Adaptive Diesel Engine Control Via Variable Valve Timing

Diesel engines are widely used in military and commercial vehicles, as well as some light duty vehicles. The compression ratio is a compromise between power, economy, and cold startability. The optimum ratio for economy is below 15:1, whereas the necessary compression ratio for cold starting ranges from 16 to 22:1 depending on the specific engine design. This is too high for best economy and optimum boost. The proposal objective is to demonstrate a combination of simple mechanisms designed for the Caterpillar C-12 to improve fuel economy particularly during idle as well as improve engine power output. The technology will include varying the compression ratio between high (for cold starting) and low (for warmed-up running). Minimal or no engine block modifications are anticipated. The work proposed is to demonstrate hardware viability in a bench test rig as well as estimate/model fuel economy and power improvement from the proposed technology. For the SBIR OPTION, a system will be installed on one cylinder of a multi-cylinder engine and motoring tests run to demonstrate effectiveness.