Section 14 - Engine Testing - Group 14 Chassis Dynamometer (14-03) M11 Page 14-43 Intake Manifold Pressure Measure the intake manifold pressure (turbocharger boost). Install pressure gauge, Part No. ST-1273, in the intake manifold as shown. Observe the reading on the pressure gauge. NOTE: Intake manifold pressure (turbocharger boost) must be corrected for variances due to intake air temperature. Use the ‘Boost Pressure Correction Factor’s explained in gine Testing - General Information’’. Intake Air Temperature Control - Chassis Dyna- mometer Test When operating an engine on a chassis dynamometer, follow these steps for best results and safe operation.
Lock the cooling fan in the ‘‘ON’’ mode. This can be done by installing a jumper across the temperature switch, or by supplying shop air to the control valve. Refer to the fan drive manufacturer for the recommended procedure. Monitor the intake manifold air temperature using Compulink™in the monitor mode, or install Fluke digital thermometer, Part No. 3822666, and thermocouple wire kit, Part No. 3822988, into the intake manifold. The intake manifold air temperature must not exceed 77°C [170°F]. The engine protection system will disrupt performance if the temperatures exceed this level. Maintain intake manifold air temperature to 66°C [150°F] or below during chassis dynamometer operation.
If the intake manifold temperature exceeds 77°C [170°F], shut off the engine. Allow the engine to cool. Inspect the CAC fins for obstructions to the air flow. Check the fan drive. Make sure the fan is locked in the mode. Remove any obstructions such as a winterfront or debris. Manually lock the shutters in the position if equipped. Inspect the dynamometer room for adequate supply of suitably cool or outside air. Make sure that dynamometer room recirculation is not an issue. Resume the test.