1 Subject content and scope of application This standard specifies the basic method for intensive testing of motorcycle and moped gasoline engines on the bench. This standard applies to reciprocating piston gasoline engines (hereinafter referred to as engines) for motorcycles and mopeds (except racing cars). 2 Reference standard GB 5363 Motorcycle and moped engine bench test methods. 3 Test conditions 3.1 Accessories 3.1.1 During the test, the engine must be equipped with all accessories for actual use. For example, if it is equipped with a charging and lighting generator or a charging lighting coil in the magneto, it can be placed in a no-load state. 3.1.2 Accessories brought during the test should be recorded in detail in the corresponding test record form and test report. 3.2 Power output During the test, the power is measured from the power output shaft (or equivalent part) of the engine (power is allowed to be measured after passing through the reduction gear, clutch and transmission high-speed gear). 3.3 Spark plugs When testing, the original spark plugs should be used as much as possible. If the original spark plug pad value is not suitable, a spark plug with a suitable calorific value can be used. 3.4 Measurement of main parts Before the test, the main parts (such as piston, piston ring, piston pin, cylinder block, connecting rod small end bushing, connecting rod, bearing bush, crank pin, main journal, main bearing bush, camshaft, valve, valve The main dimensions of pipes, etc.) are precisely measured. The non-detachable part of the crankshaft connecting rod assembly does not need to be measured. 3.5 Running-in Before the test, the engine should be run-in according to the running-in specifications recommended by the manufacturer. 3.6 Performance test Speed ??characteristic test should be carried out before intensive test. The speed characteristic test includes the speed characteristic test under full load and partial load. The specific items are: a) full load speed characteristic (external characteristic) test; b) 75% calibration power throttle opening speed characteristic test; c) 50% calibration Power throttle opening and speed characteristic test; d) 25% calibrated power throttle opening and speed characteristic test (engines with calibrated power below 1/84kW are not allowed to do this). 3.7 Engine cooling 3.7.1 When testing an air-cooled engine, the direction of the cooling air should be consistent with the wind direction that the engine experiences when the vehicle is running. Forced air-cooled engines must use their own cooling system, and external cooling air can also be appropriately added. 3.7.2 When testing a water-cooled engine, its own cooling system should be used for cooling, and external air source cooling is allowed. 3.8 Engine installation and exhaust back pressure The engine should be installed on the test bench according to the installation angle used. The exhaust should be discharged into the atmosphere, and the pressure difference between the exhaust tail pipe and the atmosphere should not be greater than ±740kPa. 3.9 Temperature control 3.9.1 Spark plug gasket temperature The spark plug gasket temperature of air-cooled engines should not be lower than 443K for two-stroke engines and 453K for four-stroke engines. The upper limit should comply with the manufacturer's regulations. 3.9.2 Lubricating oil temperature The lubricating oil temperature of the four-stroke engine should be controlled within the range specified by the manufacturer (or shall not exceed 373K). 3.9.3 Cooling water temperature The cooling water outlet temperature of water-cooled engines shall be within the range specified by the manufacturer (or shall not exceed 368K). 3.10 Fuel and lubricating oil The fuel and lubricating oil used for testing should comply with the brands specified by the manufacturer. 3.11 Test equipment and instruments Test equipment and instruments should comply with the regulations of GB 5363. 4 Enhanced test method 4.1 Test procedure: running-in→machine disassembly and cleaning→precision measurement of main parts→installation adjustment (including replacement of lubricating oil)→performance test→intensified test (according to Tables 1 and 2)→maintenance adjustment→performance test→disassembly Machine cleaning → Precision measurement of main parts. 4.2 After 15 hours of continuous operation of the intensive test (excluding the running-in operation time and the performance test time before and after the intensive test), the engine can be maintained according to the items specified in the instruction manual. 4.3 The specifications for intensive testing of various types of engines are as specified in Table 1, and the duration is as specified in Table 2.
Table 1 Serial number Percentage of rotational speed at maximum power Power per liter of maximum power kW/L Percentage of maximum power Running time h Remarks 1 100 ≤44 86 3 ＞44～59 84 ＞59～70 82 ＞70 80 2 Maximum torque speed % of maximum torque 2 100 ≤44 90 ＞44～59 89 ＞59～70 87 ＞70 85 Table 2 Displacement ml ≤50 ＞50～125 ＞125～250 ＞250 Running time h 30 35 40 45 4.4 During the test, pay close attention to the engine operation and record in detail all situations that occur during the entire test. For example: shutdown failure, replacement of the name and quantity of non-main parts, damage to main parts, etc. 4.5 During the test, measure the speed, torque, power, fuel consumption rate, spark plug gasket temperature, cooling water outlet temperature and record the atmospheric temperature, atmospheric pressure, relative humidity, etc. every hour.