A micro-hole nozzle and an ultra-high injection pressure were employed to investigate the effects of the nozzle hole diameter and injection pressure on the spray, mixture formation, and combustion processes. The laser absorption-scattering (LAS) technique was adopted to obtain the qualitative and quantitative information on spray characteristics. A high-speed video camera system was employed to record the auto-ignition and combustion processes. OH chemiluminescence was used as a marker of the auto-ignition and as a measure of the flame lift-off length. The effects of injection parameters on auto-ignition and flame lift-off length were presented. The data on gas entrainment and fuel vaporization acquired in the evaporating sprays under the same ambient conditions were correlated to the auto-ignition process and flame lift-off length.
Pressures for improved emissions system performance and increased fuel economy are driving modern engine oil formulations to lower levels of ZDP and lighter viscosity grades. Both trends could lead to increased wear. Therefore, a test was sought to provide precise quantification of the wear performance of modern oils with low levels of ZDP under realistic conditions. The Sequence IVA engine platform (Nissan KA24E) was used in combination with a radionuclide labeling technique called surface layer activation. The work demonstrated how ZDP level and other formulating variables affected wear and identified several highly efficacious new antiwear components.