In order to grasp the possibility of achieving backfire control high performance and low emission in a hydrogen fueled engine using external mixture injection, the effects of increasing the boosting pressure were analyzed in terms of backfire occurrence combus non characteristics and performance enhancement As the results it was found that backfire could be successfully controlled if the IVO time was retarded to or beyond TDC regardless of the amount of supplied energy Also these results show that the achievement of high power (equal to that of a gasoline engine) high efficiency (around 36 7%) and low emission (NO(x) of less than 16 ppm) without backfire in a hydrogen fueled engine is possible with a boosting pressure of 1 5 bar at an equivalence ratio of Phi = 0 35 or lower (C) 2010 Professor T Nejat Veziroglu Published by Elsevier Ltd All rights reserved