Two fundamental methods of improving the brake specific fuel consumption of a spark ignition engine at part load have been investigated. These comprise the reduction of pumping losses by variable intake valve timing and changes of clearance volume to increase the expansion ratio. The resulting Otto-Atkinson cycle engine competes with the Diesel cycle engine.Test bed results from a four cylinder engine are reported which largely confirm previous predictions from thermodynamic cycle simulation. The interactive effects between cylinders on pumping loss and mixture requirements are discussed.These results show that brake specific fuel consumption improvements of up to 13% are obtainable from variable valve closure delay alone at some operating points over the usual range of speed and load, and that an additional variable clearance volume control can increase this to a maximum of 20%. It is noted that possible requirements for good manifold design may be different from those in current conventional engines.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Variable Valve Closure Timing for Load Control and the Otto Atkinson Cycle Engine


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    SAE International Congress and Exposition ; 1989



    Publication date :

    1989-02-01




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Variable Valve Closure Timing for Load Control and the Otto Atkinson Cycle Engine

    Saunders,R.J. / Abdul-Wahab,E.A. / Univ.of Sheffield,GB | Automotive engineering | 1989



    Investigations of Atkinson Cycle Converted from Conventional Otto Cycle Gasoline Engine

    Feng, Renhua / Li, Yangtao / Yang, Jing et al. | British Library Conference Proceedings | 2016


    Investigations of Atkinson Cycle Converted from Conventional Otto Cycle Gasoline Engine

    Zhang, Daming / Zheng, Guangze / FU, Jianqin et al. | SAE Technical Papers | 2016


    Optimization and Pumping Loss Analysis on Atkinson Cycle Engine Considering Valve Timing and EGR

    Gao, Ying / Xu, Yingjian / Men, Xin et al. | British Library Online Contents | 2018