SH/T 0646-1997 Exhaust smoke evaluation method for air-cooled two-stroke gasoline engine oils

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Card type: Test method

1. Method number / full name / English name / replacement relationship

• Standard number: SH/T 0646-1997
• Chinese name: Exhaust smoke evaluation method for air-cooled two-stroke gasoline engine oils
• English name: Lubricants test method for evaluating exhaust gas smoke of air-cooled two-stroke gasoline engine
• Replacement relationship: This standard is published for the first time (not provided in the available source whether it replaces other standards)
• Adoption relationship: Equivalent adoption of Japanese JASO M342-92 "Exhaust smoke test method for two-stroke gasoline engine lubricating oils"
• Approval/implementation: Approved by China Petrochemical Corporation 1997-07-12, implemented on 1997-12-01 (the implementation date source-text extraction in the source text is "1977-12-01", requires confirmation against the source standard (source-text extraction))

2. Scope of application and non-applicability

• Scope of application: This standard specifies the method for evaluating the smoke emission performance of air-cooled two-stroke gasoline engine lubricating oils; it is applicable to evaluating the smoke emission performance of air-cooled two-stroke gasoline engine oils (abbreviated as two-stroke oils).
• Non-applicability: No explicit non-applicability clause is provided in the available source.

3. Method principle

Under specified test conditions, by measuring the exhaust smoke of the reference oil and the test oil, the smoke index is calculated to evaluate the smoke emission performance of the test oil (Chapter 4 of the source text, Method summary).

4. Reagents and materials (purity / preparation)

• 6.1 Fuel: Use fuel having the properties in Appendix B. Since this method uses a reference oil and a test oil for comparative evaluation, for the same series of tests, the same batch of fuel must be used.
• 6.2 Reference oil and calibration oil: The reference oil is JATRE-1, and the calibration oils are JATRE-1 and JATRE-3; their main characteristics are given in Appendix C.
• 6.3 Carbon deposit cleaning agent: The formulation is given in Appendix D.
• 7.2 Preparation of mixed fuel: According to the volume ratio of fuel to two-stroke oil 10:1, separately blend the mixed fuels of the reference oil and the test oil, each in an amount of about 1L. If the two-stroke oil and fuel separate, the test cannot be conducted, and this shall be stated in the test report in Appendix E.
• 7.3 Cleaning of the mixed fuel system: Each time the mixed fuel is changed, clean the fuel tank thoroughly with the test fuel, and drain the residual oil in the fuel line, fuel pressure regulator, and carburetor. After filling the fuel tank with new mixed fuel, drain about 100mL of mixed fuel from the carburetor drain (the source text source-text extraction is "about 1 field nJ'", requires confirmation against the source standard (source-text extraction)).
• Appendix D Carbon deposit cleaning agent formulation:
  • Formulation one: soap 10g, water glass 85g, sodium carbonate 185g, potassium dichromate 1g (the source text source-text extraction is "1 fly", requires confirmation against the source standard (source-text extraction)), water 10kg (the source text source-text extraction is "1 0 tons", requires confirmation against the source standard (source-text extraction)), place the parts in the cleaning solution and boil to about 80℃ for 2~3h, then rinse clean with water (the source text source-text extraction is "such as ℃", requires confirmation against the source standard (source-text extraction)).
  • Formulation two: kerosene 2%, gasoline 8%, turpentine 17%, oleic acid 8%, ammonia water 15% (the source text source-text extraction is "coincidentally %", requires confirmation against the source standard (source-text extraction)), phenol 30%. In the first step, mix kerosene, gasoline, and turpentine to prepare the mother liquor; in the second step, mix oleic acid and phenol, then mix with ammonia water; in the third step, pour the mixture of oleic acid, phenol, and ammonia water into the mother liquor while stirring, and it is ready for use after mixing. When using, immerse the parts in the cleaning solution for 2~3h (the source text source-text extraction is "2 one 3 divination", requires confirmation against the source standard (source-text extraction)), take them out, rinse with water, and then clean with soap powder. Because the cleaning solution has a strong odor and is highly corrosive, safety must be observed during use.

