That the average gasoline-fuelled race engine is no more than about 28% efficient is a source of great angst to many power unit engineers. But while the best will claim 37-38% and the worst nearer 20%, the inescapable fact still remains that the vast majority of energy available from the fuel is lost in the form of heat. Split evenly between heat in the exhaust gas and that delivered up to the cooling water jacket, that means for a 450 kW race engine somewhere in the region of 500 kW of...
Opinion is divided on the need to have even firing intervals for engines. With very few exceptions, road vehicle engines fire at equal intervals, while many two-cylinder engines fire at unequal intervals, and some three-cylinder engines in the past have also had some very odd firing orders. The current Yamaha R1 is a four-cylinder engine that has made use of a cruciform crankshaft to give an uneven firing order. This was based on the successful YZF-M1 MotoGP race bike that enjoyed world...
I'm sure you'll agree when I say the environment alongside a race engine isn't the most electronics-friendly of places. Heat and high levels of vibration are traditionally the enemies of anything electronic, and consequently the technology of producing robust sensors for engine management systems must be a particular challenge. Because of its critical function therefore, a prime example here is the engine speed/timing sensor. Designed to provide the engine control ECU with...
As I described in my previous article, there were (and are) many enthusiasts out there creating their own race engines. Historically, the racing series with the most open regulatory books have been those based on these DIY race engines. One such series with lots of birth certificates for engines originated in the late 1980s, and was the Sound of Singles Series, later called Supermono. This motorcycle series mandated single-cylinder four-stroke engines without forced induction. Later the...
This year, for the first time in many decades, we find ourselves without a two-stroke engine in the Grand Prix classes of motorcycle road racing. For lovers of diversity in engineering in general and engines in particular, the class of 2012 Grand Prix bikes are perhaps a disappointment. Having seen the two-stroke bikes regulated out of existence with the demise of the 500 cc and 250 cc World Championships, 250 cc four-stroke single-cylinder engines have come to replace the 125 cc...