ASTM D6593 test method for evaluation of automotive engine oils
ASTM D6593 standard test method for Evaluation of Automotive Engine Oils for Inhibition of Deposit Formation in a Spark-Ignition Internal Combustion Engine Fueled with Gasoline and Operated Under Low-Temperature, Light-Duty Conditions
8. Engine Fluids-Supply/Discharge Systems
8.1 Intake Air - Condition the intake air to 30 more or less 0.5°C, 11.4 more or less 0.8 g/kg humidity, and pressurized to 0.05 more or less 0.02 kPa.
8.1.1 Capacity - The supply system shall be capable of delivering 110 L/s of conditioned air, while maintaining the intake/air parameters detailed in Table 2. The test stand intake air duct system is shown in Fig. 2.
8.1.2 Dew Point - The dew point may be measured in the main system duct or at the test stand. If the dew point is measured in the main system duct, verify the dew point periodically at the test stand. Maintain the duct surface temperature above the dew point temperature at all points downstream of the humidity measurement point to prevent condensation and loss of humidity level.
8.2 Fuel and Fuel System:
8.2.1 System Description - A schematic diagram of a typical fuel supply system is shown in Fig. 1. Supply an excess volume of fuel to the fuel rail at all times. Introduce make-up fuel (fuel used by the engine) into the loop from an external source. Mix the make-up fuel with fuel that is returned from the fuel rail (fuel not used by the engine). Pump the fuel through a mixing chamber, or small heat exchanger, which is used to mix the two streams and provide fuel of consistent temperature to the engine. Deliver the fuel to a high-pressure pump (Ford P/N E7TF-9C407 or E7TC-9C407), that boosts the pressure and supplies the fuel to the fuel rail.
8.2.2 Controls - Maintain the fuel temperature to the fuel rail below 50°C. To ensure good atomization of the fuel, maintain the fuel pressure to the fuel rail above 185 kPa. In addition, the fuel pressure should be constant at all steady-state conditions to ensure good speed, power, and air-fuel ratio control.
8.2.3 Fuel Volume Required - Approximately 3300 L of sequence VG unleaded gasoline are required for each test.
8.2.4 Fuel Batch Approval Process - Obtain fuel from the supplier listed in X2.1.5. Each new batch of fuel is approved by the following process:
8.2.4.1 Before initial blending, typical samples of the fuel blend components are analyzed, and the data are compared with predetermined physical specifications. A small amount of fuel mixture is then blended, analyzed, and compared to predetermined specifications. The ASTM Testing Monitoring Center (TMC) confirms the acceptability of the fuel mixture analytical data and authorizes blending of the entire batch for engine testing. After the entire batch is blended, the TMC confirms the acceptability of the analytical data of the entire fuel batch, and authorizes the engine test fuel approval program.
8.2.4.2 A sample of the fuel is shipped to two designated independent laboratories. A designed program involving more than one calibration test is completed using reference oils selected by the TMC. (The Sequence V Reference Oils and Fuels Sub Panel, ASTM D02.B0.01.05, is involved in the design of the program.) The TMC reviews the test results and if acceptable, authorizes the fuel supplier to notify potential purchasers of the approval status of the fuel batch.
8.2.5 Fuel Batch Analysis - Upon receipt from the supplier, it is the responsibility of the laboratory to analyze each fuel shipment to determine the value of the parameters shown in Table 3 (except sulfur, oxidation stability, and distillation). Compare the results to the values obtained by the supplier on that particular batch. The results should be within the specification band shown in Table 3 beside each parameter. This provides a method to determine if the fuel batch is contaminated or has aged prematurely. If any results fall outside the tolerances shown in Table 3, the laboratory should contact the TMC for help in resolving the problem. One potential method for resolving the problem is to obtain an analysis at the fuel supplier's laboratory of the as received fuel sample.
