1、Designation: D 2758 94 (Reapproved 2003)Standard Test Method forEngine Coolants by Engine Dynamometer1This standard is issued under the fixed designation D 2758; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a full-scale clean engine testdesigned to evaluate corrosion protection and inhibitor stabilityof engi
3、ne coolants under simulated heavy-duty driving condi-tions.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is ther
4、esponsibility 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. Specific hazardsstatements are given in Section 6.2. Referenced Documents2.1 ASTM Standards:D 1121 Test Method for Reserve Alkalin
5、ity of EngineCoolants and Antirusts2D 1287 Test Method for pH of Engine Coolants and Anti-rusts2D 1384 Test Method for Corrosion Test for Engine Coolantsin Glassware2G 1 Practice for Preparing, Cleaning, and Evaluating Cor-rosion Test Specimens32.2 Federal Standard:4CFR Title 29 OSHA Regulations3. S
6、ummary of Test Method3.1 This test method involves the operation of a standardpassenger car engine on a dynamometer stand under constantspeed, load, and coolant temperature conditions for a total of700 h. The performance of the coolant is judged by examina-tion of (1) coolant samples, (2) metal corr
7、osion specimens, and( 3) cooling system components.4. Significance and Use4.1 This test method provides a laboratory technique ca-pable of reproducing the complex environmental stresses acoolant encounters under actual engine operating conditions.The test method provides improved discrimination over
8、 glass-ware and simulated service tests and improved correlation withfield service. Although the test method is particularly valuablefor developing coolants for increased service requirements, itremains that field testing is necessary to evaluate coolantperformance completely.5. Apparatus5.1 Test En
9、gine The test engine shall be a volumeproduction passenger car engine of cast iron or aluminumconstruction. Engine speed and brake horsepower should becalculated and adjusted to be equivalent to a 96.5 km/h (60mph) level road load. Aluminum accessories, such as coolantpump and timing chain cover, ar
10、e optional. The engine shall beequipped with a matching radiator and pressure cap. A coolantoverflow reservoir and closed-system pressure cap are op-tional, except when specified by the manufacturer. Assemblethe test components to provide a complete cooling system. Therelative positioning of the rad
11、iator and engine should duplicate,as closely as practicable, the mounting in the automobile withthe fan omitted. All radiator hose lengths should be held to aminimum. The radiator shall be cooled by forced air.5.2 Instrumentation and Control (See Fig. 1)Run theengine on a test stand coupled to an en
12、gine dynamometer withappropriate accessories for control of the designated operatingconditions. Measure engine coolant temperature out of theengine at a point immediately adjacent to the coolant outlet.Measure manifold vacuum, oil pressure, and exhaust pressureat appropriate points and monitor them
13、throughout the test inorder to ensure proper engine performance. Install a pressuregage in the outlet tank of a crossflow radiator or the top tank ofa downflow radiator to read the gage pressure.5.3 Corrosion Measurements:5.3.1 Evaluate corrosion protection using metal specimens.The specimen arrange
14、ment shall be basically that used in TestMethod D 1384. The specimen bundle is shown in Fig. 2.Preparation, cleaning, and weighing of the metal specimens aredescribed in Test Method D 1384 and Practice G 1. Eachspecimen bundle shall be held in a canvas-reinforced phenolic1This test method is under t
15、he jurisdiction of ASTM Committee D15 on EngineCoolants and is the direct responsibility of Subcommittee D15.10 on Dynamometerand Road Tests.Current edition approved Dec. 15, 1994. Published February 1995. Originallypublished as D 2758 68 T. Last previous edition D 2758 86 (1991)e1.2Annual Book of A
16、STM Standards, Vol 15.05.3Annual Book of ASTM Standards, Vol 03.02.4Available from the Occupational Safety and Health Administration, 200Constitution Ave., N.W., Washington, DC 20008.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.tu
17、be (see Fig. 3) which, in turn, is contained in a capsule. Usetwo types of specimen capsules: full-flow and bypass. Installthe full-flow capsule in the upper radiator hose, and connect thebypass capsule across the heater taps of the engine. Details ofthe capsules are shown in Fig. 4 and Fig. 5. The
18、full-flowcapsule shall contain three sets of specimens; weigh andreplace one set with a fresh set at 100-h increments, and weightwo sets at the conclusion of the test. The bypass capsule shallcontain three sets of specimens; clean, weigh, and replace thefirst set at 100-h increments. Clean and weigh
