Hidden depths
Formula 1 is a sport of extremes and an example of that is engine combustion technology. During the course of a Grand Prix, each engine will complete 46,000 combustion events during an average lap. Within the blink of an eye, an F1 engine has completed 200 ignition cycles, and over its four-race cycle will complete 37 million ignitions. As motorsport continues to push the boundaries of combustion efficiency (see p8), engineers need to know what is happening within the combustion chamber. But how do you measure parameters in an environment where temperatures exceed 350degC and pressures are over 35bar? Welcome to the world of in-cylinder pressure measurement.
‘We’ve run cylinder pressure sensors in our engine since 2014,’ reveals Andy Cowell, managing director at Mercedes AMG High Performance Powertrains. ‘They are useful for monitoring the performance and the reliability of the engine, so they get an entry ticket into the bill of materials.
Development journey
‘It’s something the performance guys wanted right from the very start [but] a tough development journey is really the story behind the cylinder pressure sensor. For a start, they are difficult to fit into the combustion chamber. It’s an 80mm bore size and somehow within the cylinder head you have to include two exhaust valves, two inlet valves, a spark plug, fuel injector and a cylinder pressure sensor, which needs to be in a useful location. Coming up with one that tells you what you want to know, and survives, is tough.’
It is these extensive challenges that have made it difficult for
