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This paper presents the findings of research into real-world emission levels of a typical EURO-IV passenger car in the United Kingdom (UK). Four real-world drive cycles representing typical urban driving in the UK were used for the experiments. The work identified that the real-world emission levels of a EURO-IV vehicle in the UK are significantly higher than the certified legislative emission levels. The present work also identified that tailpipe-out carbon monoxide is the most affected emission specie in a gasoline-powered vehicle for real-world driving conditions.

Heat transfer coefficients have been measured on the gas side of pistons and liners, the water side of liners, and the oil side of pistons. A significant radial variation in heat transfer across the piston crown has been found. The position of the maximum heat transfer coefficient appears to be coincident with the maximum air concentration, or the position the tips of the fuel sprays have reached at the time of ignition, and the radial variation of heat transfer is possibly related to the amount of fuel burnt at each radius. For four-stroke engines, equations are presented to describe this variation. Heat transfer coefficients at the exposed section of the liner have been found to be similar to the values at the outer edge of the piston. Heat transfer between piston undercrown and cooling oil has been measured for various types of cooling arrangement and, for jet cooling, an expression has been suggested for the heat transfer coefficient. Equations have also been derived to enable coefficients to be predicted for heat transfer from liner to cooling water.

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A detailed knowledge of the combustion processes is essential for the continued development of the medium-speed diesel engine. This paper describes the development and use of electronic and photographic techniques on a constant volume bomb and an 8-in bore diesel engine. Both Schlieren and direct photography were used to study fuel-spray formation and penetration. An equation to predict the motion of vapour in the spray is proposed. Using the knowledge gained, improvements of combustion in existing engines and its extension to high brake mean effective pressure (b.m.e.p.) engines are discussed. Of particular interest are the results obtained from engines of up to 12 1/2-in bore running at a b.m.e.p. of 300 lb/in2.