SAE J1228:2002 pdf download

SAE J1228:2002 pdf download Small Craft—Marine Propulsion Engine and Systems—Power Measurements and Declarations
3. Definitions and Declarations
3.1 Declared Engine Speed (Crankshaft Speed)
3.1 .1 In the case of spark-ignition engines without speed governor, the declared engine speed shall be the midpoint of the full throttle speed range recommended by the manufacturer for propeller selection.
3.1 .2 In the case of engines with speed governors, the declared engine speed shall be the governed speed chosen by the manufacturer.
3.2 Declared Power—The corrected net brake power declared for a given engine or propulsion system at its final output shaft when all the auxiliaries which affect the power output are fitted. The declared power shall be determined and corrected according to ISO 3046-1 .
3.2.1 The declared power shall be “propeller shaft power” and so named at the propeller shaft of engines sold with complete propulsion units, and at the coupling to the propeller shaft of engines sold with reduction or reversing gears.
3.2.2 The declared power shall be “crankshaft power” and so named at the engine output shaft of engines sold without reduction or reversing gears or stem drives or sail drive units. In such cases, the power declaration shall be accompanied by a statement that usable power will be reduced by gear losses.
4. Test Equipment
4.1 Engine or Propulsion System
4.1 .1 The test engine or propulsion system shall be representative of the manufacturer’s production units. It shall be run-in according to the manufacturer’s recommendations and shall be fitted with an exhaust system. All auxiliaries fitted shall be listed and described.
4.1 .2 Carburetor wedges may be removed or added to maintain the carburetors at a normal running angle if the engine is tested in a horizontal position.
4.1 .3 If the exhaust system as delivered is not complete, the back-pressure at the declared engine speed shall be within ±0.75 kPa of the maximum back-pressure specified by the manufacturer at which the declared power can be achieved. If the exhaust system as delivered is complete, the laboratory exhaust system shall maintain the exhaust pressure at the unit outlet within ±0.75 kPa of the barometric pressure at the test bed. NOTE—The maximum permissible back-pressure declaration is required by ISO 3046-1 .
4.1 .4 If the engine air inlet is connected to a laboratory air system, the system shall supply air to the engine within ±0.75 kPa of the barometric pressure at the test bed.
4.1 .5 For liquid-cooled engines, the temperature of the coolant at the raw-water inlet shall be maintained at 298 K ± 1 5 K (25 °C ± 1 5 °C) except that for engines with charge air cooler the temperature shall be maintained at 298 K ± 5 K (25 °C ± 5 °C).