CUMMINS N14 - INTAKE AIR RESTRICTION; EXHAUST AIR RESTRICTION

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.
Operate the engine at maximum horsepower RPM and
Advertised Horsepower.
Observe the reading on the gauge or manometer.
NOTE: Restriction must not exceed 635 mm H
2
0 [25 inches
H
2
0].
Exhaust Air Restriction
Measure the exhaust air restriction. Install the vacuum
gauge, Part No. ST-1273, or a manometer in the exhaust
air piping.
NOTE: The gauge adapter must be installed near the turbo-
charger in a straight section of pipe at the turbine outlet.
Engine Testing General Test Procedure - Chassis Dynamometer (8-06)
N14 Page 8-47