Lower Emissions with DLC Coatings - Frictional Behaviour within Valve Train

The results are presented of an investigation into the effects of Diamond-Like Coatings (DLC) on the frictional behaviour of components within the valve train of a production engine. Components from a 40-cylinder, 1.6 litre Peugeot petrol engine were coated with Bekaert's Dylyn Plus, a coating specifically aimed at high volume automotive applications and with properties that can be tuned precisely to match the customer's needs. Tests were run on an electrically driven test rig using coated and uncoated mechanical and hydraulic tappets. The results were measured at 20, 50, 80 and 120degreesC where 20degreesC was considered to be a normal start-up engine temperature and 80 - 120degreesC the normal working temperature for an engine. The results for torque reduction are presented graphically. In the low rpm range friction reduction, and therefore energy requirement, was reduced by 24 per cent but this decreased with higher rpms. It is estimated that a reduction in fuel consumption of 1-2 per cent could be achieved implying a reduction in carbon dioxide emission of 2-3 per cent. It is suggested that the benefits of DLC coating would be most beneficial to smaller petrol cars.

  • Authors:
    • BOGHE, M
  • Publication Date: 2009-4


  • English

Media Info

  • Pagination: 38-41
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 01146997
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Dec 24 2009 8:36AM