Engine Lubricants and Lubricating SystemsHome Page: http://baen.tamu.edu/users/lepori/AGSM 201 Slides Page:

Functions of Engine OilsReduce wearReduce frictionSeal CompressionReduce noiseCool engine partsReduce rustKeep parts clean

Organizations Providing Uniform Standards for OilS.A.E.Society of Automotive EngineersA.P.I.American Petroleum InstituteA.S.T.M.American Society of Testing & MaterialsAmerican Automobile Manufacturers AssociationEngine Manufacturers AssociationI.S.O.International Standards Organizations

Properties of Motor Oils

ViscosityViscosity Index (VI)Flash PointPour PointPer cent sulfated ashPer cent zinc.

Properties of Motor Oils

ViscosityViscosity Index (VI)Flash PointPour PointPer cent sulfated ashPer cent zinc.

ViscosityMeasure of the "flowabilityKinematicDynamicProperty Resistance to flowShearing stressHigh viscosity - thick oilsToo high viscosity may not reach all partsLow viscosity thin oilToo low viscosity may not provide enough strength to keep parts from wearing

Dynamic & KinematicViscosity

Kinematic Viscosity MeasurementSaybolt ViscometerGlass capillary viscometers

Dynamic Viscosity MeasurementTypical Brookfield Viscometer

Weight of oilsCommon term identifying viscosity for oils Numbers assigned by the S.A.E.correspond to "real" viscosity, as measured by accepted techniques. These measurements are taken at specific temperatures. Oils that fall into a certain range are designated 5, 10, 20, 30, 40, 50 by the S.A.E. The W means the oil meets specifications for viscosity at 0 F and is therefore suitable for Winter use.

_______________________________________________________________| || SAE Gear Viscosity Number || ________________________________________________________ || |75W |80W |85W| 90 | 140 | || |____|_____|___|______________|________________________| ||| SAE Crank Case Viscosity Number || ____________________________ || |10| 20 | 30 | 40 | 50 | || |__|_____|____|_____|______| |______________________________________________________________2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 viscosity cSt @ 100 degrees C

Properties of Motor Oils

ViscosityViscosity Index (VI)Flash PointPour PointPer cent sulfated ashPer cent zinc.

Viscosity indexThe measure of an oil's ability to resist changes in viscosity when subjected to changes in temperature.

As temperature increases viscosity decreases.Low temperatures High viscosityHigh temperature Low viscosity

Multi-viscosity/Multi-grade Oil Oil meeting SAE requirements for both low-temperature requirements of light oil and high-temperature requirements. Also know as multiweight oil. Oil that meets certain low-temperature and high-temperature requirements simultaneously (e.g., SAE l0W-40).

Properties of Motor Oils

ViscosityViscosity Index (VI)Flash PointMinimum sample temperature at which vapor is produced at a sufficient rate to yield a combustible mixture. Pour PointThe lowest temperature at which oil will pour. Per cent sulfated ashPer cent zinc.

Properties of Motor Oils

ViscosityViscosity Index (VI)Flash PointPour PointPercent sulfated ash how much solid material is left when the oil burns.A high ash content will tend to form more sludge and deposits in the engine. Low ash content also seems to promote long valve life. Look for oils with a low ash content. Per cent zinc.

Properties of Motor OilsViscosityViscosity Index (VI)Flash PointPour PointPer cent sulfated ashPercent zinc the amount of zinc used as an extreme pressure, anti-wear additive. The zinc is only used when there is actual metal to metal contact in the engine. Hopefully the oil will do its job and this will rarely occur, but if it does, the zinc compounds react with the metal to prevent scuffing and wear. A level of 0.11% is enough to protect an automobile engine for the extended oil drain interval, under normal use.

Common motor oil additivesViscosity index improvers used to enhance the base qualities of the oil, and to keep the oil from thinning too much as heat increases. Pour-point depressantsprevent crystals from forming in extreme cold conditions, and consequently lower the oil's pour point (temperature at which it pours).

Common motor oil additivesOxidation inhibitorshelp prevent the oil from oxidizing (in other words, burning). When oil oxidizes, it loses its ability to protect the engine. It also produces sludge deposits and traps corrosive acids. Rust-corrosion inhibitorshelp prevent and neutralize water and oxygen from acid-etching the metals in the engine and forming rust particles. If this corrosion were to happen, some complex acids would form and other sludge problems would occur.

Common motor oil additivesDispersants help the oil to absorb and retain contaminants such as dirt or tiny metal particles (from engine wear) until the oil passes through the oil filter, where the contaminants are trapped. Detergentshelp to remove contaminants from the engine components and hold them in the oil until it reaches a filter, or until it is changed the next time. They don't only clean up a dirty engine.

Common motor oil additivesFriction modifiers/wear inhibitors "stick" to engine surfaces better, reducing friction and improving fuel economy. Oils with the "energy conserving" labels contain friction modifiers. Foam inhibitors (Antifoamants)prevent the oil from being whipped into many tiny air bubbles. Air bubbles don't lubricate. This also helps prevent sludge formation when the emulsion process is a possible threat in an engine.

Types of Motor OilsPetroleum BasedRefined from crude oilSupplemented with additivesSyntheticLubricants chemically engineered from pure chemicals rather than refined from crude oil. Can provide significant advantages over refined oils.Longer oil change intervalsLonger engine lifeIncrease gas mileageMore expensive

What the h___ is he talking about?Items that tell us about selecting an oil!

What the h___ is he talking about?

How to select an oil for different purposes.

What to look for on an oil container.

What Oil Should You Use

API Donut

GasolineServiceClassification

DieselEngineClassification

Lubrication SystemsSplashDipperSlingerForce Feed & SplashFull Force Feed

Splash Lubrication

Force Feed and Splash

Full Force Feed

Oil Pump

Oil pump intake screen

Engine Oil Degradation and ContaminationOil thickeningOxidationVaporization of lighter components Fuel Hydrocarbon compoundsCombustion ProductsCarbonWaterSulphur OxidesFuel chemical additivesDust and DirtMetal from wear of components

Oil Filtration Systems

By-PassFull FlowShunt

Engine Lubrication System with both by-pass and full-flow filtration

Two filters provide ability to filter smaller particles

Filter elementsSurfacePleated paperMetal screenDepthCotton waste

Changing oil and filters renews engine protectionDirty oil reduces life of an engine.Reduce maintenance and increase engine life by changing engine oil and filters on a regularly scheduled basis.Interval between changes depends on operating conditions.Oil analysis provides management of oil change intervals Recommend for fleet operations.

Oil Pressure Important SensorLow pressure light indicator

Lubrication Links on the WebMotor oils and moreMotor Oil Functions & PropertiesSelecting motor oilsAPI Starburst and DonutMotor Oil AdditivesLubrication SystemsFiltration SystemsSources of oil contaminantsFilters & filter mediaSynthetic oil base stocksSynthetic oil historyOil Analysis Example 1Example 2