SH/T 0710-2001 Air-cooled two-stroke gasoline engine oil detergency evaluation method (EGD method)

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

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

• Standard number: SH/T 0710-2001
• Chinese name: Air-cooled two-stroke gasoline engine oil detergency evaluation method (EGD method)
• English name: Detergency test procedure for evaluating air-cooled two-stroke gasoline engine oil (EGD)
• Replacement relationship: not provided in the available source (the foreword only states equivalent adoption of CEC L-58-X-94, and does not mention replacement of an old standard)
• Adoption relationship: equivalent adoption of the EGD air-cooled two-stroke gasoline engine oil detergency test method of the European Coordination Committee (Coordinating European Council) CEC L-58-X-94
• Publication/implementation: published on 2001-11-23, implemented on 2002-01-01
• Issuing unit: State Economic and Trade Commission
• Proposing unit: China Petroleum & Chemical Corporation
• Technical committee unit: Sinopec Research Institute of Petroleum Processing
• Drafting unit: Research Institute of Maoming Branch, China Petroleum & Chemical Corporation
• Main drafters: Lin Yuesheng, Liang Qirui, Feng Xinping, Xu Shaojiong, Zhou Weizheng, Tang Tao
• Appendices: Appendix A, Appendix B, and Appendix C are all normative appendices

2. Scope of application and non-applicability

• Scope of application: This standard specifies the method for evaluating the detergency of EGD air-cooled two-stroke gasoline engine oils, namely the tendency of piston rings to stick at high temperature and the degree of cleanliness of engine pistons, cylinder heads, spark plugs, exhaust ports, etc. It is applicable to evaluating the detergency of EGD grade air-cooled two-stroke gasoline engine oils.
• Not applicable: not provided in the available source.

3. Method principle

This standard procedure uses a single-cylinder, air-cooled two-stroke engine with a displacement of 49 cm³ for the detergency test. After the engine has been run at 6000 r/min and low load for 10 min, it is run with the throttle fully open and then at full load [carbon monoxide concentration in the exhaust gas is 6.4%(V/V)±0.1%(V/V)] for 180 min. After the engine run is completed, the degree of piston ring sticking and formation of deposits on the piston and cylinder head caused by the lubricating oil is evaluated.

This standard uses JATRE-1 oil as the reference oil. The sample oil and the reference oil are tested in the specified order on the same day, and the fuel oil/lubricating oil volume mixing ratio is 50:1.

4. Reagents and materials (purity / preparation)

4.1 Test fuel

The test fuel is specially blended unleaded gasoline, and the quality indicators are shown in Table 2.

Table 2 Properties of fuel oil

Note: The specific values for the “not greater than” limits of actual gum and vapor pressure source-text extraction were not recognized and require confirmation against the source standard (source-text extraction).

4.2 Reference oil and calibration oil

• JATRE-1 oil is the reference oil for evaluating detergency.
• JATRE-1 oil and JATRE-3 oil are calibration oils.
• For performance, see Appendix A.

4.3 Mixed fuel

Before the test, the reference oil and the sample oil shall be mixed separately with the test fuel at a mixing ratio of 50:1, and the amount of mixed fuel used for each is about 4 L. If the mixed fuel shows phase separation, the test must be stopped and noted in the report.

5. Instruments and equipment

5.1 Test engine

The main technical specifications of the engine are shown in Table 1.

Table 1 Main technical specifications of the engine

5.2 Engine modification

• 5.2.1 Remove the transmission components from the engine crankshaft to the rear axle so that output power is taken directly from the crankshaft.
• 5.2.2 Modify the engine air guide shroud according to Figure 1 so that the airflow after cooling the cylinder does not blow toward the carburetor. Block the air outlet on the carburetor side and remove the guide plate facing the carburetor so that the cooling air flows smoothly toward the rear end.
• 5.2.3 Oil pump: use premixed fuel, do not use the oil pump, fill the oil pump inlet and outlet pipes with oil and short-circuit them to prevent the plunger from seizing, and block the carburetor oil inlet.
• 5.2.4 Do not use the fuel oil pump, and block the oil pump suction pipe installed on the crankcase.
• 5.2.5 Make a heat shield from materials such as aluminum, steel, or fiberglass-reinforced plastic and install it between the air filter and the muffler to minimize the influence of the exhaust pipe and cooling fan on the intake air temperature (see Figure 2).

