ASTM D5862 Standard Test Method for Evaluation of Engine Oils in Two-Stroke Cycle Turbo-Supercharged 6V92TA Diesel Engine
14. Interpretation of Test Results
14.1 Parts Rating Area - Environment :
14.1.1 Ensure that the ambient atmosphere of the parts rating area is reasonably free of contaminants and the temperature maintained at 75 +/- 5°F (24 +/- 3°C).
14.1.2 Rate all engine parts under cool white fluorescent lighting with an illumination level of 350 to 500 fc (3800 - 5400 lx). Ensure that all background and adjacent surfaces are flat white.
14.2 Piston Rings:
14.2.1 Measure radial ring thickness, mm.
14.2.2 Measure end gap all rings, mm.
14.2.3 Measure percent ring collapse based on reduction of freestanding ring gap, report to nearest 25 %.
14.2.4 Measure ring weight change, g.
14.2.5 Visually rate for ring distress in demerits as follows.
14.2.5.1 Ring Face Distress - Rate the rings using the scale shown in Table 7. To obtain a numerical ring demerit, multiply the distress value by the percentage of the affected area in relation to the total ring face. Determine area of distress to the nearest 1 %. Broken rings are assumed to have a distressed area of 100 % and are therefore assigned 1.00. Report results on Form 6 (see Annex A5). (Warning - Due to extreme collapsing, rings broken near the tips may not be recognized as broken. Measurement of ring weights or outside diameter, or both, may be necessary to confirm ring breakage.)
14.3 Cylinder Liner:
14.3.1 Visually rate for liner distress (scuffing):
14.3.1.1 For rating purposes, cut the liner in half vertically along the crankshaft center line. Only the area below 30 mm (1 3/16 in.) from the top of the liner and above 12.7 mm (0.5 in.) from the top of ports is rated. The area removed by the cut is normally 1 % of the area on each side. The scuff rating of this missing area is estimated based on the rating of the adjacent areas. If the adjacent area is scuffed, the area removed by the cut is rated as scuffed and vice versa. If a liner is not cut exactly into 50 % halves, the percentage of scuffed area will be normalized to the 50 % ideal by transferring the excess scuffing on the larger section to the smaller. Scuffing, which occurs anywhere within the circumference, regardless of its vertical area, is measured in circumferential percentage. A completely scuffed liner is assigned 100 %. Scuffing is defined, for the purpose of this test method, as vertical markings that overwhelm the honing crosshatch, such that no honing crosshatch pattern is visible. No differentiation is made as to scuffing severity. Report results on Form 6 (see Annex A5).
14.3.2 Visually rate for port plugging, percent area.
14.3.2.1 Estimate the percentage of cross-sectional area of the liner ports, which is plugged by deposits. These deposits likely will be black in color and dry to wet in consistency. Estimate each port and average for each liner. When reporting liner port plugging less than 1 %, report to one decimal place, that is, 0.X %. When plugging is equal to or greater than 1 %, report to the nearest 1 %. Report results on Form 7 (see Annex A5).
14.4 Piston Pin Slipper Bushing:
Measure weight to +/- 0.001 g, record on Form 12, Fig.A5.13.
14.5 Piston Rating:
14.5.1 Identify areas of tin plate removal by scratching the surface with a sharp iron object (a nail works well). Quantify those areas as a percentage of the total piston skirt surface area. Report results on Form 6 (see Annex A5).
14.6 Rocker Arm Bushing Injector Position:
14.6.1 Measure - Measure inside diameter, mm2, record on a form similar to the one in Appendix X3 (Fig.X3.10).
14.7 Referee Rating:
14.7.1 Referee ratings are required for every calibration test. The official calibration test rating is the average of the lab and referee ratings. Conduct a referee rating by a calibrated rater at a facility other than the laboratory that conducted the test. Referee ratings cannot be performed by the same calibrated facility on two consecutive tests from any laboratory.
14.7.2 Referee ratings are optional on non-reference oil tests. Conduct a referee rating by a calibrated rater at a facility other than the laboratory that conducted the test. Referee rating are recommended when a test result is close to the passing limit of the test.
14.7.3 When utilized, report the referee rating. The final test result is the average of the laboratory rating and the referee rating.
14.7.4 Calibrated Rater - Each laboratory, on a calendar year basis, shall send a minimum of one heavy-duty diesel rater to either the task force meeting held every spring or the expanded Heavy-Duty Piston Rating Workshop held every fall. If this schedule is not suitable to a particular rater or laboratory, then make alternative arrangements as soon as possible to have the rater calibrated.