5. Instruments and equipment

• 5.1 Test engine: the engine of a Suzuki SX-800R generator set; the main technical parameters are given in Appendix A.
• 5.2 Modification of the engine:
  • 5.2.1 Control of fuel inlet pressure: Remove the fuel tank from the engine, prepare a fuel pressure regulator as shown in Figure 1 to control the fuel pressure, install it in the place of the original fuel tank, and secure it with bolts.
  • 5.2.2 Modification of the muffler:
    • 5.2.2.1 Removal of glass wool: Remove the heat insulation plate on the muffler (Figure 2), open the muffler along the rivet line and the upper half-circumference weld line of the exhaust pipe (Figure 3), remove the glass wool from the muffler, retain the baffle (Figure 4), and weld the muffler back together.
    • 5.2.2.2 Addition of an auxiliary muffler: Make an auxiliary muffler as shown in Figure 5 and weld it to the tail pipe of the original muffler. During welding, the insertion depth of the muffler tail pipe is equal to the wall thickness of the auxiliary muffler.
    • 5.2.2.3 Change of exhaust pipe direction: Cut off the exhaust pipe along line A-A in Figure 6, then weld it again as shown in Figure 7.
    • 5.2.2.4 Installation of insulation layer: To eliminate residual oil in the main muffler and auxiliary muffler, an insulation layer of about 300mm×500mm×20mm must be used, which can be wrapped tightly around the main and auxiliary mufflers.
• 5.3 Electrical energy consumption device: To consume the electrical energy generated by the generator, an electrical load consumption device as shown in Figure 8 may be installed, or other energy-consuming devices may be installed, such as an energy consumer composed of 200W, 400W, 600W, 800W, 670W, 750W resistance wires.
• 5.4 Measuring instruments: All instruments used shall satisfy the measurement items shown in Table 4.
  • 5.4.1 Exhaust smoke meter: Use a full-flow light-transmission smoke meter (model LESM-2; use of other types of smoke meters requires verification and correction). The signal from the smoke meter is corrected through a parallel circuit composed of two 1000μF electrolytic capacitors and then sent to the recorder.
  • 5.4.2 Measurement recorder: Use a computer or pen recorder capable of continuous measurement and recording.
  • 5.4.3 Thermometer: Use an instrument with an accuracy of ±1℃.
  • 5.4.4 Engine tachometer: Use a tachometer with an accuracy of 10r/min (the source text source-text extraction is "1 lOr/nun", requires confirmation against the source standard (source-text extraction)).
  • 5.4.5 Fuel flow meter: Select a flow meter with a measurement range of 0~1L/h. A glass graduated cylinder may be used as the fuel flow meter, or an electronic scale with an output signal may be used to directly measure fuel consumption.
  • 5.4.6 Hygrometer: Use a hygrometer with an accuracy of ±1%.
  • 5.4.7 Barometer: Use an instrument with an accuracy of ±0.1kPa.
  • 5.4.8 Ammeter: Use an ammeter with an accuracy of ±0.01A.
• 5.5 External cooling equipment: Use a fan or blower as external cooling equipment to simultaneously cool the generator and muffler, as shown in Figure 9.
• 5.6 Exhaust system: Composed of an explosion-proof exhaust fan and piping. The air volume of the exhaust fan should be such that it does not interfere with the engine exhaust smoke.
• 5.7 Installation of temperature sensors:
  • 5.7.1 Spark plug gasket temperature: Replace the original spark plug gasket with a spark plug gasket machined from pure copper. The copper gasket thickness is 1.8–2.2mm, outer diameter 20.8–21mm, inner diameter 14.3~14.6mm. Drill two holes of diameter 1mm in the middle of the thickness along the diameter direction, then insert the two poles of the thermocouple separately and fix them by silver welding, as shown in Figure 10. The thermocouple is installed at the lower air outlet of the cooling air, as shown in Figure 11.
  • 5.7.2 Exhaust temperature: The thermocouple is installed inside the tail pipe of the auxiliary muffler and must be placed at the center position of the tail pipe, as shown in Figure 12.
• 5.8 Fuel supply system: Use high-position fuel supply, as shown in Figure 13.
• 5.9 Placement of the smoke meter: The smoke meter is installed in a place not affected by air flows other than the exhaust air. The center of the optical axis of the smoke meter must be adjusted to a position 150mm away from the auxiliary muffler and on the centerline of the exhaust smoke flow, as shown in Figure 14.

