10. Procedure
10.1 Engine Break-in and Silicon Passivation:
10.1.1 Following the engine assembly, install the engine on the stand and connect the engine to the stand support system.
10.1.2 Carry out the engine break-in as described in Annex A12.
10.1.2.1 Shutdown During Break-in - If a shutdown occurs during the break-in, resume the break-in from the point at which the shutdown occurred. Record such an occurrence in "Other Comments" on the appropriate report form.
NOTE 6 - Use the break-in as an opportunity to confirm engine performance and to make repairs prior to the start of the 50 h test procedure.
10.1.3 After completion of the engine break-in, shut the engine down, using the normal shutdown procedure described in 10.3.1.
10.1.4 Drain the oil and remove the oil filter.
NOTE 7 - After the engine has performed the break-in, it can be transferred to the stand equipped with the aeration measurement system and instrumented according to this procedure. Alternatively, both the break-in and the aeration testing can be carried out on the same stand provided as it can meet the break-in procedure conditions and can also maintain the operation conditions defined in this procedure for aeration testing.
10.2 Aeration Pretest Procedure:
10.2.1 Install a new Caterpillar 1R-1808 oil filter.
10.2.2 Charge the engine with 32.2 L +/- 0.2 L of test oil.
10.2.2.1 Use the pressurized, oil-fill system described in 6.3.8 or charge manually through the engine-oil, add-tube.
10.2.3 Warmup - Start the engine and perform the warmup described by Steps 1 and 2 of Table 3. After completion of Step 2, perform a 2 min cool-down at Step 1 conditions before shutting down the engine.
10.2.4 Drain the engine of the initial oil charge while allowing the oil sampling circuit pump to run and drain.
10.2.5 Repeat 10.2.2 to 10.2.4.
10.2.5.1 Install a new Caterpillar 1R-1808 oil filter.
10.2.5.2 Charge the engine with 36 L +/- 0.2 L of test oil and perform the warmup as described in Table 3 before continuing to on-test conditions as described in 10.5.
10.3 Shutdowns and Maintenance - The test may be shut-down at the discretion of the laboratory to perform repairs. However, the intent of this test method is to conduct the 50 h test procedure without shutdowns. Shutdowns between 30 h and 50 h test time invalidate the test. This period is critical for accurate measurement of the aeration average from 40 h to 50 h.
10.3.1 Normal Shutdown - A normal shutdown is accomplished by ramping down to warmup Step 1 conditions (Table 3), running for 2 min, and then stopping the engine.
10.3.2 Emergency Shutdown - An emergency shutdown occurs when the normal shutdown cannot be completed, such as under an alarm condition. During an emergency shutdown ignition can be turned off immediately and the engine allowed to stop. Such an occurrence is described in "Other Comments" of the appropriate report form (see 12.1).
10.3.3 Maintenance - Engine components or stand support equipment or both may be repaired or replaced at the discretion of the laboratory and in accordance with this test method. It is recommended to monitor the condition of the oil pressure regulator springs within the oil filter housing. These springs may require replacement if the oil gallery pressures are not typical.
10.3.4 Downtime - The limit for total downtime is not specified. Record on the appropriate report form all shutdowns, pertinent actions, and total downtime during the 50 h test procedure. Downtime is calculated as the period between the engine leaving on-test and until it returns to on-test. Warmup periods are included in the downtime period.
10.3.5 Engine Restarting - Each time the engine is restarted, perform the warmup described in 10.2.3 before proceeding onto test.
10.4 Determination of Baseline Densities:
10.4.1 General - The percent aeration of the test oil is based on a comparison of the densities of the fresh, un-aerated oil and the aerated oil sampled during the engine operation (see 11.1). To eliminate the effects of temperature on the density results, all densities are calculated at a reference temperature of 90 °C. For this purpose, the temperature dependence of the density of the un-aerated fresh oil is determined by Test Method D4052 and is used to calculate the density at 90 °C of the both the un-aerated fresh oil and the aerated sample oil. The D4052 density of the un-aerated fresh oil and its temperature dependence are referred to as baseline (BL) values and are determined after completion of the pretest procedure described in 10.2 and before carrying out the 50 h test procedure described in 10.5.
10.4.2 Baseline D4052 Density of Unaerated Fresh Oil and its Temperature Dependence:
10.4.2.1 Measure the density of the fresh test oil between 30 °C to 90 °C at 10 °C increments using Test Method D4052.
10.4.2.2 Use these seven data points to calculate the first order, linear regression of density versus temperature using the least squares method. R(2) values shall be greater than 0.99990. Repeat the density measurements as necessary until the required value is obtained.