19、 the second set at400 h. Replace, clean, and weigh this set at the end of the test.Clean and weigh the third set at the end of the test.5.3.2 Position the full-flow capsule in the upper radiatorhose at a point below the radiator coolant level.5.3.3 The bypass capsule should be located in close prox-
20、imity to the engine in order to avoid excessive coolanttemperature drop.5.3.4 Equip the bypass capsule with a temperature-measuring device to assure that normal flow is being main-tained. (A temperature drop from normal operating temperatureindicates an obstruction in the bypass circuit.) A mounting
21、bracket attached to the radiator stand is recommended. Mountthe capsule below the radiator coolant level in a verticalposition. Connect the bottom fitting of the capsule with arubber hose to the standard heater supply nipple, and connectthe top fitting to the return nipple on the coolant pump.5.4 Fu
22、el and Crankcase OilBecause of the extendedduration of this test, it is suggested that high-quality fuels andmotor oils be selected to control combustion problems andachieve maximum valve life.6. Precautions6.1 Safety Precautions:6.1.1 CoolantAll coolant concentrates and their solutionsshould be con
23、sidered harmful or fatal if swallowed.6.1.2 Specimen CleaningWhen cleaning aluminum speci-mens with chromic acid/orthophosphoric acid solution, usefume hood.6.1.3 Personal ProtectionAppropriate personal protectionequipment (safety glasses, gloves, etc.) should be worn at alltimes when working with h
24、ot, pressurized engine systems. Ingeneral, engine speed should be lowered to 1000 rpm at noload, and the temperature and pressure on the cooling systemshould be lowered to a level below the boiling point of thecoolant before approaching the engine. To avoid possibleburns, care should be exercised in
25、 venting and opening theradiator pressure cap.6.1.4 Safety Guards Sturdy safety guards must be usedfor the fan belt, pulleys, couplings, and drive shaft (see OSHARegulations, CFR Title 29).FIG. 1 Air Cooling SetupD 2758 94 (2003)26.1.5 Maintenance of Physical EquipmentIn the operationand planning of
26、 the dynamometer test facility, adequate fore-thought must be given to the fuel system, exhaust system, firehazards, and general housekeeping in order to maintain a highNOTE 1AAlternate specimen bundles are shown in Test Method D 1384.Metric Equivalentsin. 0.0601161831614176471612 12mm 1.52 1.59 3.1
27、8 4.76 6.35 6.75 11.11 12.7 25 51FIG. 2 Corrosion Specimen BundleMetric Equivalentsin.31614716 11516 2116 212mm 4.76 6.35 11.11 49.21 52.39 63.5NOTE 1To achieve snug fit of the specimen bundle in the tube, add insulating washers as necessary under the brass nut on the specimen bundle.FIG. 3 Specimen
28、 Bundle SleeveD 2758 94 (2003)3level of safety standards. For example, checks for leaks in thefuel, oil, and exhaust systems must be made on a continuingbasis, and consideration must be given to the routing of a hotexhaust system in an area of combustible materials.7. Preparation of Apparatus7.1 Eng
29、ine Reconditioning:7.1.1 Check the engine and recondition, if necessary, priorto each test run. For each new engine, prior to a series of tests,and those engines being reconditioned for further testing,install new cylinder head gaskets; the engine manufacturersrecommendations should be followed rega
30、rding the use ofgasket sealing compounds. When no specific recommendationis made by the engine manufacturer, the cylinder head gasketsand other coolant sealing gaskets should be coated with anadhesive sealant. This will ensure against coolant and exhaustgas leakage at some advanced point in the test
31、, possiblyvoiding the test and its results. A new radiator should beinstalled before each test. The cooling system should bechecked for the following common defects: (1) cylinder headgasket leakage resulting in exhaust gas contamination of thecoolant, (2) air induction into the coolant due to a worn
32、 coolantpump seal, and (3) defective lower radiator hose connection.Methods of checking for these defects appear in Annex A1.7.1.2 Clean the engine cooling system with a chelator-typecommerical cleaner (see Annex A2). Replace all hoses after thecleaning procedure, but before each test.7.2 Installati
33、on of Test Specimens and Coolant:7.2.1 Prior to the installation of the coolant, install a newaluminum coolant outlet (if the engine is so equipped), alongwith a thermostat fixed in the full open position (see Note). Flatwashers should be used under the coolant outlet-attaching boltheads to minimize
34、 damage to the mounting flanges. Install thespecimen-containing capsules at this time.NOTE 1Thermostats of different manufacturers have different designminimum travel positions. “Full open” would mean the maximum travel.To block a thermostat open, the power element should be drilled andtapped for an
