Development of a New Multi-Mode Variable Valve Timing Engine

Electrohydraulic Valve-trains for Direct Injection Compression Ignition Camless Engine Operations - Phase I Project Final Report

“…Dresner a al [ 9] cites a 50% increase in low speed torque and an average torque increase over the entire speed range of 10%. Urata et al [52] and Hatano et al [15] report 10% and 15% improvement, respectively, in the low speed torque. Kreuter a al [24] obtained 33% higher IMEP at 1000 rpm due mainly to higher volumetric efficiency and a minimized residual gas fraction.…”

The effects of residual gas trapping on part load performance and emissions of a spark ignition direct injection engine fuelled with wet ethanol

“…One of the most basic variable valve actuation mechanisms is based on cam profile switching (CPS), initially proposed by Honda with its VTEC system. It has two discrete intake cams with different profiles designed for low load/speed (small lift and shorter duration) and high load/speed (high lift and larger duration) [28]. These systems provide low load higher efficiency by partial dethrottling which reduces pumping work (the term de-throttle is used to denote wider throttle opening while unthrottled is used to denote WOT condition with load control through other means than throttling).…”

Estimation of Fuel Economy Improvement in Gasoline Vehicle Using Cylinder Deactivation

“…More of them were focused on the cylinder deactivation mechanism [9][10][11], the noise, vibration, and harshness due to cylinder deactivation operation [12,13], misfire detection [14], or air fuel ratio control logic [15]. The fuel economy improvement of cylinder deactivation presented by previous studies was between 6% and 22%, and it significantly varied depending on the characteristics and control of the applied vehicle [16][17][18][19][20]. In particular, the fuel economy improvement was much different depending on the cylinder deactivation control method.…”