6. Recommended operating conditions

• 7.1.1 Break-in: If a new engine is used or the crank connecting rod mechanism of the engine is replaced, break-in shall first be carried out according to the conditions specified in Table 1.
  • Table 1 Break-in conditions: Mixing ratio (the source text source-text extraction is "one frequency, * 60", requires confirmation against the source standard (source-text extraction)); two-stroke oil: oil equivalent to the mass of the reference oil (the source text source-text extraction is "equivalent to reference. dagger oil mass oil one", requires confirmation against the source standard (source-text extraction)); time 2h (break-in at each load); load 0W, 200W, 400W, 600W, 800W (the source text source-text extraction is ".、2 0 0 ,。、，、8 0 0 one", requires confirmation against the source standard (source-text extraction)).
• 7.1.2 Adjustment of engine speed: Move the frequency control lever position and adjust the engine speed adjustment bolt to satisfy the following speeds at the two loads:
  • At 50Hz, 670W: 3000r/min±50r/min
  • At 60Hz, 750W: 3600r/min±50r/min
• 7.1.3 Determination of fuel flow: After break-in is completed or after a one-week interval between tests, reconfirm the fuel flow and adjust it to the following ranges:
  • 50Hz No load: 350mL/h±20mL/h
  • 50Hz, 670W: 630mL/h~670mL/h
• 7.1.4 Adjustment of fuel flow under no load: When the fuel flow under no load does not meet the requirement of 7.1.3, adjust according to the following method: if the fuel flow is low, turn the fuel adjustment screw counterclockwise; if the requirement still cannot be met, replace with a nozzle one size larger. If the nozzle currently in use is No. 32.5, replace it with No. 35. Figure 15 indicates the positions of the fuel adjustment screw and nozzle.
• 7.1.5 Determination of engine condition: The exhaust smoke of the calibration oil should be within the range shown in Table 2. If it is not within this range, the fuel flow must be adjusted according to the method in 7.1.4.
  • Table 2 Exhaust smoke of calibration oil: JATRE-1: 20±3%; JATRE-3: 40±30% (reference value) (the source text source-text extraction is "40330 reference value", requires confirmation against the source standard (source-text extraction)).
• 7.1.6 Parts replacement: The parts to be replaced and the replacement intervals are shown in Table 3.
  • Table 3 Parts replacement table (part name | part number | replacement interval):
    • Piston | 12110-87601 | Every time the cylinder head is installed
    • Piston ring | 12140-87600 | Every time the cylinder is installed
    • Cylinder | 11211-87600 | When necessary
    • Cylinder head gasket | 11141-91A00 | When necessary
    • Cylinder gasket | 11241-87600 | When necessary
    • Small end ball bearing | 09263-10010 | When necessary
    • Piston pin | 12151-87600 | When necessary
    • Piston pin retaining ring | 09381-10006 | When necessary
    • Exhaust pipe gasket | 14140-87600 | When exhaust leaks occur
    • Spark plug | 09482-10103 (original source-text extraction is "09482[unreadable separator and character]10316", requires confirmation against the source standard (source-text extraction)) | At the start of each day's test
  • Note: The components in the table shall be replaced when necessary according to the maintenance manual prepared by the engine manufacturer.
• 7.1.7 Removal of carbon deposits from the combustion chamber and exhaust port: After every 75 smoke measurements, remove the cylinder head and remove carbon deposits from the piston top, cylinder head, and exhaust valve.
• 7.1.8 Removal of carbon deposits from the muffler: Periodically (every 50h of engine operation), remove carbon deposits from the muffler. The following two removal methods are recommended:
  • Method one: Clean with the carbon deposit cleaning agent of the formulation in Appendix D.
  • Method two: Use a high-temperature furnace (such as an electric resistance furnace) to burn the entire muffler until red hot, remove the carbon deposits in the muffler, and then wash with water.
  • When the above methods cannot restore the engine to its original output power, the muffler should be replaced. If the power still cannot be restored after using a new muffler, the engine should be overhauled or replaced with a new engine.
• 7.4 Preparation of the smoke meter: Before measuring smoke, the smoke meter shall be powered on for 1h to prevent zero drift. After adjusting the zero point of the smoke meter, calibrate the smoke meter with a standard mirror, and at the same time adjust the zero point and scale of the recorder.

