International Journal of Engineering and Technology

It is well known fact that about 30% of the energy supplied is lost through the coolant and the 30% is wasted through friction and other losses, thus leaving only about 30% of energy utilization for useful purposes. In view of the above, the major thrust in engine research during the last two decades has been on the development of low heat rejection engines. The Low Heat Rejection (LHR) engine has been given considerable attention recently as engine builders struggle to find remaining avenues to improve economy and lower emissions. The concept of air gap insulated piston has been explored by providing 1mm air gap within the piston by using bolted type piston. The bolted air gap insulated piston provides complete sealing of air gap necessary for continued insulation. The design evolved provides high insulation combining adequate durability. In order to provide high insulation and reliability, proper designing of the air gap piston has to be ensured. The piston with 1mm thickness of air gap are designed with two different material. The insulation provides betterment in fuel consumption at normal operating condition than a conventional piston engine and also the delay period tends to reduce the emissions levels of Hydrocarbons and carbon monoxide. The combustion rate is increased because of insulation and hence there is reduced vibration and noise level.