ASTM D6201 Dynamometer Evaluation of Unleaded Spark-Ignition Engine Fuel
ASTM D6201 Standard Test Method for Dynamometer Evaluation of Unleaded Spark-Ignition Engine Fuel for Intake Valve Deposit Formation
14. Report
14.1 Final Test Report - Make the report to the organization supplying the deposit control additive, base fuel, or test fuel.
14.2 Standard Report - The standard test report shall include the sections listed below. Begin each section on a new page, and insert the sections in the order listed below. Deviations in the format are not permitted. However, additional details and data may be attached as an appendix.
14.2.1 Title page including the name of the testing laboratory, test description, run number, start of test date, end of test date, test oil, test fuel including identification of the test fuel/deposit control additive by (the name of the submitting organization and) its name or code, or both, provided by the submitting organization, a validity statement which states that the test was conducted in a valid manner, and a signature block referring to the test overseer.
14.2.2 Unscheduled shutdown summary including the test hour the engine was shut down, the amount of time the engine was shut down, and the reason the engine was shut down.
14.2.3 Intake valve deposit weight summary including new valve weights, end-of-test valve weights that have been prepared as stated in 13.1.5, and the difference between the end-of-test valve weights and the new valve weights.
14.2.4 Induction system merit rating summary including the valve tulip, intake port, and runner entrance ratings.
14.2.5 Pretest and post test measurement summary including the pretest fuel injector flow analysis, the pretest intake and exhaust valve stem-to-guide clearance measurement summary, the pretest valve seat width measurement summary, the pretest PCV valve flow rate summary, the engine compression pressure and percent leakdown check which is performed 0.6 h into the test, the post test oil consumption data, and the final engine test fuel consumption data.
14.3 Data Acquisition Summary Report - The test validation criteria report, derived from the data acquisition equipment, shall include the sections listed below:
14.3.1 Manual data acquisition summary. Report maximum, minimum, and average data of Stage 1 and Stage 2. Omit data gathered for the first 20 min after any start-up due to engine warm-up effects.
14.3.2 Automated data acquisition summary as detailed in 12.3.3. Report maximum, minimum, average, and standard deviation of Stage 1 and Stage 2. Omit data gathered for the first 20 min after any start-up due to engine warm-up effects.
14.3.3 Stage transition data summary of engine speed and manifold absolute pressure as detailed in 12.3.3.1.
14.4 Photographs of Specific Parts - Include photographs of engine parts in the following order: (Take photographs as specified in 13.2.)
14.4.1 Intake Valves-Group,
14.4.2 Intake Valve-Cylinder 1 and 2,
14.4.3 Intake Valve-Cylinder 3 and 4,
14.4.4 Intake Port and Runner-Cylinder 1 and 2, and
14.4.5 Intake Port and Runner-Cylinder 3 and 4.
15. Precision and Bias
15.1 Precision - In 1995, an interlaboratory study (ILS) using Draft 3.1 of this test method was conducted. Sixty tests were conducted by ten laboratories on four fuels. A data analysis panel was appointed by the Coordinating Research Council to analyze the intake valve deposit weight data from the ILS. The CRC Data Analysis Panel developed ASTM repeatability and reproducibility values using the ILS data base. The original test matrix consisted of eleven laboratories performing tests on the four fuels with a repeat test on each of two of the fuels for a total of six tests per laboratory. One laboratory did not participate and data from two laboratories were eliminated because of test fuel contamination. Hence, the data from these three laboratories were not included in the ILS database. With the elimination of these 18 tests, the minimum data required for the calculation of precision as stated in ASTM D02-1007 were not met. The repeatability and reproducibility statements may be negatively impacted by the reduced sample size and should, therefore, be used with caution. The TMC will be obtaining data on reference fuels for test stand certification. These data in the future will be available for reassessing the precision calculations.
15.1.1 Repeatability - The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would in the normal and correct operation of the test method exceed 287 mg only in one case in twenty.
15.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test material would exceed 317 mg only in one case in twenty.
15.2 Bias - No estimate of bias is possible as the behavior of a fuel is determined only under the specific conditions of the test and no absolute standards exist.
16. Keywords
16.1 automotive spark-ignition engine fuel; deposit control additive; deposits (in internal combustion engines); intake valve deposits
