AS 4430.1:2003 Evaluation of devices, additives and processes which claim to improve vehicle performance
A4.3 Valve seat recession test
Engine settings shall not be adjusted during the valve seat recession test. The valve seat recession test shall be carried out as follows:
(a) Condition with test fuel A and device fitted, if specified by the product supplier or vendor.
(b) Operate test engine at 2000 r/min with 50 Nm dynamometer brake load to stabilize coolant temperature.
(c) Open the throttle to the wide open throttle (WOT) position and load the dynamometer
to obtain a speed within 300 r/min of the speed midway between the engine
manufacturer’s quoted peak torque speed and peak power speed.
(d) The test shall comprise the following schedule:
(i) WOT and loaded as described in Step (b) for 27 minutes.
(ii) Idle for 3 minutes with no load added.
(iii) Repeat Steps (i) and (ii) 100 cycles (i.e. 50 hours total test duration).
(e) After 5 minutes of operation and at one hourly intervals, measure and record the following:
(i) Volumetric fuel flow rate.
(ii) Engine speed, torque, coolant temperature, oil temperature and oil pressure.
(iii) Intake air temperature, barometric pressure and relative humidity.
(iv) Exhaust emissions of hydrocarbons (HC) and carbon monoxide (CO).
(f) Oil cooling shall not be used during the test unless engine oil temperature exceeds 130°C.
(g) Check the oil level every 8 hours, if necessary top up and record the amount of oil added.
(h) Measure and record cylinder compression pressure at 1 hour, 25 hours and at the end of the test, while the engine is hot. For the final compression check, remove fuel from the carburettor float bowl and disconnect the fuel line to avoid petrol staining the combustion chamber.
(i) Measure and record valve stem heights as shown in Figure A2, at 1 hour, 25 hours and at the end of the test, when the engine is at ambient temperature*. Valve stem heights shall be measured at the same engine temperature throughout the test sequence. For the purposes of this Standard ambient temperature means that the engine coolant temperature shall be within 3°C of the ambient air temperature and all such measurements shall be made at ambient temperatures not varying by more than 5°C.