35、 adjusting screw, soldered into position and cut off. Neversolder the piston to the piston guide as this may cause damage orannealing of other thermostat components. To determine maximum travel,measure valve position equivalent to 11C (20F) above stamped openingtemperature; for example, 89C 1 11C 5
36、100C 192F 120F 5 212F!.7.2.2 Based upon careful measurement of the volume of thesystem, add a measured amount of concentrated coolantdirectly to the cooling system to provide a 40 volume %coolant solution when filled to overflow with water containingMetric Equivalentsin. 112 2214mm 38 50.8 57FIG. 4
37、Upper Radiator Hose Full Flow Specimen CapsuleMetric Equivalentsin38 214mm 9.5 57FIG. 5 By-Pass Specimen CapsuleD 2758 94 (2003)4100 ppm each of chloride, sulfate, and bicarbonate ions (seeAnnex A3). If desired, single-phase-inhibited coolant may bepremixed with corrosive water in a clean container
38、and addedto the cooling system as a solution. Under no conditionspremix external to the cooling system at the initiation of thetest two-phase coolants containing polar oils. Before startingthe test and after installing test coolant, conduct a 103-kPa(15-psi) pressure leakage test to check for extern
39、al coolantleakage at hoses, gaskets, and coolant pump.7.2.3 With the engine running at 1000 rpm no load and 93C(200F) coolant outlet temperature, drain sufficient coolant tobring the radiator level from overflow to 19 mm (34 in.) belowthe pressure cap seat for down-flow radiators, and 38 mm (112in.)
40、 below the pressure cap seat for cross-flow radiators. (Whenradiator is equipped with an overflow reservoir and closed-system pressure cap, coolant level should be at the pressure capseat.) Replace radiator cap. Save the drained coolant, and addit to 2-L (2-qt) sample of premixed 40 % test coolant a
41、ndcorrosive water solution to use as makeup throughout the test.8. Procedure8.1 Maintain the following test conditions throughout thetest method, except for the inspections detailed in subsequentsections:Coolant 40 volume % concentration of test coolantin 100-100-100 corrosive waterCoolant outlet te
42、mperature 93 6 2C (200 6 3F) or optionalExhaust pressure 0 to 25.4 mm (0 to 1 in.) HgTest duration 700 hThermostat Fixed to remain full openRadiator cap Standard specification for the engine cool-ing systemCoolant level 19 mm (34 in.) below pressure cap seat fordown-flow radiators38 mm (112 in.) bel
43、ow pressure cap seat forcross-flow radiatorsAt pressure cap seat when radiator is equip-ped with an overflow reservoir and clos-ed-system pressure capSpeed and brake hP Equivalent to 96.5 km/h (60 mph) levelroad load8.2 Perform periodic inspections throughout the test, asgiven in Table 1.9. Interpre
44、tation and Significance of Results9.1 The test method is intended to provide a more compre-hensive evaluation of coolant performance than is obtainablewith glassware and stimulated service tests. Correlation withfield service is generally good for engines of similar design andmaterial, but depends t
45、o a significant degree on the investiga-tors ability to interpret test results in relation to field serviceexperience. Field service will inherently impose variations inseverity.9.2 The individual specimen weight loss values have limitedsignificance in terms of absolute corrosion protection withresp
46、ect to field service. Instead, they must be compared tobaseline values established with coolants of known fieldservice performance. The comparative weight loss valuesencountered with those specimens that remain undisturbed forthe duration of the test indicate overall corrosion protection bythe test
47、coolant. These specimens should be the most valuableto predict field service performance. The specimens, which arereplaced at predetermined intervals, and present a clean activesurface, may be used to predict extended coolant performanceas related to inhibitor depletion and formula degradation rate.
48、A change in weight loss pattern may indicate coolant deterio-ration even though the solution characteristics and undisturbedspecimen weight losses indicate a satisfactory condition.9.3 Reserve alkalinity depletion also may be used to evalu-ate coolant service life and performance, provided properpre
49、cautions in interpretation are observed. After an initialreduction due to inhibitor reaction on cooling system surfaces,the reserve alkalinity will normally decrease gradually with testhours. Variation from this general pattern is cause for investi-gation.9.4 The clean engine dynamometer test provides coolantevaluation under the duration, heat rejection, and other envi-ronmental conditions which exist in service. Results areparticularly significant when related to a background of expe-rience accumulated in a particular engine design.
