Optimization Techniques and Results for the Operating Modes of a Camless Engine

Electronic control of valve timing and event duration in a camless engine enables the optimization of fuel economy, performance, and emissions at each engine operating condition. This flexible engine technology can offer significant benefits to each of these areas, but optimization techniques become crucial to achieving these benefits and understanding the principles behind them. Optimization techniques for an I4 - 2.0L camless ZETEC dynamometer engine have been developed for a variety of areas including:

• Cold Starts
• Cylinder Deactivation
• Full Load
• Idle
• Transient A/F control

The procedure for the optimization of each of these areas will be presented in detail, utilizing both steady state and transient dynamometer testing. Experimental data will be discussed and the principles governing the response of the engine will be explained. Selection criteria for determining an optimum strategy for the different modes will be presented and recommendations will be discussed. Conclusions will show that a camless engine improves performance, offers significant fuel consumption benefits, improves transient control, and is beneficial in reducing emissions during the cold start and warmed up conditions.