ABSTRACT
The performance of the oils selected in this work was tested for considering Viscosity, Viscosity Index, Density, Flash Point, Pour Point, and Carbon Residue. The most important of all the properties which makes the oil protect against wear is viscosity that helps to reduce friction between moving parts in the engine. The Viscosities of the oils; Oando SAE 20W50, Total SAE 20W50, Mobil 1 SAE 0W40, Total SAE 40, and AZ SAE 20W50 at 24.8°C (room temperature) and 100°C (maximum test temperature) are 290 cSt and 18 cSt, 290.5 cSt and 20 cSt, 286.4 cSt and 21.20 cSt, 295.2 cSt and 15.60 cSt, 296.8 cSt and 19.60 cSt respectively. This implies that the Mobil 1 is most preferred as it has the least change in viscosity with respect to change in temperature and Total SAE40, a monograde oil as the least preferred as it has highest change in viscosity with respect to change in temperature when high temperature is expected in the service environment. The pour points of the oils are -240C, -22 0C, -280C, -150C, and -220C respectively. Based on this, all the oils are suitable for use in internal combustion engine in Nigeria and Africa. However, in an environment where very low temperature is expected during winter, the Mobil 1 (synthetic Oil) is most preferred and the monograde Oil is not suitable as the flowability may not be good enough at engine start up. The flash point of the Oils is 175 0C, 160 0C, 160 0C, 102 0C, and 170 0C respectively. These Oils are suitable for use in internal combustion engine as all the flash points are above the expected temperatures (0C) during a normal working condition. The carbon residue found in the Oils was 0.95 %, 0.90 %, 0.60 %, 1.00 %, and 0.95 % respectively. The Synthetic Oil has the lowest carbon residue and the monagrade Oil has the highest carbon residue, and so the synthetic Oil is most preferred based on carbon residue result since high amount of carbon residue is a disadvantage. In all the results of laboratory test, all the Oils were seen to be suitable in internal combustion engine with the most preferred Oil as the synthetic followed by the multigrade and the least performing oil is the monograde. To carry out Pressure Mapping Experiment in this work, a pressure mapping equipment was developed. An Internal Combustion Engine, Thermocouple, Tachometer and Pressure Tube were obtained from the market and integrate together to function as desired based on the theoretical background of pressure mapping. The pressure mapping experiment is a fast method of measuring the performance of the lubricating Oil by mapping the pressure of the Oils in an internal combustion engine. This Oil pressure mapping is recommended for the evaluation of the performance properties of the Oils in our local market.
CHAPTER ONE
1.0 INTRODUCTION
1.1 Preamble
From time immemorial, liquids, including water, have been used as lubricants to reduce
friction and wear and remove heat between two surfaces in contact. At present, lubricating oil also called lube oil is the most commonly used lubricant because it has found a wide range of application in the field of engineering.
A lubricant, sometimes called lube, is a substance (often a liquid) which is introduced between two surfaces in contact moving relative to each order to keep them separate under all loads, temperatures and speed thus minimizing friction and wear. The substance may act as cooling fluid removing heat from the system and also protect surfaces from the attack of aggressive products formed during the operation. Lubricants may also perform the function of dissolving and transporting foreign particles (http://www.Weareoil
.com/technical_properties_of_lubricant.htm)
Majorly, there are solid and liquid lubricants. Air and other gas based lubricants are there, but for the purpose of this research work, consideration is limited to liquid lubricants. Examples of liquid lubricants are: mineral oils, vegetable oils and synthetic oils.
The most common liquid lubricants are the mineral oils. This is because of the supply of crude oil. The term mineral oil is used here to mean lubricating base oil derived from crude oil that is refined from naturally occurring petroleum. Since they are commonly used, important information about their properties is now available.