7. Sampling and specimen preparation

• 7.2 Preparation of mixed fuel: According to the volume ratio of fuel to two-stroke oil 10:1, separately blend the mixed fuel of reference oil and test oil, each in an amount of about 1L. If separation occurs between the two-stroke oil and the fuel, the test shall not be conducted, and this shall be stated in the test report in Appendix E.
• 7.3 Cleaning of the mixed fuel system: Each time the mixed fuel is changed, clean the fuel tank thoroughly with the test fuel, and drain the residual oil in the fuel pipe, fuel pressure regulator, and carburetor. After filling the fuel tank with new mixed fuel, drain about 100mL of mixed fuel from the carburetor drain port (original source-text extraction is "about 1[unreadable character]nJ'", requires confirmation against the source standard (source-text extraction)).

8. Analytical procedure

• 8.1 Test procedure:
  • 8.1.1 To remove residual oil from the muffler, wrap the muffler with insulation. Move the frequency control lever on the generator to 60Hz (original source-text extraction is "[garbled frequency value/unit]", requires confirmation against the source standard (source-text extraction)). Start the engine and run it under 750W load. When the exhaust temperature reaches 320℃ and the exhaust smoke is less than 0.5%, stop the engine. If the exhaust smoke does not become less than 0.5%, continue running the engine for 15min and then stop (original source-text extraction is "[unreadable value/unit]n", requires confirmation against the source standard (source-text extraction)).
  • 8.1.2 Remove the insulation and blow air to cool the engine. Cool the engine to a spark plug gasket temperature of 40℃±5℃ (original source-text extraction is "[unreadable value]℃[unreadable sign]5℃", requires confirmation against the source standard (source-text extraction)); at this time the exhaust temperature is usually below 50℃. During the cooling process, the zero points of the smoke meter and recorder must be adjusted, and the smoke meter must be calibrated with a standard mirror.
  • 8.1.3 Push the frequency control lever back to 50Hz, start the engine, and run it under no load for 20min (original source-text extraction is "2 0[unreadable unit character]n", requires confirmation against the source standard (source-text extraction)). Record the exhaust smoke during this process as a reference value.
  • 8.1.4 Switch the load to 670W±10W, read the maximum exhaust smoke value, and use it as the data for calculating the smoke index. Continue running the engine until the exhaust smoke decreases, then stop.
• 8.2 Within the same day, test in the order of reference oil JATRE-1— test oil—reference oil JATRE-1 (original source-text extraction is "」ATRE[unreadable separator]1–one or two test oils–reference oil 」ATR[garbled characters]1", requires confirmation against the source standard (source-text extraction)). Repeat the test procedure 3 times for each oil 8.1, and obtain three maximum exhaust smoke values for each.
• 8.3 Determination of the maximum smoke value: Exhaust smoke is affected by many factors, so the smoke meter must be placed strictly according to 5.9. In 8.1.4, the maximum value displayed by the smoke meter indicator is called the maximum smoke. An example of maximum exhaust smoke is shown in Figure 16, in which A is the maximum smoke value.
• 8.4 Measurement records: Table 4 lists the measurement items. Record the measured data in Appendix E.
  • Table 4 Items requiring measurement (measurement conditions | measurement items):
    • At 60Hz, 750W | Engine speed, r/min
    • At 50Hz, 670W | Generated current, A
    • At 50Hz, 0W, before load change | Spark plug gasket temperature, ℃
    • At 50Hz, 0W, before load change | Exhaust temperature, ℃
    • At 50Hz, 670W, at maximum smoke | Exhaust temperature, ℃
    • At 50Hz, 0W, before load change (reference value) | Exhaust smoke, %
    • At 50Hz, 670W, at maximum smoke | Exhaust smoke, %
    • Before and after test | Humidity, %
    • Before and after test | Atmospheric pressure, kPa

