Objective The use of pistons made of fine grain carbon was investigated in a spark-ignition engine. Pistons were designed and manufactured and then tested in a spark ignition combustion engine. Due to the carbon material's lower coefficient of thermal expansion the top land clearance between piston and cylinder can be reduced by a factor of three in comparison to standard aluminium designs. Under stead-state part-load operating conditions the emission of unburned hydrocarbons can be reduced by more than 20% compared to aluminium pistons, without significant penalties in NOx-emissions. Simultaneously, a small improvement in fuel economy of about 2% is observed. At full-load, the blow-by leakage flow is reduced by more than 50% and the piston crown temperature is about 30 C higher with the carbon piston than with the series aluminium piston. The higher piston temperatures were caused by the lower thermal conductivity of the carbon material. The reduction of HC-emission in the FTP-75 test-cycle was 20% during the first 120 seconds. For maximum benefit the carbon piston crown has to be coated, in order to close the pistons porosity. The mechanical stability of the improved carbon piston was successfully tested in a 300 h endurance testing at maximum torque. Fields of science agricultural sciencesagriculture, forestry, and fisheriesagriculturegrains and oilseedsnatural scienceschemical sciencesorganic chemistryhydrocarbonsnatural scienceschemical sciencesinorganic chemistrypost-transition metalsengineering and technologyenvironmental engineeringenergy and fuels Programme(s) FP3-BRITE/EURAM 2 - Specific programme (EEC) of research and technological development in the field of industrial and materials technologies, 1990-1994 Topic(s) Data not available Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator Daimler-Benz AG EU contribution No data Address Epplestraße 225 70567 Stuttgart Germany See on map Total cost No data Participants (4) Sort alphabetically Sort by EU Contribution Expand all Collapse all FREIE UNIVERSITAET BERLIN Germany EU contribution No data Address Kaiserswertherstrasse 16-18 BERLIN See on map Links Website Opens in new window Total cost No data Société Mosellane de Pistons France EU contribution No data Address 57110 Metz See on map Total cost No data UNIVERSITY OF LEEDS United Kingdom EU contribution No data Address Woodhouse Lane LS2 9JT LEEDS See on map Total cost No data University of Warwick United Kingdom EU contribution No data Address Gibbet Hill Road CV4 7AL Coventry See on map Total cost No data
