Agricultura – Ştiinţă şi practică no. 1- 2(89-90)/2014 Agriculture - Science and Practice - 59 - RESEARCHES REGARDING THE CONSTRUCTION OF THE INDICATED DIAGRAM AT COMPRESSION IGNITION ENGINES WHITH FUEL BASED OF UZED COOKING OIL IN RELATED WITH DIESEL Todoruţ A., N. Cordoş Technical University of Cluj-Napoca, Faculty of Mechanical Engineering, Department of Automotive Engineering and Transports, Romania, adrian.todorut@auto.utcluj.ro, Nicolae.Cordos@auto.utcluj.ro Abstract. In this paper are presented the results about indicated diagram, in p-ϕ and p-V coordinates of Lombardini monocylindric engine 3LD 450, alternativ cherge whith biodisel obtained from uzed cooking oil and diesel. The results reveled on this path shows that the function of the compression ignition engine whith biodisel is compared with from uzed cooking oil is compared whith the function of diesel engine. Keywords: compression ignition engine, diesel fuel, used cooking oil, biodiesel, diagram indicated INTRODUCTION Due to the reduction of petroleum fuel reserves, the main aim of this paper is to contribute to research on finding and developing alternative sources of energy in compression ignition engines. A good example is biodiesel made from used cooking oil. In the food industry is used a large amount of vegetable oil, which once used can not be reused and is considered toxic waste, carcinogenic and poses a real source of environmental pollution. Worldwide, it is considered absolutely necessary recycling of waste types. Recovery of (collection) used cooking oils in industrial food preparation processes considered necessary in our country. Such actions, to be extended to the population through the creation of collection centers waste vegetable oils, can contribute to the development of alternative energy sources for compression ignition engine engines. The production and use of biofuels in the field of transport is achieved in a complex system, integrated with strong connections between all levels of the system and able to generate the creation of new jobs. Within theoretical investigations [8, 9] on the duty cycle of engines revealed that they can operate with fuel-based cooking oil. Achieved results of D-2402.000 engine when using biofuels based on cooking sunflower were lower than those obtained when using diesel fuel (Table 1) [8, 9], but encouraged further research in this respect, by lifting the indicator diagram shows compression ignition engines fueled by diesel and biodiesel alternative cooking oil. Certain physico-chemical characteristics of the fuels used in the tests are shown in Table 2 [1, 8, 11]. The fuels used in the tests were judged on the raw material, such as: M 100 (100% diesel fuel - Euro-Diesel, Type II) and FSU 100 (100% biodiesel based on used cooking oil). The engine used in the experimental research, for lifting diagram shows the coordinated p-ϕ and p-V was Lombardini 3LD 450 single cylinder engine.