The first thing we must consider is if this could ever happen: a Grand Prix bike lining up in an endurance race. We have to start from the premise that a MotoGP bike isn’t designed for a long-distance race such as an endurance race, which can last anywhere between 8 and 24 hours. That means covering far more ground than usual with a MotoGP bike.
With the regulations in force, a MotoGP bike couldn’t race in an endurance race. The basis of endurance regulations is limits it to bikes approved for production categories, for EWC (Endurance World Championship), and Superstock classes, which means prototypes aren’t allowed to compete, such as a MotoGP bike. However, there is a third class called Experimental, where bikes that aren’t production models but which are based on FIM approved motorcycles or are unique prototypes can take part.
The Experimental class has its limitations: three- or four-cylinder production-derived engines from 750 to 1,000 cc can be used, or prototypes from 600 to 750cc of up to four cylinders, or from 750 to 1,200 cc of up to three cylinders. As such, a MotoGP engine, which has 1,000 cc and 4 cylinders, couldn’t take part in an endurance race either.
Even the Honda RC213V-S, which passes for a production MotoGP, couldn’t compete in the Experimental category, because its engine falls outside the regulation requirements.
However, on occasion we have seen a Grand Prix bike line up on the grid of an endurance race. Current regulations are strictly defined and don’t allow any for any leeway, but in the past regulations were far more basic. In endurance racing, the most essential thing was to compete with a production model, and this very basic definition also encompassed 750 cc World Championship bikes, which in reality were authentic Grand Prix motorcycles.
When the category was launched in 1973, one of the regulations established was that prototypes couldn’t compete and that the category would be open to production bikes, and as such, “customer racing” competition motorcycles were admitted. These 750 cc bikes participated in the 1978 Bol d’Or, the oldest ever endurance race, but their two-stroke engines succumbed to the force and demands of the extremely high speeds of the Circuit Paul Ricard, with its long Mistral straight, where the bikes were pushed to the max. That proved that a Grand Prix motorcycle, the sharp and powerful 750 cc and 500 cc “two-strokes”, weren’t prepared for long-distance races.
Another added problem was fuel consumption. The explosive “two-strokes” used far more fuel than the more powerful “four-strokes, which could 90 minutes without refueling, while the 2-strokes had to stop to refuel after 50 minutes, which meant practically doubling the number of stops compared to their rivals. So a lot of what they could gain on the track because of their greater performance, they lost it because of their race strategy, with their repeated stops.
Distancia y exigencia
A MotoGP bike is clearly much more powerful and competitive than endurance bikes, but has to contend with a devastating foe: the race distance. Generally, the winner of a 24-hour race covers a distance of between 3,500 and 4,000 kilometers, and considering the high pace, this places enormous demands on the mechanics.
Grand Prix bikes cover approximately 500 kilometers between the practice and race sessions in a weekend, so in 24 hours of racing they would have to do the mileage of at least seven Grands Prix. You also have to bear in mind that, during the Grand Prix practice sessions, two bikes are equally used, while in endurance there is only one single bike.
Over the course of a MotoGP season, about 10,000 kilometers are covered, spread out among seven engines, so the average mileage of a MotoGP engine is around 1,500 kilometers. It is necessary to use three MotoGP engines to cover a 24-hour race, although these engines could withstand an 8-hour race, such as the Suzuka race, whose distance—some 1,200 kilometers—falls within the mileage range of a MotoGP engine.
Therefore, in order to be able to withstand the race distance, a MotoGP engine would have to operate at a speed much lower than usual—above 17,000 rpm—in order to ensure its survival, so it would lose power and effectiveness, and in turn most of its advantages.
Adaptation to endurance
There are also other conditioning factors that would complicate the existence of a MotoGP bike in endurance. You would have to modify some elements of the bike to adapt it to quick refueling, such as the fuel-filler system—from 2023, all participants in the Endurance World Championship will use an identical approved and compulsory system—and the corresponding wheel assembly and disassembly equipment, which allow them to be changed in a few seconds.
Another matter is the brakes. Carbon discs would suffer enormous wear from such prolonged use, and change the pads is more complex with this material, because it involves changing the discs. Carbon would have to be discarded in favor of traditional steel discs, which are also extremely effective.
Although nothing would prevent MotoGP bikes from continuing to use Michelin tires—in the Endurance World Championship free competition is maintained among tire manufacturers except in the Superstock class—they would also have to adapt to tires with a different make up in order to perform better.
It is true, it would interesting to see how a MotoGP bike held up in an endurance race, but as well as the obstacles in the regulations, modifications would have to be made to the bike to be able to make the race distance. As a result, it would no longer be the MotoGP bike as we know it.