Universal Journal of Mechanical Engineering 8(4): 237-241, 2020 http://www.hrpub.org DOI: 10.13189/ujme.2020.080409 An Experimental on Small Scale Gasoline Engine Performance Fajri Vidian * , Deli Huda Putra Department of Mechanical Engineering, Universitas Sriwijaya, Indralaya, Sumatera Selatan, Indonesia Received May 6, 2020; Revised June 5, 2020; Accepted June 23, 2020 Copyright ©2020 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Abstract Small-Scale engines are very widely used, especially in developing countries like Indonesia. Its use is intended for various daily activities that require small-scale power. The performance small scale engine is very interesting to investigate for suitable in-field applications. In this study, a small-scale engine was investigated to measure torque (T), brake power (BP), brake mean effective pressure (BMEP) using a rope brake dynamometer with configuration of I. The goal of study is to get an influence of the increase of engine speed on torque, brake power, and BMEP. The experiment was done at engine speed in the range of 1400 to 3500 rpm for each load of 3,4, and 5 kg. The results show an increase in engine speed tends to increase the torque, brake power, and BMEP generated for each load used. The maximum of torque, brake power, and BMEP were 4.53 Nm, 1.67 kW, and 349 kPa respectively at 3521 rpm and the load of 5 kg. The result of brake power of the experiment was compared to report at the literature with differences about 2.3%. The value of BMEP was in the range of standard for small scale engines. This result has given a contribution combined influence of speed and load on the T, BP, and BMEP. Keywords Small Scale, Engine, Torque, Brake Power, BMEP, Gasoline 1. Introduction The use of a small gasoline scale engine is very popular nowadays especially in Indonesia, for use in various field applications such as pump drive, electricity generator, grain crusher, coconut husk peeler, chicken feather release, propeller or boat drive, and others. According to [1] small scale engine has power below 10.4 kW. Correlation of speed and load on torque (T), brake power (BP), and brake mean effective pressure (BMEP) that can be produced by small scale engine is interesting to investigate. Many types of equipment could be utilized to identify the value of torque and brake power on the engine which is one of it is rope brake dynamometer [2]. Until now, many researchers have used rope brake dynamometer to present the value of the T and BP on small scale engines [3]. It is caused by the easy design and fabricated. Several researchers have investigated the torque, brake power and BMEP on the gasoline engine. Kahraman et al., [4] studied a comparison the influence of speed against the T, BP, and BMEP for pure gasoline fuel about 35 Nm, 8 kW, and 350 kPa respectively. Yusaf et al, [5] investigated the influence of against the T and BP using gasoline and blended fuel of gasoline-ethanol, the results showed the maximum of the T and BP of 101 Nm and 45 kW respectively for pure gasoline as fuel. Arpa et al, [6] explored a comparison the influence of speed against the T, BP, and BMEP using pure gasoline and gasoline-like fuel, the results showed the maximum of the T, BP, and BMEP for pure gasoline as fuel about 94 Nm, 33 kW, and 900 kPa. Ebrahimi et al, [7] studied comparison of the influence of speed against the T using gasoline and natural gas as fuel, the results showed the maximum of the T about 104 Nm for gasoline at Ø =1. Hamada et al, [8] reported the influence of speed against the T, BP, and BMEP on a small motorcycle engine, the result showed the maximum of the T, BP, and BMEP of 36.2 Nm, 10.84 kW and 454 kPa respectively. Lawal et al, [9] experimented with the influence of speed against the T and BP, the results showed the maximum of the T and BP of 81 Nm and 33.38 kW for gasoline RON 91 as fuel. Karagoz et al, [10] investigated the influence of speed against the BP using pure gasoline and gasoline mixture with hydrogen and water injection, the results showed the maximum the BP about 25 kW for pure gasoline as fuel. Cahyono et al, [11] reported the influence of speed against the BP on a gasoline engine, the results showed the maximum of the BP about 55 kW on pure gasoline as fuel. Omojola et al, [12] studied a comparison the influence of speed against the T, BP, and BMEP using pure gasoline and gasoline-biogas blended as