1 Scope
1.1 This standard specifies the method for evaluating the thickening of automotive engine oil under high-temperature oxidation, the generation tendency of deposits such as high temperature sludge and varnish, and the antiwear performance.
1.2 This standard is applicable to performance evaluation of gasoline engine oil (such as SE and SF) and of relevant diesel engine oil.
2 Normative References
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest edition of these documents is applicable. For undated references, the latest edition of the normative document is applicable to this standard.
GB/T 258 "Determination of Acidity of Gasoline, Kerosene and Diesel Fuels"
GB/T 259 "Petroleum Products-Determination of Water-soluble Acids and Alkalis"
GB/T 260 "Determination of Water Content in Petroleum Products"
GB/T 265 "Petroleum Products-Determination of Kinematic Viscosity and Calculation of Dynamic Viscosity"
GB/T 377 "Determinations of Tetra-ethyl Lead Content"
GB/T 380 "Determination of Sulfur Content in Petroleum Products (Lamp Method)"
GB/T 511 "Petroleum Products and Additives-Determination of Mechanical Impurities-Gravimetric Method"
GB 1922 "Solvent Naphthas"
GB/T 5096 "Petroleum Products-Corrosiveness to Copper-Copper Strip Test"
GB/T 5487 "Test Method for Knock Characteristics of Motor Fuels by the Research Method"
GB/T 6536 "Petroleum Products-Determination of Distillation"
GB/T 8017 "Petroleum Products-Determination of Vapour Pressure-Reid Method"
GB/T 8018 "Gasoline-Determination of Oxidation Stability-Induction Period Method"
GB/T 8019 "Motor Gasoline and Aviation Fuels-Determination of Existent Gum-Jet Evaporation Method" (GB/T 8019-87, neq ISO 6246:1981)
GB/T 11132 "Standard Test Method for Hydrocarbon Types in Liquid Petroleum Products by Fluorescent Indicator Adsorption"
SH/T 0174 "Aromatic Hydrocarbon and Clean Oils-Qualitative Test of Thioalcohol (Doctor Test)"(SH/T 0174-92, mod ISO 5275:1979)
SH/T 0510 "Scoring Method for Gasoline Oil Engine Test"
SH/T 0513 "Test Method for Evaluation of Automotive Engine Oil for Inhibition of Oxidization and Wear under High-temperature Conditions (MS Sequence-IIID Method)"
3 Terms and Definitions
For the purposes of this standard, the following terms and definitions apply.
3.1
Blowby
Gas mixture of combustion product, unburned fuel oil and air into a crankcase from combustion chamber in engine running.
3.2
Air-fuel ratio
Mass ratio of air and fuel oil into gas mixture of engine combustion chamber.
3.3
Sludge
Deposit mainly formed by fuel combustion product, lubricating oil oxygen product and water, which is incapable of flowing down from engine parts but may be wiped off with cloth.
3.4
Varnish
A deposit which is hard and dry and insoluble to oil, has luster, cannot be wiped off with soft cloth, but may be washed off with some solvent.
3.5
Debris
Solid pollutant or wear debris inducted into engine non-artificially.
3.6
Free piston ring
When piston rotates from vertical position to horizontal position, piston ring falls into a ring groove by virtue of its gravity or slight finger pressure.
3.7
Sluggish piston ring
Piston ring is incapable of moving freely in a ring groove, but may be pressed in or out of ring groove through medium finger pressure, without rebound phenomenon.
3.8
Stuck piston ring
Partial or complete piston ring is blocked in a ring groove and is incapable of being moved through medium finger force. Stuck piston ring is divided into cold stuck piston ring and hot stuck piston ring. Cold stuck piston ring is that the piston ring is free in engine running but sticks when piston and piston ring are cooled to the room temperature, and its characteristic is that there is continuous polishing surface on the full circumference of piston ring and cylinder wall contact surface; hot stuck piston ring is that the piston ring sticks in piston ring and its characteristic is that some part of piston ring and cylinder wall contact surface has varnish or carbon deposit.
3.9
Oxidization
Phenomenon that automotive engine oil thickens and generates such deposits as sludge and varnish under high-temperature conditions due to chemical or mechanical action.
3.10
Reference oil
Lubricating oil that its performance characteristic is known, used for comparison.
3.11
Rust
Oxidized product of engine iron parts under humid condition and chemical action, including iron complex which is not wiped off with organic solvent.
3.12
Scoring
A severe wear type, which is characterized that its sliding direction has severe scoring or groove.
3.13
Scuffing
Part surface roughening due to such factors as metal and metal contact or extraneous debris. It is characterized that there is scratch or metal spraying phenomenon on one or two surfaces with relative motion.
3.14
Wear
Displacement or loss of material on parts surface with relative motion, the result under mechanical action or chemical action or both in general.
4 Summary of Method
Prior to test, disassemble the engine, thoroughly clean the engine parts with solvent naphthas and install new engine parts according to the method requirements. Install the assembled engine to a stand with controllable rotation speed, load and other engine operation parameters. Add test oil into the engine, start the engine, conduct timing running for 10min, and adjust the ignition timing angle. After timing running, conduct 3.5h engine runin. And then conduct 64h official test by taking 8h as one cycle under high temperature and high speed conditions.
After 10min timing running and after 8h each in 64h official test, take oil sample out and analyze, and measure the kinematic viscosity of oil sample at 40℃ in each stage. Calculate the viscosity increase rate of oil sample in each stage based on the viscosity of oil sample in 10min timing running.
At the end of the test, disassemble the engine, evaluate such deposits as sludge and varnish as required, and measure the parts.
5 Significance and Use
5.1 This test method is a engine test method for evaluating engine oil thickening and antiwear performance of automotive engine oil under high temperature and high speed conditions.
5.2 The engine oil thickening mentioned in this method refers to the viscosity increase caused by high temperature oxidization of engine oil. In practical use, engine oil thickening will reduce the pumpability of the oil pump, thereby resulting in damage of each driving medium of the engine.
5.3 The scoring result of deposits indicates the deposit generation tendency in the engine, including sticking of piston ring in ring groove and sticking of tappet. Stuck piston ring will reduce the engine's compressive force and result in engine power drop. Tappet sticking will increase driving medium wear and generate noise.
5.4 This standard has a better correlation with SH/T 0513 "Test Method for Evaluation of Automotive Engine Oil for Inhibition of Oxidization and Wear under High-temperature Conditions (MS Sequence-IIID Method)".
6 Test Equipment and Environment
Foreword I
1 Scope
2 Normative References
3 Terms and Definitions
4 Summary of Method
5 Significance and Use
6 Test Equipment and Environment
7 Temperature Measurement and Thermocouple Installation Position
8 Pressure Measurement and Measuring Position
9 Test Stand System
10 Reagents and Materials
11 Preparation of Test Devices
12 Calibration of Test Stand
13 Tests
14 Test Result Evaluation and Report
Appendix A (Normative) Quality Indexes of Fuel Oil
Appendix B (Normative) Preparation of Coolant
Appendix C (Informative) Engine Assembly and Measuring Record Table
Appendix D (Informative) CEPT-III Operation Record Table
Appendix E (Informative) Score Card
Appendix F (Informative) Test Report
Appendix G (Informative) Corresponding Air-fuel Ratio of Corrected CO2 and O2 Percentage Content
