1、Designation: D 4858 08An American National StandardStandard Test Method forDetermination of the Tendency of Lubricants to PromotePreignition in Two-Stroke-Cycle Gasoline Engines1This standard is issued under the fixed designation D 4858; the number immediately following the designation indicates the
2、 year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Depa
3、rtment of Defense.1. Scope1.1 This test method2evaluates the performance of lubri-cants intended for use in two-stroke-cycle spark-ignition gaso-line engines which are prone to preignition.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in
4、thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.
5、 Referenced Documents2.1 ASTM Standards:3B 152/B 152M Specification for Copper Sheet, Strip, Plate,and Rolled BarD 439 Specification for Automotive Gasoline4D 445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids (and Calculation of Dynamic Viscos-ity)D 664 Test Method forAcid Num
6、ber of Petroleum Productsby Potentiometric TitrationD 874 Test Method for Sulfated Ash from Lubricating Oilsand AdditivesD 910 Specification for Aviation GasolinesD 2270 Practice for Calculating Viscosity Index from Kine-matic Viscosity at 40 and 100CD2699 Test Method for Research Octane Number ofSp
7、ark-Ignition Engine FuelD 2700 Test Method for Motor Octane Number of Spark-Ignition Engine FuelD 2885 Test Method for Determination of Octane Numberof Spark-Ignition Engine Fuels by On-Line Direct Com-parison TechniqueD 2896 Test Method for Base Number of Petroleum Prod-ucts by Potentiometric Perch
8、loric Acid TitrationD 4857 Test Method for Determination of the Ability ofLubricants to Minimize Ring Sticking and Piston Depositsin Two-Stroke-Cycle Gasoline Engines Other Than Out-boardsD 4863 Test Method for Determination of Lubricity ofTwo-Stroke-Cycle Gasoline Engine LubricantsE 230 Specificati
9、on and Temperature-Electromotive Force(EMF) Tables for Standardized Thermocouples2.2 ANSI Standard:ANSI MC 96.1 American National Standard for Tempera-ture Measurement Thermocouples53. Terminology3.1 Definitions:3.1.1 combustion chamberin reciprocating internal com-bustion engines, the volume bounde
10、d by the piston crown andany portion of the cylinder walls extending above the pistoncrown when in the top dead center position, and the innersurface of the cylinder head including any spark plugs andother inserted components.3.1.2 preignitionin a spark-ignition engine, ignition ofthe mixture of fue
11、l and air in the combustion chamber beforethe passage of the spark.3.1.3 scuff, scuffngin lubrication, damage caused byinstantaneous localized welding between surfaces in relativemotion that does not result in immobilization of the parts.D 48633.1.4 spark plug foulingdeposition of essentially noncon
12、-ducting material onto the electrodes of a spark plug that may,1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.B0.06 on Two-Stroke Cycle Gasoline.Current edition approved Dec. 1, 2008. Published
13、 January 2009. Originallyapproved in 1988. Last previous edition approved in 2002 as D 485802.2Until the next revision of this test method, the ASTM Test Monitoring Centerwill update changes in this test method by means of Information Letters. These canbe obtained from theASTM Test Monitoring Center
14、, 6555 PennAve., Pittsburgh, PA15206-4489. Attention: Administrator. This edition incorporates revisions in allInformation Letters through No. 013.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandard
15、s volume information, refer to the standards Document Summary page onthe ASTM website.4Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.5Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.a
16、nsi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.but will not necessarily, prevent the plug from operating.D 48573.1.5 spark plug whiskering, also spark plug bridgingadeposit of conductive material on the spark plug electrodes
17、which tends to form a bridge between them, thus shorting outthe plug. D 48573.2 Definitions of Terms Specific to This Standard:3.2.1 major preignitionpreignition that causes a tempera-ture increase of 10C or more measured at the inner surface ofthe cylinder head.3.2.2 minor preignitionpreignition th
18、at causes a tempera-ture increase of more than 7C and less than 10C measured atthe inner surface of the cylinder head.4. Summary of Test Method4.1 The test is run in a 49 cm3single-cylinder air-cooledengine operated under the conditions required by the specifi-cation against which it is being run. T
19、hese are typically 4000rpm wide open throttle (WOT) using a 20:1 ratio of gasoline tooil by volume for a minimum of 50 h. The number ofincidences of preignition, as indicated by a rapid increase incombustion chamber temperature, is recorded.NOTE 1Pass-Fail CriterionThe number of occurrences of preig
20、ni-tion during the test of a candidate oil shall not exceed that permitted by thespecification against which it is run.5. Significance and Use5.1 Two-stroke-cycle gasoline engines are generally moreprone to preignition than are four-stroke-cycle engines due tothe absence of the internal cooling that
21、 takes place during theinduction stroke of the four-stroke-cycle engines. Preignitioncan lead to major piston damage, either directly due tolocalized overheating or as the result of preignition-induceddetonation. Some lubricant additives that are widely used infour-stroke-cycle gasoline engine oils
