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Strategies to suppress knock have been extensively investigated to pursue thermal efficiency limits in downsized engines with a direct-injection spark ignition. Comprehensive considerations were given in this work, including the effects of second injection timing and injector location on knock combustion in a downsized gasoline engine by large eddy simulation. The turbulent flame propagation is determined by an improved G-equation turbulent combustion model, and the detailed chemistry mechanism of a primary reference fuel is employed to observe the detailed reaction process in the end-gas auto-ignition process. The conclusions were obtained by comparing the data to the baseline single-injection case with moderate knock intensity. Results reveal that for both arrangements of injectors, turbulence intensity is improved as the injecting timing is retarded, increasing the flame propagation speed.

The new Beijing Automotive Industry Corporation (BAIC) engine, an evolution of the 2.3L 4-cylinder turbocharged gasoline engine from Saab, was designed, built, and tested with close collaboration between BAIC Motor Powertrain Co., Ltd. and Southwest Research Institute (SwRI®). The upgraded engine was intended to achieve low fuel consumption and a good balance of high performance and compliance with Euro 6 emissions regulations. Low fuel consumption was achieved primarily through utilizing cooled low pressure loop exhaust gas recirculation (LPL-EGR) and dual independent cam phasers. Cooled LPL-EGR helped suppress engine knock and consequently allowed for increased compression ratio and improved thermal efficiency of the new engine. Dual independent cam phasers reduced engine pumping losses and helped increase low-speed torque. Additionally, the intake and exhaust systems were improved along with optimization of the combustion chamber design.

The Oil Certification Committee of the National Marine Manufacturers Association has developed FC-W®, a new standard for crankcase lube oil used in four-stroke cycle inboard, outboard, and sterndrive marine engines. A sub-committee representing the marine engine industry, the oil industry, oil testing laboratories, and the NMMA engineering standards group was formed to study the lubrication and corrosion prevention needs of four-stroke cycle engines. The sub-committee developed a rust test and an engine test as well as adopting 3 industry standard bench tests. These tests, together with formulation restrictions are used to identify oils that meet the requirements for use in four-stroke cycle marine engines. This paper gives an overview of the development of the new tests, formulation restrictions, and product approval system.