT THROUGH THE AGES

The biggest change in the premier class over the years has been the switch from 4-stroke, to 2-stroke engines, and back to 4-stroke in 2002, reflecting the need for technical progression and innovation in the sport - in keeping with the development of production bikes.





In the early days of the World Championship the premier class was dominated by 4-stroke machinery from mostly European manufacturers. The early 4-stroke engines were cumbersome, heavy, required a lot of maintenance and were never the most reliable of units.
Through the 1960s Japanese manufacturers such as Suzuki and Yamaha started to make their presence felt in the smaller cylinder classes with 2-stroke machinery. The lighter 2-stroke presented more possibilities for tuning and was seen as the future of the sport.
Although the 1970s and even 1980s saw a period of technical change that permitted even private ‘built in the garage’ motorcycles to go Grand Prix racing it was the might of the Japanese engineering and initiative that would soon provide the most competitive racing tools.

THE EMERGENCE OF 2-STROKE

As the Japanese slowly forged ahead with 2-stroke technology, the 4-strokes would fade out in a matter of seasons as the 500cc four cylinder 2-stroke became available on a production scale from Japan.
With the 2-strokes becoming more reliable and more powerful the engines actually threw more emphasis onto the rest of the motorcycle and evolution began at a rapid rate through the 1980s. Tyres, suspension, aerodynamics and even chassis design all saw a wealth of development.
In the early 1990s speeds had reached a peak in MotoGP. The 500cc bikes were harder and faster to ride than ever as an all-Japanese premier class sought to push the performances of the machines to the limit and new heights. By 1992 a breakthrough emerged when Honda started to experiment with a revised firing order on their all-conquering NS500.

BIG BANG & THE SCREAMER
Dubbed ‘Big Bang’ the revised crankshaft mechanism placed an emphasis more on acceleration than outright top speed and Mick Doohan went on to dominate the class on the new bike. Honda also produced a V-twin version of their four cylinder motorcycle which helped privateers remain competitive against the factory bikes and for the first time technical emphasis leaned more towards corner speed than outright horse-power; a trait that remains present to a certain degree in MotoGP today.
By the late 1990s Doohan had reverted back to the ‘harsher’ engine order in his quest for more speed. Nicknamed the ‘Screamer’, this and the ‘Big Bang’ version of the NS500 won World Championships from 1994 to 1999.
In 2000 Suzuki enjoyed a last hoorah on the RGV 500 2-stroke; a motorcycle which developed from predecessors that had originally dominated the class back in the late 1970s and early 80s.

4-STROKE 990cc

With 2-stroke technology reaching a plateau improved 4-stroke engines marked the way forward. The MotoGP landscape changed in 2002 and the last six seasons have again seen a massive acceleration in the technical possibilities with variable cylinder structures and quantities, telemetry, data collection and manually adjustable engine mapping switches now standard.
MotoGP is now a highly evolved and scientific competition with traction control and electronics playing an important role in the delivery of the power and adjusting the balance of the motorcycle to make the best use of the engine’s performance.
The MotoGP category saw the engine size reduced from 990cc to 800cc in 2007, with an aim to reduce speed. So far the speeds have remained the same but the size and dynamics of the new motors have placed more focus on the corner speed of the machinery, as opposed to the brute power of the 990s.
In line with cost reduction policies, engine restrictions have been enforced since 2009 and for the first time in 2010, each rider will only have 6 engines at their disposal for the whole season. Limiting the number of engines means the manufacturers will have to produce more reliable powerplants, which induces reducing their power output and revs, hence slowing down the overall increase in performance of the bikes.
A move to a 1000cc formula is planned for 2012, accompanied with further restrictions than during the 990cc era. The number of cylinders will be limited to 4 and the maximum cylinder bore will be 81mm, for bikes with a minimum weight of 153kg. Under the 2012 technical rules, 800cc bikes will also be allowed with a minimum weight of 150kg.

MOTO2

The Moto2 class, a new 4-stroke 600cc category, was announced in December 2008 and from the start of the 2010 season replaced the 250cc category.
Moto2 is aimed as a prestigious yet cost-effective accompaniment to MotoGP, allowing riders to continue their development on the way to the premier class. The bikes are powered by a 600c 4-stroke Honda engine which produces around 140bhp, with a prototype chassis which is free from limitation and the design and construction of which is free within the constraints of the FIM Grand Prix Technical Regulations.

SMALLER CLASSES

The 125 and the former 250cc classes have remained hosts to 2-stroke engines, being the original homes of the 2-stoke. Firms such as Derbi, Kreidler and Bultaco were 50cc, 80cc and 125cc competitors with 2-strokes in the 1960s and 2-strokes littered the 350cc division.
Outside the premier class 2-strokes permitted the most cost-effective means of racing and being competitive. The 2-stroke prospered with carburetion, tuning and set-up becoming a specialised skill that saw a host of names in the Grand Prix paddock making their names through the late 1970s, 80s and into the 90s.
In modern times the accepted wisdom is that the limits of 2-stroke technology have been largely reached. Honda’s announcement that they will cease development on their quarter-litre bikes perhaps provides proof that there is no further ground for significant progress

source:www.motogp.com