22、are known to increasethe probability of preignition in gasoline two-stroke-cycleengines. This procedure is used to determine the tendency of anoil to induce preignition in both water-cooled and air-cooledtwo-stroke-cycle gasoline engines.6. Apparatus6.1 Test Engine and Stand:6.1.1 Test Engine Config
23、urationAYamaha CE-50 49 cm3loop-scavenged air-cooled two-stroke-cycle engine is used.6This has 40 mm bore, 39.2 mm stroke, with an aluminumpiston operating in a cast iron cylinder bore. The cylinder headis removable, with a hemispherical combustion chamber. Forthe purposes of this test the head shal
24、l be modified as specifiedin 6.3.1.1. Further details are given in Annex A1.NOTE 2The engine designation normally includes a final letterindicating the model, such as CE-50S, the model on which this test wasdeveloped. If this model is not available check the suitability for this testof available mod
25、els with the manufacturer.66.1.2 Test StandThe dynamometer shall be able to absorb2.5 kW at 4000 to 6000 rpm with an inherent torque measure-ment accuracy of 60.5 % or better, and be capable of main-taining 4000 6 30 rpm with varying power input.Adirect shaftdrive or a belt drive from the engine cra
26、nkshaft may be used.A complete test stand assembly, as shown in Fig. 1,isavailable.76.1.3 Cooling BlowerThe original internal engine fanshall be removed or have its blades machined off. A variabledelivery blower with a free flow capacity of about 34 m3/minof air is recommended. The flow from the blo
27、wer shall bedirected toward the intake side of the engine. A suitablearrangement is shown in Fig. 1.6.1.4 Fuel SystemFuel delivery pressure shall be main-tained at 19 to 21 kPa. The temperature of the fuel entering thecarburetor shall not exceed 25C, and this may require coolingin hot climates.6.2 I
28、nstrumentation:6.2.1 TachometerAn electronic tachometer accurate to625 rpm.6The sole source of supply of the apparatus known to the committee at this timeis Engineering and Service Dept., Yamaha Motor Corp., 6555 Katella Ave Cypress,CA 90630. Parts, but not complete engines, may be obtained from Yam
29、ahamotorcycle dealers. If you are aware of alternative suppliers, please provide thisinformation to ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.7Order from Southwest Research Institute, Auto
30、motive Products and EmissionsResearch Division, 6220 Culebra Rd., San Antonio, TX 782385166.FIG. 1 Test StandD48580826.2.2 Measurement of Ambient Conditions6.2.2 is writtenon the assumption that the engine draws ambient air from thetest room. If it is supplied with air from a controlled source,refer
31、ences to ambient temperature, pressure and humidityapply to the air from the controlled source.6.2.2.1 TemperatureAthermocouple or thermometer shallbe provided to read air temperature in the range 10 to 50C.6.2.2.2 Barometric PressureA barometer recording thepressure in the test room is required.6.2
32、.2.3 HumidityA hygrometer or a wet and dry bulbthermometer is also required.6.2.2.4 RecorderContinuous recording of the ambientconditions is recommended.6.2.3 CalibrationCalibrate the tachometer, ambient tem-perature, and pressure measurement devices every 90 days.The calibration standard shall be t
33、raceable to NIST.6.3 Engine and System Temperatures:6.3.1 Combustion Chamber Temperature:6.3.1.1 Modification of Cylinder HeadThe cylinder headshall be fitted with a shielded thermocouple.Athermocouple ofthe iron-constantan type meeting the requirements of ANSI91.6 Type J (summarized very briefly in
34、 Specification E 230)isrecommended, but any thermocouple capable of performingsatisfactorily under the conditions of the test can be used.8Thegeneral dimensions and machining requirements are shown inFig. 2. The through hole, in which the thermocouple is requiredto fit closely, is about 3-mm diamete
35、r, and the counterbore shallnot extend closer than 4 mm to the combustion chambersurface. The dimensions of the counterbore and thread are notcritical, being suitable to available thermocouples, but thethread diameter shall be less than 14 mm.A18 27-NPTF threadis recommended. The thermocouple shall
36、be made so that thelast 3 to 4 mm of its tip is a snug fit into the 3-mm diameterportion of the hole, and be mounted in the head so that its tipprotrudes sufficiently to allow it to be ground flush with theinternal surface of the head without penetrating the shield.When a head has been newly fitted
37、with a thermocouple, run abreak-in in accordance with 10.2 and Table 1. The thermo-couple reading normally requires about 90 min to stabilize.6.3.1.2 Shutdown ProvisionProvision shall be made forshutdown of the engine in the case of a rapid (1 min or less)combustion chamber temperature increase of 1
38、0C or more.This normally indicates an incidence of major preignition, andis required to minimize the risk of damage to the engine. Anautomatic shut down when such an increase is experienced isrecommended. At the least an alarm shall be provided tooperate after a temperature increase of 6 to 7C to al
39、lowmanual shut down by the operator if the 10C limit isexceeded.6.3.2 Exhaust TemperatureA thermocouple is required inthe exhaust elbow within about 65 mm of the cylinder exhaust8A suitable instrument is available from Omega Engineering Inc., P.O. Box4047, One Omega Dr., Stanford, CT 069070047.FIG.
