Volvo's MEP and PCP Engines: Combining Environmental Benefit with High Performance 910010
In two research programs, Volvo has investigated high performance turbocharged versions based on the new 3-litre inline six-cylinder naturally aspirated engine. Power and torque targets were 180 kW and 385 Nm respectively, with a wide usable torque range.
The MEP-(Methanol Environment Performance)-project was linked to alternative fuel studies and focused on methanol (M85) and Flexible Fuel Vehicle-(FFV)-development.
With alternative fuels, it is important to investigate not only the emissions and fuel efficiency, but also the performance potential, in particular when used in turbocharged engines. The MEP-engine could be reduced to 2.5 litre displacement, due to the good specific performance with M85 fuel. Higher charge pressures could be used compared to gasoline. An M85 turbocharged high performance engine must be designed for higher peak combustion pressures.
For the MEP-engine a series-sequential turbo system was developed, resulting in particularly good low end torque characteristics.
The PCP-(Power Concept Project)-program was focused on the development of a high torque, wide operating range engine version, with high fuel efficiency and low emissions, running on unleaded 95 RON gasoline.
The PCP version retained the 3-litre swept volume, and a parallel-(bi-turbo)-twinturbocharging systemwas developed for good overall efficiency.
Both the PCP and MEP engines easily attained 200 kW and 400 Nm. In practical use, both engines can be compared with much larger N/A versions in regard of usable transient performance.
The PCP-engine had nearly the same fuel efficiency as the N/A reference engine, showing only 2-3% increased fuel consumption in cycle testing.
Better efficiency and considerably more power could therefore be obtained with the MEP version, compared to the reference engine.
Citation: Backlund, O., Keen, P., Rydquist, J., Giselmo, K. et al., "Volvo's MEP and PCP Engines: Combining Environmental Benefit with High Performance," SAE Technical Paper 910010, 1991, https://doi.org/10.4271/910010. Download Citation
O. Backlund, P.R. Keen, J.E. Rydquist, K. Giselmo, L. Sundin
Volvo Car Corp., United Turbine AB
Fifth Autotechnologies Conference Proceedings-P-238