10.4.2.3 The slope of this line quantifies the effect of temperature on the D4052 density of the fresh, un-aerated oil and is denoted by
ρBL; the intercept at 90 °C is the D4052 density of the un-aerated fresh oil at 90 °C and is denoted by ρBL,90. (Here ρ and T are used as the symbols for density and temperature, respectively, and BL denotes "baseline".)NOTE 8 - For convenience, a list of the quantity symbols and their definitions is given in 3.4.
10.5 50 h Test Procedure:
10.5.1 Following on from 10.2.5, measure out 36 L +/- 0.2 L of test oil and determine the mass. Record the volume and mass of the oil. Charge the engine as described in 10.2.2.1.
10.5.2 Start the engine and carry out the warmup described in 10.2.3.
10.5.3 Immediately after completing the warmup and without shutting down the engine, start the 50 h test procedure described in Table 4.
10.5.3.1 Test Timer - The 50 h test timer starts immediately following the warmup. If a shutdown occurs, stop the test timer immediately at the initiation of the shutdown. The test timer shall resume after the warmup described in Table 3 and when the test has been returned to the test operation schedule and all controlled quantities are within specification requirements.
10.5.4 Operational Data Acquisition - Record all operational quantities shown in Table 4 with automated data acquisition at a minimum frequency of once every 30 s. Recorded values shall have a minimum resolution in accordance with Annex A8.
10.5.4.1 Record the operational data on the appropriate test report form.
10.5.5 Oil Sampling and Analyses:
10.5.5.1 New Oil Sample - Take a 240 mL sample of the fresh test oil from the original oil container. Measure and report the quantities shown A14.2.
10.5.5.2 Take oil samples and carry out analyses according to the schedule and methods shown in Annex A13.
10.5.5.3 Record the results on the appropriate test report form.
10.5.6 Quantities for Aerated Oil Samples:
10.5.6.1 General - Measure the sample oil temperature, pressure, flow rate, and FDM density using the aeration system shown in Fig. A7.1.
10.5.6.2 Temperature of Sampled Oil - Record the average of the inlet and outlet thermocouple temperatures of the FDM. This temperature is a theoretical temperature at the midpoint of the FDM; it is referred to as the sample oil temperature and is denoted by TSAMPLE.
10.5.6.3 Pressure of Sampled Oil - Record the average of the inlet and outlet pressure transducers of the FDM. This pressure is a theoretical pressure at the midpoint of the FDM; it is referred to as the sample oil pressure and is denoted by PSAMPLE.
10.5.6.4 FDM Density ofSampled Oil - Record the sample oil density. This is the density of the aerated oil at the temperature TSAMPLE and the pressure PSAMPLE ; it is denoted by ρSAMPLE.
10.5.7 After completion of the 50 h test perform a normal shutdown as described in 10.3.1.
10.5.8 Drain the test oil charge from the engine with the oil sample circuit pump running, weigh the drained oil and calculate the total oil consumed during the test as the difference in mass between the initial charge (as recorded in 10.5.1) and the drained oil.
11. Calculation
11.1 Oil Aeration Calculations:
11.1.1 Calculate the percent oil aeration from the quantities recorded in 10.5.6 as follows:
11.1.1.1 First, using Eq 2, calculate ρSAMPLE_90, the FDM density of the aerated-oil sample at 90 °C:
where:
ρSAMPLE = the recorded density of the aerated oil sample at the temperature TSAMPLE (see 10.5.6.4),
TSAMPLE = the sample oil temperature (see 10.5.6.2), and
ρBL = the temperature dependence of the baseline density (see 10.4.2.3).11.1.1.2 Then, using Eq 3, calculate the air density, ρAIR, at the temperature and pressure, TSAMPLE and pressure PSAMPLE, respectively, of the oil sample:
ρAIR = ρSAMPLE/[287.003 x (TSAMPLE + 273.15)]
where:
ρSAMPLE = the pressure of the sampled oil determined as described in 10.5.6.3,
273.15 = the ice point in °C and,
287.003 = the specific gas constant for dry air with units Jkg(-1)K(-1), where K is the symbol for kelvin.
11.1.1.3 Finally, using Eq 4, calculate the oil aeration:
OA = [(ρBL,90 - ρSAMPLE,90)/(ρSAMPLE,90 - ρAIR)] x 100 %
where:
OA = the symbol denoting oil aeration,
ρBL,90 = the D4052 baseline density of the unaerated fresh oil at 90 °C (see 10.4.2.3), and
ρSAMPLE,90 and ρAIR are given by Eq 2 and Eq 3, respectively.
11.1.2 Calculate the average oil aeration from 40 h to 50 h by taking the average of all values calculated in 11.1.1.3 from test hours 40 through 50. Report on the appropriate test report form. Report the percent oil aeration to two decimal places.