The Merritt Unthrottled Spark Ignition Combustion (MUSIC) engine, invented at Coventry University has, for the first time, undergone formal evaluation tests in a four cylinder form.
The MUSIC cylinder head was developed by Powertrain Technologies near Norwich with the aid of a grant from the Energy Saving Trust.
MUSIC is a petrol engine able to operate completely unthrottled and can come close to achieving the fuel efficiency advantages of the diesel engine.
In tests conducted recently at an independent test facility, the four cylinder MUSIC engine, mounted on a Ford Mondeo crankcase, achieved a 19.8 per cent improvement in fuel economy averaged over a range of operating conditions, known as the minimap, in comparison with a conventional petrol engine. Both engines were naturally aspirated (not turbocharged).
The comparison was made against a current Ford 2.0lt Duratec engine as fitted to the Mondeo car. The 20 per cent improvement was calculated over a number of test points encountered in urban drive cycle, known as the NEDC. The thermal efficiency increases as the engine load decreases and at near idling condition the fuel saving offered by MUSIC measured was an impressive 42.5 per cent.
Andrew Barnes, the managing director of Powertrain Technologies, is confident that, in view of these results obtained at such an early stage of development, still more improvements, maybe up to 25 per cent, can be achieved in the near future.
'Due to difficulties in obtaining suitable injection equipment we were unable to optimise the engine at certain test conditions. We are confident that there are a few more percentage points available when optimised,' he said.
The four cylinder prototype is based on a cylinder head mounted on a Ford Duratec crankcase. Unlike competing technologies, the MUSIC system does not require any new supporting technology, it requires no additional moving parts, and uses currently available production components throughout.