International Journal of Engineering Research and General Science Volume 2, Issue 5, August-September, 2014 ISSN 2091-2730 497 www.ijergs.org The Effect of Engine Temperature on Multi Cylinder SI Engine Performance with Gasoline as a fuel Sunil Choudhary 1 , A.C. Tiwari 2 , Ajay Vardhan 3 , Arvind Kaushal 4 University Institute of Technology-RGPV, Bhopal (M.P.)-462036 1 2 3 IGEC, Sagar, (M.P.) 4 -470004 Email: Corresponding Author: a_v1986@rediffmail.com Contact No. – 07566476384 Abstract- This country is amongst the tropical countries where the deviation in the temperature is having very vast range. Looking in to this vast varying temperature range it is very difficult to say that which temperature is best suited for operating condition of engines and gives us best performance level as for as Thermal efficiency and brake power is concerned. In this work it tried to investigate the best option to run the S.I. engine. The development of engines with its complexity of in-cylinder processes requires modern development tools to exploit the full potential in order to reduce fuel consumption. A three cylinder, four stroke, petrol carburetor Maruti 800 engine connected to eddy current type dynamometer for loading was adopted to study engine power. The performance results that are reported include brake power and specific fuel consumption (sfc) as a function of engine temperature; i.e. 50, 60, 70, 80, and 90°C with varying engine speed of 1500, 1800, 2100 and 2400 rpm. The effect of increasing the temperature can have the multiple advantage of reducing the specific fuel consumption while on the other hand low head temperature will have good impact in reducing the thermal stress of the top portion, reduction in chance of knocking & pre-ignition, increase in the volumetric efficiency. It is indisputable conclusion that lower speed engines and large capacity engines, which are usually of low speed design, more efficient than high speed engines. Keywords- Thermal Efficiency, S.I. Engine, Fuel, Engine Temperature, Four Stroke, Eddy Current, RPM INTRODUCTION We have two types of internal combustion engines, the spark ignition, SI, and the compression ignition, CI. Both have their merits. The SI engine is a rather simple product and hence has a lower first cost. The problem with the SI engine is the poor part load efficiency due to large losses during gas exchange and low combustion and thermodynamics efficiency. The effect of increasing the liner temperature can have the multiple advantage of reducing the specific fuel consumption, while on the other hand low head temperature will have good impact in reducing the thermal stress of the top portion, reduction in chance of knocking and pre ignition, increase in the volumetric efficiency. The experimental study is carried out on a three cylinders, four stroke, petrol carburetor water cooled, Maruti800 engine connected to eddy current type dynamometer for loading. The objective of this project is to examine engine performance parameter specific fuel consumption (SFC), brake power (BP) and with varying engine temperature at 50, 60, 70, 80, 90 o C and at an engine speed of 1800, 2100, 2400 rpm with respect to engine load 6, 9, 12, 15 kg. The results are shown by various graphs i.e. between engine temperature and specific fuel consumption, engine temperature and brake power, engine speed and specific fuel consumption, engine speed and brake power, engine load and specific fuel consumption, engine load and brake power. There are two types of engine cooling systems used for heat transfer from the engine block and head; liquid cooling and air cooling. With a liquid coolant, the heat is removed through the use of internal cooling channels with in the engine block. Liquid systems are much quieter than air systems, since the cooling channel absorbs the sounds from the combustion process. However, liquid systems are subject to freezing, corrosion, and leakage problems that do not exist in air system. The performance of the engine-cooling system has steadily improved as the power output & density of internal combustion engines gradually increases. With greater emphasis placed on improving fuel economy & lowering emissions output from modern IC engines, engine downsizing & raising power density has been the favored option. Through this route, modern engines can attain similar power outputs to larger convectional engines with reduced frictional losses.