‘FM’ - A High Efficiency Combustion System for the Future Light Duty Engine? 820760
Consideration of the approaching ‘energy crisis’ reveals two requirements for future light duty automotive engines.
maximum economy and
the ability (perhaps with detail design re-optimisation) to accept a range of fuels of petroleum or other extract, of differing ignition characteristics.
One combustion system which meets these requirements is the MAN ‘FM’, the potential of which has already been demonstrated in truck-size engines but on which little information has been published in light-duty engine bore sizes.
The paper describes both design and experimental work carried out to evaluate the application of the FM combustion system to a light duty passenger car engine.
Consideration is given to the critical design parameters associated with the application of the FM system to a multi-cylinder gasoline based engine and how the criteria can be met. Details of the design and construction of a single cylinder derivative of the multi-cylinder engine are given.
Results from the single cylinder engine for a wide range of tests on 91 RON gasoline engine are presented and discussed, with reference to optimum chamber geometry, swirl, injection and ignition requirements, power output, fuel consumption and emissions. Information is also given on the ability of the system to accept pressure charging.