5.3 Dynamometer

• 4000 At r/min, the absorbed power is 2.0 kW; at 6000 r/min, the absorbed power is 4.0 kW.
• The dynamometer must be directly connected to the engine crankshaft.

5.4 Cooling system

Remove the engine's own cooling fan and use an external air source to cool the engine. Between the engine and the blower, install a regulator to control the cooling air flow rate. The wind speed shall be adjusted so that during engine break-in the spark plug gasket thermocouple temperature is not higher than 180℃, and under rated conditions the temperature is not higher than 260℃.

5.5 Spark plug gasket

Install a thermocouple in the spark plug gasket (see Figure 3 and Figure 4). Control of the engine thermal load is achieved by controlling the gasket temperature.

5.6 Measurement of intake and exhaust temperatures and carbon monoxide concentration

During the test, in order to control the operating state of the engine, it is also necessary to measure the intake air temperature, exhaust temperature, and carbon monoxide concentration. The measurement locations are shown in Figure 5 and Figure 6.

5.7 Fuel supply system

The fuel tank is 0.5 m above the float chamber liquid level. Fuel is supplied by gravity pressure rather than by a fuel pump. The fuel line should reduce pressure loss, and its routing should avoid the occurrence of vapor lock in the pipe (see Figure 7 and Figure 8).

5.8 Test instruments and meters

• 5.8.1 The dynamometer's measurement range for engine output torque is 0~10 N·m, and the measurement accuracy is ±0.05 N·m.
• 5.8.2 The measurement accuracy of the tachometer is ±10 r/min (source-text extraction displays “±, Or/min”, requires confirmation against the source standard (source-text extraction)).
• 5.8.3 The accuracy of the thermometer (meter) is ±1℃.
• 5.8.4 Recorder: capable of continuously recording intake air, exhaust, and spark plug gasket temperatures, and capable of continuously recording engine output torque.
• 5.8.5 Fuel flow meter: measurement range is 0~3.0 L/h, measurement accuracy is ±1.0%; an electronic scale with an output signal may also be used.
• 5.8.6 Carbon monoxide concentration measuring instrument: range is 0~10%(V/V), measurement accuracy is ±0.1%(V/V).

6. Recommended operating conditions

6.1 Break-in operating conditions (Table 3)

During the stage II break-in, the throttle is fully open, the carbon monoxide concentration in the exhaust gas should be 6.4%(V/V)±0.1%(V/V), and the engine output torque should be at least 4.25 N·m. If it is not within this range, the carburetor main jet size and needle position should be adjusted. The recommended main jet model is 78A, and the needle clip is at the third notch from the top.

The mixed fuel used for break-in has a mixing ratio of 50:1(V/V). The lubricating oil is JATRE-1 reference oil.

6.2 Trial run conditions (Table 4)

6.3 Formal test conditions (Table 5)

Note: The data in parentheses are reference values and are not used as control values.

6.4 Measurement Record Items (Table 6)

7. Sampling and Test Sample Preparation

7.1 Engine Preparation

• 7.1.1 Break-in: For a new engine or an engine in which cylinder and crankshaft system components have been replaced, break-in shall be carried out according to the operating conditions in Table 3.
• 7.1.2 Engine assembly: For each cleanliness test with reference oil and test oil, new components shall be installed according to the requirements of Appendix B. Engine assembly shall be carried out according to the manufacturer's manufacturing and maintenance manual. During engine assembly, a thin layer of reference oil or test oil shall be applied to the surfaces of the components.
• 7.1.3 Engine adjustment and repair: When the engine speed is 6000 r/min and the decrease in full-load output power exceeds 10%, the engine shall be adjusted or repaired, and if necessary, a new engine shall be replaced, or component adjustment or replacement shall be carried out according to the manufacturer's maintenance manual.

