Engine Oil Jason Dearden Steven Lemos Engineering 45 Santa Rosa Junior College Spring 2009 What Is Engine Grade Oil American Petroleum Institute (API) Society of Automotive Engineers (SAE) A Brief History of Motor Oil 1846 Crude oil refining process discovered Single Grade oil Multi Grade oil Synthetic oil first sold commercially in 1970 Properties Physical Flash Point Pour Point Viscosity Chemical Basic properties Detergents Viscosity Viscosity is the measure of a fluids resistance to flow How to measure viscosity Units: Dynamic: Pa-s, Kinematic: Stokes (St) Dynamic Viscosity Kinematic Viscosity Density Viscosities of common fluids: (At 25°C) Viscosity (Pa·s) Viscosity (cPoise) acetone 3.06 × 10−4 0.306 benzene 6.04 × 10−4 0.604 3–4 × 10−3 3–4 blood (37 °C) castor oil corn syrup ethanol ethylene glycol glycerol HFO-380 0.985 985 1.3806 1380.6 1.074 × 10−3 1.074 1.61 × 10−2 16.1 1.5 1500 2.022 2022 mercury 1.526 × 10−3 1.526 methanol 5.44 × 10−4 0.544 1.863 × 10−3 1.863 1.58 × 10−4 0.158 1.945 × 10−3 1.945 nitrobenzene liquid nitrogen @ 77K propanol olive oil 0.081 81 2.3 × 108 2.3 × 1011 sulfuric acid 2.42 × 10−2 24.2 water 8.94 × 10−4 0.894 pitch Single Grade oil Viscosity Multi Grade Oil viscosity index improvers (VII) CCS=Cold Cranking Simulator=ease of engine cranking while cold MRV=Mini Rotary Viscometer=Low temperature pumpability Cold Temp SAE W viscosity grades for engine oils Grade cranking pumping 0w 3250cP at -30°C 60,000cP at -40°C 5w 3500cP at -25°C 60,000cP at -35°C 10w 3500cP at -20°C 60,000cP at -30°C 15w 3500cP at -15°C 60,000cP at -25°C 20w 4500cP at -10°C 60,000cP at -20°C 25w 6000cP at -5°C 60,000cP at -15°C Running Temp SAE viscosity grades for engine oils Grade low shear high shear 20 5.6 - 9.3 cSt at 100°C 2.6 cP at 150°C 30 9.3 - 12.5 cSt at 100°C 2.9 cP at 150°C 40a 12.5 - 16.3 cSt at 100°C 2.9 cP at 150°C 40b 12.5 - 16.3 cSt at 100°C 3.7 cP at 150°C 50 16.3 - 21.9 cSt at 100°C 3.7 cP at 150°C 60 21.9 - 26.1 cSt at 100°C 3.7 cP at 150°C a (0w-40, 5w-40, 10w-40 grades) b (15w-40, 20w-40, 25w-40, 40 grades) How Do Combustion Engines Work? A General Combustion Engines take the Linear motion of a piston and convert it into Rotation. You can see the piston moving side to side, connected to the piston is the rod, which is then connected to the Crank, which delivers your rotation to whatever you need it for. You get the piston to move by combusting fuel and air creating a high pressure forcing the piston down on the “power stroke”. An engine speed is rated in RPM (Revolutions per Minute). Crank Rod Piston Combustion Chamber Why do engines need oil Lubrication of moving parts Engines move anywhere from 2000RPM-6000RPM in Street vehicles and up to 19,000RPM + in Race Engine. Parts would not last with metal to metal contact. You need a barrier between parts to cut down friction, oil is your barrier. Cooling Oil also acts as a heatsink for the engine, and as stated above, you need oil to cut down friction, if there was no oil the heat caused from friction would be enough to destroy any engine. Cleaning Oil acts in another way, it removes dust particles that enter the engine, and some of the carbon build up in the engine. This is one of the reasons it is important to change your oil. So, what happens to an engine without oil??? Engine Seizes Parts wear out very rapidly Catastrophic failures Holes in Engine Blocks Questions?