Effect of HHO on four stroke petrol engine performance

Contemporary research into alternative sources of energy for transportation focuses mainly on electric/battery, hybrid and hydrogen powered vehicles. Such focus assumes that the current technology has to be discarded and cannot be improved. However, it is possible to introduce interim technology to alleviate the current challenges arising from continued reliance on fossil fuels. Such challenges include increased greenhouse gas (GHG) emissions with consequent global warming and climate change impacts. The purpose of this research work is to determine if the partial inclusion of hydrogen gas (HHO) in a petrol fuelled spark ignition (SI) internal combustion (IC) engine would improve engine performance. If this is possible, old SI technology can be modified to reduce GHG emissions and improve utilisation of fossil fuels which are expected to dominate the transport energy source for at least the next half century. An HHO generator was designed, constructed and mounted in the engine compartment of a 1989 Ford Laser vehicle. This system allowed partial inclusion of HHO gas on demand into the combustion process through the air supply stream. Detailed and comprehensive experimental investigations were conducted for engine speeds ranging from 1000 to 3500 rpm while parameters such as the power output, exhaust gas emissions and fuel consumption were monitored. Results obtained indicated a decrease in hydrocarbon emissions and an increase in power output with an increase in the HHO gas for certain engine operating conditions. However, performance improvement cannot be claimed for all operating conditions, especially under higher loads where the engine ran with a rich fuel mixture. Hence, further work is required, through HHO generator refinement alongside better engine management, to improve the experimental performance and hence further understanding of this technology.