Large, open chamber Diesel engines are designed with compression ratios of 16 to 18:1 to facilitate cold starting. This is too high for best economy which is 14 to 15:1. Furthermore, these engines are designed for high power for highway vehicles with reserve for hill climbing and maneuvering. The objective is to demonstrate a combination of simple mechanisms designed for the Caterpillar C-12 to improve fuel economy particularly during light load operation as well as to allow improved engine power. One device will allow the compression ratio to vary between high (cold starting) and low (warmed-up running). A second device will disable some cylinders to improve idle and light load fuel economy which is particularly important for military surveillance, but useful for stationary generators and other applications where significant lighter load operation occurs. Minimal or no engine block modifications are anticipated. The work proposed demonstrates hardware viability in a firing engine. For the SBIR Phase II, the technology will be installed on all cylinders of the C-12 engine to demonstrate both compression ratio and disabling effectiveness. Computer modeling will guide the technology design and testing. A relationship with an established company(s) will be formed for manufacturing the technology.
Benefit: Anticipated benefits of the fully developed technology are light load fuel economy improvements of between 15% and 33%, engine power increases more than 5%, and a significant reduction in engine out emissions. These benefits depend on the strategy chosen in consideration of cost, complexity, risk and timing.
Keywords: VALVE, efficiency, ratio, Power, Variable, Compression, Engine, Actuation