8.2.6 Laboratory Storage Tank Fuel Analysis - Analyze the contents of each fuel storage tank that contains fuel used for calibrated Sequence VG tests bimonthly. Analyze fuel in run tanks, those with a direct feed line to test engines, every month. Laboratories should take composite samples using Table 1 in Practice D4057, as a guideline. The fuel supplier shall have the capability to analyze the fuel samples using the test methods specified in Table 3 and this section. The fuel supplier shall provide an adequate supply of fuel sample containers with packaging and pre-addressed return labels to each Sequence VG laboratory. Upon receipt of all fuel samples required in 8.2.6 from the laboratories, the fuel supplier shall perform the following analyses, report the results to the submitting laboratory, and tabulate the results in a database.
Reid vapor pressure (Test Method D323)
API gravity (Test Method D287 or D1298)
Distillation (Test Method D86)
Lead (Test Method D3237 or D5059)
Washed gums (Test Method D381)
Unwashed gums (Test Method D381)
8.2.6.1 When results from the physical and chemical tests listed above appear to differ significantly from the expected results, analyze a second sample, or conduct the following tests, or do both:
Hydrocarbon speciation (Test Method D2789)
Oxidation stability (Test Method D525)
Potential gums (Test Method D873)
8.2.6.2 The fuel supplier shall also issue a bimonthly analysis of the fuel from the main storage tank, which should represent normal aging. The analysis shall include the parameters in Table 3.
8.2.6.3 Forward the results of the analyses performed in 8.2.6 and 8.2.6.1 to the TMC for inclusion in the appropriate data base.
8.2.7 Fuel Batch Shipment and Storage - Ship the fuel in containers with the minimum allowable venting as dictated by all safety and environmental regulations, especially when shipment times are anticipated to be longer than one week. Store the fuel following all applicable safety and environmental regulations.
8.3 Engine Oil and Engine Oil System:
8.3.1 Test Oil Description:
8.3.1.1 The test oil sample shall be uncontaminated and representative of the lubricant formulation being evaluated.
8.3.1.2 A minimum of 7.5 L of new oil is required to complete the test. A 20 L sample of new oil is normally provided to allow for inadvertent losses.
8.3.2 System Description:
8.3.2.1 Configure the oil system as shown in Fig. A3.8 to minimize stand-to-stand variations that could influence test severity. Measure engine oil pressure at the points shown in Fig. 5. The oil flow rate and external pressure drop are controlled by specifying the volume, plumbing conflguration, and orientation of the heat exchanger. The oil flow out of the vertically mounted heat exchanger shall be level with the oil-in thermocouple. The lengths of the lines are not specified although the line diameters are indicated in Fig. A3.8. The line length and diameter have a large influence on the volume of the external system. The internal volume of the entire external system shall be 540 more or less 30 mL.
8.3.2.2 Use oil filter adapter OHT6A-0007-1 (X2.1.11), oil filter OHT6A-012-2 (X2.1.11). Be sure all hoses and fittings on the oil heat exchanger are properly connected and secure. The external oil system components shall not be brass, copper or galvanized, as these metals may influence used oil analysis.
8.3.3 Heat Exchanger - The heat exchanger has been chosen to minimize the volume of the external system. The heat exchanger has adequate but not excessive capacity to control the oil temperature. The system requires a high level of maintenance to provide adequate cooling, especially when process water temperature is high. An effective, well-maintained process water control system is necessary to achieve the specified oil temperatures. Use vertically mounted ITT heat exchanger P/N 5-160-02-008-002 (X2.1.9). Configure the system to allow the process water to flow through the vertical tubes and the oil through the shell. This orientation will facilitate cleaning of the tubes.
8.3.4 System Cleaning:
8.3.4.1 Clean the external oil cooling system thoroughly before each test. An acceptable technique for cleaning the oil heat exchanger is detailed in Annex A6. Flush and rinse the external lines before each test. The specific technique used (removed from or flushed on the stand, and so forth) is left to the discretion of the laboratory.