7.2 Preparation of Mixed Fuel

Before the test, the reference oil and the test oil shall be mixed separately with the test fuel at a mixing ratio of 50:1, and the amount of mixed fuel for each shall be about 4 L. If stratification occurs in the mixed fuel, the test must be stopped and noted in the report.

7.3 Preparation of the Fuel Supply System

Before switching to the test oil test, the mixed fuel remaining in the fuel tank, fuel line, flow meter, and carburetor from the previous test shall be drained completely, and the fuel tank shall be rinsed with the test fuel. After filling with new mixed fuel, about 100 mL of the new mixed fuel shall be discharged from the carburetor drain.

7.4 Trial Run

Before the formal evaluation test, a trial run shall be carried out under the conditions in Table 4.

8. Analysis Procedure

After the trial run, without stopping the engine, open the throttle fully and immediately switch to the formal test under the conditions shown in Table 5, and measure and record the operating conditions according to Table 6. Since the test precision is mainly affected by the carbon monoxide concentration, when the carbon monoxide concentration is not within the specified range, the test shall be stopped and the engine readjusted. After the engine adjustment is completed, restart the test from the IIth stage of break-in.

9. Qualitative and Quantitative Evaluation and Calculation Formulas

9.1 End of Test

After shutdown, allow to cool naturally for 30 min before disassembling. Remove the piston from the engine, first evaluate the ring sticking condition, and then perform the cleanliness rating on the evaluated parts. Before the cleanliness rating, it is prohibited to clean the piston with solvent.

9.2 Evaluation

Perform the cleanliness rating of the parts according to the method specified in Appendix C.

9.2.1 Evaluated Parts

• A) Piston rings (sticking condition of the top ring and second ring);
• B) Piston ring lands (top ring land and second ring land);
• C) Piston ring grooves (top ring groove and second ring groove);
• D) Piston skirt;
• E) Piston inner crown;
• F) Piston outer crown;
• G) Cylinder head.

9.2.2 Weighted Scoring

The score of each part is multiplied by the weighting coefficient to obtain the weighted score.

Cleanliness index = [Σ weighted score of each part of the test oil / ΣJATRE-1 weighted score of each part of the reference oil] × 100

Piston skirt varnish index = [Σ score of each side of the piston skirt of the test oil / ΣJATRE-1 score of each side of the piston skirt of the reference oil] × 100

Note: The index is taken as an integer.

9.2.3 Commentary

• A) Spark plug damage condition;
• B) Exhaust port blockage condition;
• C) Damage condition of the piston pin and connecting rod small end bearing;
• D) Wear of the crankshaft main bearings and connecting rod big end bearings.

9.2.4 Recording and Photographing

Fill the evaluation results and test measurement parameters into Table 7 and Table 8, and photograph the evaluated parts. The locations are: cylinder head combustion chamber surface, piston outer crown, piston inner crown, exhaust side piston surface, intake side piston surface, right side piston surface in the piston pin hole direction, left side piston surface in the piston pin hole direction, spark plug electrodes and gap, a total of eight photographs, and indicate the test number, oil sample name, test date, and cleanliness index.

9.3 Appendix C Cleanliness Rating Method

C1 Piston Ring Sticking Rating (Table C1)

C2 Rating of Varnish and Deposits on Piston Ring Grooves, Ring Lands, Skirt, and Piston Inner Crown

Deposits with a thickness less than 0.1 mm are all rated as varnish. According to the SH/T 0510 color scale, determine the severity coefficient and area percentage of each part.

For the piston skirt, the evaluation area is limited to the contact surface, that is, the part in contact with the cylinder liner, excluding the area around the piston pin.

For the piston inner crown, the evaluation area shall be inside the piston and limited to the area from the piston top inner crown to the upper edge of the lowest piston ring groove. For irregular shapes, determine the evaluation area of each component separately. Use formula (C1) to calculate the total merit score.

