Search Results

Potential benefits of Variable Compression Ratio (VCR) spark ignition engines are presented, based on an examination of the relationship between Compression Ratio, BMEP and spark advance at light load and full load. Alternative methods of implementing VCR are illustrated and critically examined. System control strategies are presented. Potential manufacturing constraints are identified and their influence on system configuration is examined. Fuel economy benefits attainable from other technologies such as cylinder deactivation, camless valve operation and GDI are shown to be inferior to the use of downsized boosted engines. VCR is identified as the key enabling technology of such downsized engines.

The design, development and manufacture of a new V-10 concept engine is described. The specification is outlined, the main features detailed and the installation in a demonstrator vehicle is described. The engine has production representative performance feel, NVH and package with minimal modifications to the donor vehicle. The project management techniques that enabled the engine to be designed, manufactured, installed and calibrated within a one year time scale are described.

The paper describes the addition of twin balance shafts to the Ford 2·3I DOHC 4-cylinder engine. The conversion of a production engine involves overcoming severe component packaging constraints. This is coupled with the need to ensure that the performance of existing engine systems, particularly lubrication, are not compromised, and the requirement to minimise disruption to current manufacturing processes. The system achieved 92·5% balance of secondary forces - the maximum attainable within packaging and oil aeration constraints. A substantial improvement in vehicle noise, vibration and harshness was recorded.