The gasoline internal combustion engine is the global engine of choice for the majority of hybrid and conventional passenger cars and the Ricardo Magma concept is the continuing evolution of that technology to meet the need to improve efficiency and reduce CO2 emissions.
Magma is a combination of two current approaches to gasoline engine efficiency:
- Improving efficiency through compression ratio increase; and
- Downsizing for de-throttling and boosting to maintain performance
The improvement in fuel consumption over the WLTC (Worldwide harmonized Light vehicle Test Cycle) is expected to be in excess of 12% with a projected on-cost below €15 per g/km CO2 (below $9 g/mi at 1.07 $/€). This is achieved whilst retaining an expected 2020 mainstream performance level (for a D-class vehicle) of 140 kW rated power and 280 Nm peak torque from a downsized 1.5 litre, three-cylinder engine. The components in the Magma system are proven in production, thus the development effort can focus primarily on the optimisation of the system, without accompanying concerns regarding technology and manufacturing readiness.
The concept contains a host of newly combined technologies:
- Gasoline direct injection combustion system at 13:1 geometric compression ratio
- Miller cycle via Early Intake Valve Closing (EIVC)
- Cam Profile Switching and Continuously Variable Valve Lift options
- Supercharger plus turbocharger two-stage boosting system with inter- and after-cooling
The Miller Cycle is implemented through modified valve timing events to mitigate the combustion knock at high load that would normally result from the high geometric compression ratio at high specific loads. To compensate for the air-flow characteristic that the modified valve events bring, a two-stage boosting system is employed to enable sufficient performance. The benefit of this combination is improved fuel consumption in real driving conditions, combined with the maintenance of competitive vehicle performance.
Single cylinder research is ongoing, with a multi-cylinder demonstration expected in Q3 2017
Magma Engine Prototype
Please get in touch at [email protected] for more information about this project.