8.3.4.2 Regardless of the flushing technique employed, use an organic solvent (see 7.7.3) for the final flushing followed by separate rinses with hot (> 60°C) water and aliphatic naphtha (7.7.1) before air-drying the components. (Warning - Incomplete cleaning of the external oil system may allow debris to dislodge and circulate throughout the engine during subsequent tests. Incomplete cleaning may also cause oil temperature control problems and contaminate subsequent test oils.)
8.3.5 Control Specifications - The operating conditions are specified in Table 2. Additional information concerning the oil pressure, is found in 12.5.7. Cyclic ramping specifications are detailed in Table 4.
8.4 Coolants:
8.4.1 Description - The engine coolant is equal parts of demineralized (less than 0.34 g/kg) or distilled water and a fully formulated ethylene glycol based automotive antifreeze to protect against corrosion of all system components. The RAC coolant is a solution of demineralized (less than 0.34 g/kg) or distilled water and an additive treatment of 475 mL of Pencool 2000 per 15 L of water.
8.4.2 General System Description - The following guidelines are common to both the engine and RAC coolant systems:
8.4.2.1 A transparent section is required to permit visual inspection of the coolant. Provide air bleeds to allow removal of entrained air. Provide a drain at the low point of the system to allow complete draining of the system.
8.4.2.2 An effective, well-maintained process water control system is necessary to achieve the specified coolant temperatures.
8.4.2.3 The system shall allow precise calibration of the flowmeters, after installation in the test stand. Avoid turbulence near the measurement meters, and the flowmeters used for calibration.
8.4.3 Engine Coolant System Description:
8.4.3.1 Configure the engine cooling system according to the schematic diagram shown in Fig. A3.18. The engine coolant system volume shall be 24 more or less 2 L. This volume includes all equipment, plumbing, and the engine excluding the coolant reservoir and plumbing connecting the coolant reservoir with the main system (see Fig. A3.18) The coolant reservoir volume shall be 9.0 more or less 2 L. The thermostat housing is modified to accept the coolant outlet temperature thermocouple (9.1.3). Do not install the thermostat. Block coolant bypass port in intake manifold (7.6.2.1). Inspect the water pump drive belt for defects before installation.
8.4.3.2 A radiator cap is used to limit system pressure to 105 kPa. Pressurize the coolant system to 70 more or less 10 kPa at the top of the coolant reservoir (Fig. A3.18).
8.4.3.3 The engine coolant flow rate and outlet temperature are controlled in accordance with the specifications listed in Table 2. Information concerning the cooling flow rate measurement device is detailed in 9.3.2. Cyclic ramping specifications are detailed in Table 4. The coolant flow rate is measured with a venturi flowmeter (X2.1.6) and controlled with an in-line flow control valve.
8.4.3.4 Modify the engine coolant temperature sensor to deliver the correct signal to the EEC during the start of Stage III. Attach a relay and resistor as shown in Fig. A3.14 between the ECT sensor and EEC module.
8.4.3.5 As a minimum, inspect and clean the engine coolant system components, external to the engine, prior to running each reference calibration test. A specific flushing technique is not specified. However, the technique should employ a commercial descaling cleaner (7.7.3).
8.4.4 RAC Coolant System Description:
8.4.4.1 Inspect and clean the complete RAC control system prior to running each reference oil calibration test. A specific flushing technique is not specified. However, the technique should employ a commercial descaling cleaner (7.7.3).
8.4.4.2 Schematic diagrams of the RAC coolant control systems are shown in Fig. 6. Derive heat for the control system from an external source, such as hot water, steam, or an electric immersion heater.
8.4.4.3 Control the RAC coolant flow rate and inlet temperature in accordance with the specifications listed in Table 2. The coolant pressure is not specified, but design the system to minimize the pressure on the RAC and prevent distortion of the jacket. (Warning - Maintain the system pressure below 70 kPa (10 psig) to prevent distortion of the RAC jacket.)
8.5 Cyclic ramping specifications are detailed in Table 4.