9. Qualitative and quantitative determination and calculation formulas

• 9.1 Conditions for valid test results: If the deviation Y(%) of the smoke of two tests of the reference oil is within the range of ±15%, the test results are valid; otherwise they are invalid. Calculation method:
  • Y(%) = [(B-A)/A] × 100 ……………………………………(1)
  • Where: A— average of the three maximum smoke values of the first test of the reference oil; B— average of the three maximum smoke values of the second test of the reference oil.
• 9.2 Calculation of the smoke index:
  • Test oil smoke index = (SR/St) × 100 ……………………………………(2)
  • Where: SR— average of the six maximum smoke values of two tests of the reference oil; St— average of the three maximum smoke values of the test oil.
  • The smoke value shall be taken to one decimal place, and the smoke index shall be taken as an integer.
• 9.3 Report: Report the test results according to Appendix E.

10. Precision

No independent precision section is provided in the available source. Only the condition for valid test results is seen in 9.1: if the deviation Y(%) of the smoke of two tests of the reference oil is within the range of ±15%, the test results are valid; otherwise they are invalid.

11. Report

Report the test results according to Appendix E. Appendix E is the "Exhaust Smoke Test Report for Air-Cooled Two-Stroke Gasoline Engine Oils" (an appendix of the standard). Table E1 contains the following contents:

• Test method, submitting unit, test date, test number, oil sample name
• Oil sample: JATRE-1, JATRE-1 (original source-text extraction is "JATBE[unreadable separator]1", requires confirmation against the source standard (source-text extraction))
• Test number: 1, 2, 3 (for each oil sample)
• Exhaust smoke %: 50Hz/0W, 50Hz/670W
• Gasket temperature ℃: 50Hz/0W, 50Hz/670W
• Exhaust temperature ℃: 50Hz/0W, 50Hz/670W
• Engine speed r/min: 50Hz/670W, 60Hz/750W (original source-text extraction is "[unreadable value]Hz,50W", requires confirmation against the source standard (source-text extraction))
• Room temperature, ℃; atmospheric pressure, kPa; humidity, %
• Average smoke, %: A, C, D, B
• [(B-A)/A]×100%
• Determine whether it is within the range of ±15%
• Average smoke of A and B, %
• Smoke index
• Remarks
• Test personnel, report, review

12. Normative references

The provisions contained in the following standards constitute a part of this standard through reference. Unless otherwise clearly specified in this standard, the above referenced standards shall be the currently effective versions.

• GB/T 264 Determination of acid value of petroleum products
• GB/T 265 Determination of kinematic viscosity of petroleum products and calculation of dynamic viscosity
• GB/T 268 Determination of carbon residue of petroleum products (Conradson method)
• GB/T 380 Determination of sulfur content of petroleum products (lamp method)
• GB/T 2433 Determination of sulfate ash of additives and additive-containing lubricating oils
• GB/T 5487 Determination of gasoline octane number (research method)
• GB/T 6536 Determination of distillation of petroleum products
• GB/T 8017 Determination of vapor pressure of petroleum products (Reid method)
• GB/T 8019 Determination of actual gum in automotive gasoline and aviation fuels (jet evaporation method)
• GB/T 8020 Determination of lead content in gasoline (atomic absorption spectrometry)
• GB/T 11132 Determination of hydrocarbon types in liquid petroleum products (fluorescent indicator adsorption method)
• SH 0041 Unleaded automotive gasoline
• SH/T 0251 Determination of base number of petroleum products (perchloric acid potentiometric titration method)
• SH/T 0260 Evaluation method for high-temperature detergency of ordinary diesel engine oils (1105 single-cylinder evaluation method)

Editor's note: The standard numbers and standard names of the referenced standards in this standard have changed as follows:

• Original standard number SH 0041 → current standard number SH 0041-93, current standard name: Unleaded automotive gasoline

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

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