For thick deposits (carbon deposits), use MR=0 as the severity coefficient and use formula (C1) to calculate the total merit score.

Total merit score = Σ( severity coefficient × area %) ………………(C1)

Example:

C3 Piston Top and Cylinder Head Deposits

Using the severity coefficients given in Table C2 and calculation formula (C2), calculate the total merit score of the deposits.

Total merit score = Σ( severity coefficient × area %) ………………(C2)

Table C2 Deposit Severity Coefficients and Calculation Formula

Example:

C4 Exhaust Port Blockage

Using the percentage of area blocked by deposits, use formula (C3) to calculate the total merit score.

Total merit score = 10 - (blocked area % × 100) ………………(C3)

C5 Spark Plug Condition

Describe the condition of the spark plug visually, using some of the expressions provided below:

• A) Normal deposits
• B) Center electrode bridging
• C) Gap bridging
• D) Other (describe the phenomenon observed)

C6 Test Report (Table C3)

EGD Air-cooled two-stroke gasoline engine oil detergency test result report, containing the following contents:

• Test date
• Scoring locations (weighting coefficients): piston ring land (2.3), second ring land (2.0), piston ring groove (1.0), second ring groove (0.6), piston skirt (1.3), piston inner crown (1.2), piston outer crown (0.5), piston outer crown (0.3), cylinder head (0.3)
• Total (maximum 100 points)
• Detergency index (JATRE-1=100)
• Skirt varnish index (JATRE-1=100)
• Measurement items (minimum value, maximum value, average value): fuel consumption, corrected torque, spark plug gasket temperature, exhaust temperature, intake air temperature, carbon monoxide concentration, engine speed, humidity, atmospheric pressure
• Check spark plug failure, check exhaust pipe blockage, check piston pin and bearing
• Remarks
• Test personnel, report, scoring

Note: In Table C3, the correspondence between weighting coefficients and scoring locations source-text extraction is misaligned, requires confirmation against the source standard (source-text extraction).

10. Precision

not provided in the available source.

11. Report

Fill in the EGD air-cooled two-stroke gasoline engine oil detergency test result report according to Appendix C Table C3, including: test date, scores and weighted scores for each scoring location, detergency index, skirt varnish index, minimum/maximum/average values for each measurement item, spark plug failure check, exhaust pipe blockage check, piston pin and bearing check, remarks, test personnel, reporter, scorer.

12. Normative References

• GB/T 265 Petroleum products — Determination of kinematic viscosity and calculation of dynamic viscosity
• GB/T 268 Petroleum products — Determination of carbon residue (Conradson method)
• GB/T 380 Petroleum products — Determination of sulfur content (Lamp method)
• GB/T 1884 Crude petroleum and liquid petroleum products — Laboratory determination of density (Hydrometer method)
• GB 1922 Solvent naphtha
• GB/T 1995 Petroleum products — Calculation of viscosity index
• GB/T 2433 Determination of sulfated ash from additives and additive-containing lubricating oils
• GB/T 5487 Gasoline — Determination of octane number (Research method)
• GB/T 6536 Petroleum products — Determination of distillation
• GB/T 7304 Petroleum products and lubricants — Determination of acid number (Potentiometric titration method)
• GB/T 8017 Petroleum products — Determination of vapor pressure (Reid method)
• GB/T 8019 Motor gasoline and aviation fuels — Determination of existent gum (Jet evaporation method)
• GB/T 8020 Gasoline — Determination of lead content (Atomic absorption spectrometry)
• GB/T 11132 Liquid petroleum products — Determination of hydrocarbon types (Fluorescent indicator adsorption method)
• GB 17930 Unleaded motor gasoline
• SH/T 0510 Engine test scoring method for gasoline engine oils
• SH/T 0667 Air-cooled two-stroke gasoline engine oil detergency evaluation method
• SH/T 0688 Petroleum products and lubricants — Determination of base number (Potentiometric titration method)

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.

14. Quick Reference Q&A