40、2 Machining of Cylinder HeadTABLE 1 Break-InDuration, min RPMThrottlePositionPlugTemperature,C2 2000 6 100 Closed (idle) Record2 4000 6 5013 open 125 max2 5500 6 5013 open 125 max2 3500 6 5013 open 125 max2 4500 6 5013 open 125 (257) maxRepeat for a total of 2 cycles, or 20 min running time.Duration
41、, min RPMThrottlePositionPlugTemperature,C2 2000 6 100 Closed (idle) Record2 4000 6 5012 open 140 max2 5500 6 5012 open 140 max2 3500 6 5012 open 140 (284) max2 4500 6 5012 open 140 maxRepeat for a total of 4 cycles, or 40 min running time.Duration, min RPMThrottlePositionPlugTemperature,C2 2000 6 1
42、00 Closed (idle) Record2 4000 6 5034 open 155 max2 5500 6 5034 open 155 max2 3500 6 5034 open 155 max2 4500 6 5034 open 155 (311) maxRepeat for a total of 4 cycles, or 40 min running time.Duration, min RPMThrottlePositionPlugTemperature,C2 2000 6 100 Closed (idle) Record2 4000 6 50 WOT 170 max2 5500
43、 6 50 WOT 170 max2 3500 6 50 WOT 170 max2 4500 6 50 WOT 170 maxRepeat for a total of 2 cycles, or 20 min running time.D4858083port to monitor exhaust temperature.7The thermocouple junc-tion shall be located within 63 mm of the center of the pipe.6.3.3 Spark Plug Gasket TemperatureThe spark pluggaske
44、t may be fitted with one or two thermocouples, thenumber depending on the instrumentation used. A design thathas been found satisfactory is described in Appendix X1.96.3.4 Combustion Chamber and Spark Plug Gasket Tem-perature RecordersThese temperatures shall be recordedusing a system capable of sto
45、ring the data for later retrieval.Maximum interval between successive recordings of the com-bustion chamber temperature is 2 s.Asystem with a range from40 to 750C and an overall accuracy of 62C is suitable.6.3.5 CalibrationCalibrate the combustion chamber, ex-haust and spark plug gasket temperature
46、measurement devicesevery 90 days. The calibration standard shall be traceable toNIST.6.4 Fuel System:6.4.1 Flow MeterAny type accurate to 60.01 kg/h atabout 1 kg/h flow rate may be used. Instruments measuringmass directly are preferred. If a volumetric measurement meteris used the temperature-densit
47、y relationship shall be deter-mined over the operating range for the actual fuel-non-reference oil mixture used for use in volume-mass conversion.6.4.2 A temperature measuring device reading to at least40C to an accuracy of 61C and a pressure gauge ortransducer reading up to about 35 kPa to an accur
48、acy of 62%are required to monitor the temperature and pressure of the fuelentering the carburetor.7. Materials and Reagents7.1 Test FuelThe test fuel shall be a leaded gasolineconsisting essentially of hydrocarbons, except for conventionallead antiknock, anticorrosion, anti-icing, etc. additives inn
49、ormal concentration, and containing no non-lead metallicantiknock compounds or oxygenated blending compoundssuch as alcohols or ethers. It shall contain 0.4 to 0.6 g/L of leadas lead alkyls with conventional motor mix or aviation mixscavengers, and shall have a minimum motor octane number of83, a maximum sensitivity (research octane number minusmotor number) of 12 as determined by Test Methods D 2699,D 2700,orD 2885, as applicable, and shall otherwise meet therequirements of Specification D 439 volatility grade A or B.Av
