King D. Eng

Engine Test Procedures to Evaluate Octane Requirement Increase and Intake System Cleanliness

These deposits, especially those on the intake valves, may cause poor cold start driveability, losses in power and fuel economy. Modern gasolines have multi-functional additives to provide all-around performance in areas of detergency, corrosion inhibition, stability, etc. Some of these gasoline additives may inadvertently cause unusually high increases in intake valve deposits and adversely affect the octane requirement of the engine. Dynamometer engine test procedures have been developed to evaluate the performance of gasoline additives in these areas. This paper describes the details of the test procedures, their repeatability and typical test results

Emissions of toxicologically relevant compounds using fischer-tropsch diesel fuel and aftertreatment at a low NOx, low power engine condition

Previously we reported (SAE Paper 2005-01-0475) that emissions of toxicologically relevant compounds from an engine operating at low NOx conditions using Fischer-Tropsch fuel (FT100) were lower than those emissions from the engine using an ultra-low sulfur (15 PPM sulfur) diesel fuel (BP15). Those tests were performed at two operating modes: Mode 6 (4.2 bar BMEP, 2300 RPM) and Mode 11 (2.62 bar BMEP, 1500 RPM). We wanted to evaluate the effect on emissions of operating the engine at low power (near idle) in conjunction with the low NOx strategy. Specifically, we report on emissions of total hydrocarbon (HC), carbon monoxide (CO), NOx, particulates (PM), formaldehyde, acetaldehyde, benzene, 1,3-butadiene, gas phase polyaromatic hydrocarbons (PAHs) and particle phase PAHs from a DaimlerChrysler OM611 CIDI engine using a low NOx engine operating strategy at Mode 22 (1.0 bar BMEP and 1500 RPM). Mode 22 did produce some differences in emissions levels and aftertreatment performance for toxicologically relevant species compared to Modes 6 and 11. Further, uncontrolled step changes in these emissions were observed to occur at the low exhaust temperature of Mode 22. Nevertheless the emissions for Mode 22 with Fischer-Tropsch diesel fuel were generally consistent with Modes 6 and 11.