In the Miller cycle, the intake valve is left open longer than it would be in an Otto cycle engine. The engine has cylinders with bore and stroke 105x128 mm, nominal power of 180 kW at speed of 2300 RPM.
The studies were conducted at 30...70% of the rated load and engine speed of 1400...1800 RPM.
Air excess ratio was changed by variation of fuel supply rate at constant throttle position and it was calculated as ratio of real air consumption to theoretically required to full combustion of expended fuel.
The results of measuring concentrations of toxic components before and after the catalyst according to the excess
air ratio are shown in Figure 2.