
Charge Air Cooler Restriction
Measure the intake pressure drop across the charge air
cooler.
This test can be done with a mercury manometer or two
separate gauges, Part No. ST-1273. If two gauges are
being used, calibrate both gauges on a common pressure
source at 206 kPa [30 PSI] to ensure consistency.
Install one pressure gauge, Part No. ST-1273, in the
fitting in the turbocharger compressor outlet elbow. In-
stall the other pressure gauge in the fitting in the intake
manifold.
Observe the reading on the gauges. Pressure drop must
not be greater than:
102 mm Hg [4.0 in. Hg]
14 kPa [2.0 psi]
NOTE: When measuring the pressure drop, operate a dy-
namometer at the rpm that delivers the maximum horse-
power of engine tested. Engine speed will be 1600-1700 rpm
on most engines.
Intake Air Restriction
Measure the inlet air restriction. Install the vacuum gauge,
Part No. ST-434, or a manometer in the intake air piping.
NOTE: The gauge adapter must be installed at a 90 degree
angle to the air flow in a straight section of pipe at a minimum
of one pipe diameter before the turbocharger.
Engine Testing General Test Procedure - Chassis Dynamometer (14-05)
N14 Page 14-35
Perfect..