13.2.1 Run-In Instructions
g. Adaptor for connecting a vacuum gage or water
power absorbed in a water brake type dynamometer, as
manometer to the blower inlet.
an example, is governed by the volume of fluid within
the working system. The fluid offers resistance to a
h. Adaptor for connecting a fuel pressure gage to
rotating motion. By controlling the volume of water in
the fuel manifold inlet passage.
the absorption unit, the load may be increased or
decreased as required.
The power absorbed is generally measured in torque
(Ib-ft, on a suitable scale. This value for a given engine
speed will show the brake horsepower developed in the
engine by the following formula:
In some cases, gages reading in pounds per square inch
are used for determining pressures while standard
BHP - (T x RPM)/5250
characteristics are given in inches of mercury or inches
of water. It is extremely important that the scale of such
a gage be of low range and finely divided if accuracy is
desired. This is especially true of a gage reading in psi,
RPM - revolutions per minute
the reading of which is to be converted to inches of
water. The following conversion factors may be helpful.
Some dynamometers indicate direct brake horsepower
readings. Therefore, the use of the formula is not
Inches of water - psi x 27.7"
required when using these units.
Inches of mercury - psi x 2.04"
During the actual operation, all data taken should be
NOTE: Before starting the Run-In or starting the
recorded immediately on an Engine Test Report (see
engine for any reason following an overhaul, it is of
sample on page 4).
extreme importance to observe the instructions on
Preparation for Starting Engine First Time in Section
required to complete the Engine Test Report may be
obtained. The following list contains both the minimum
The procedure outlined below will follow the order of the
amount of instructions and the proper location of the
sample Engine Test Report.
fittings on the engine so that the readings represent a
true evaluation of engine conditions.
a. Oil pressure gage installed in one of the engine
Fill the lubrication system as outlined under
main oil galleries.
Lubricating System -- Preparation for Starting Engine
First Time in Section 13.1.
b. Oil temperature gage installed in the oil pan, or
Prime the fuel system as outlined under Fuel
thermometer installed in the dipstick hole in the
System -- Preparation for Starting Engine First Time in
A preliminary valve clearance adjustment must
c. Adaptor for connecting a pressure gage or
be made before the engine is started. See Valve
mercury manometer to the engine air box.
Clearance Adjustment in Section 14.1.
A preliminary injector timing check must be
d. Water temperature
made before starting the engine. See Timing Injector in
Preliminary governor adjustments must be
e. Adaptor for connecting a pressure gage or water
made as outlined in Section 14.
Preliminary injector rack adjustment must be
made - see Section 14.
f. Adaptor for connecting a pressure gage or
mercury manometer to the exhaust manifold at
1970 General Motors Corp.