TM 5-3810-300-24&P-3
1 3.2.1 Run-In Instructions
3. A preliminary valve clearance adjustment must be
Any four or six cylinder Series 71 engine to be run at
made before the engine is started. See Valve Clearance
speeds in excess of 1800 rpm must be equipped with a
Adjustment in Section 14.1.
vibration damper.
4. A preliminary injector timing check must be made
Engine governors in most cases must be reset at the
before starting the engine. See Fuel Injector Timing in
maximum full-load speed designated for the Run-in. If a
Section 14.2.
governor is encountered which cannot be adjusted to this
speed, a stock governor should be installed for the Run-
5. Preliminary governor adjustments must be made as
in.
outlined in Section 14.
After checking the engine performance at idle speed and
6. Preliminary injector rack adjustment must be made
being certain the engine and dynamometer are operating
(Section 14).
properly, increase the engine speed to half speed and
apply the load indicated on the Basic Engine Run-In
Schedule.
B. BASIC ENGINE RUN-IN
The engine should be run at this speed and load for 10
minutes to allow sufficient time for the coolant
The operator should be observant at all times, so that
temperature to reach the normal operating range.
any malfunction which may develop will be detected.
Record length of time, speed, brake horsepower, coolant
Since the engine has just been reconditioned, this Run-in
temperature and lubricating oil pressure on the Engine
will be a test of the workmanship of the serviceman who
Test Report.
performed the overhaul. Minor difficulties should be
detected and corrected so that a major problem will not
Run the engine at each speed and rating for the length of
develop.
time indicated in the Basic Engine Run-In Schedule.
This is the Basic Run-In. During this time, engine
After performing the preliminary steps, be sure all
performance will improve as new parts begin to "seat in".
water valves, fuel valves, etc. are open. Also inspect
Record all of the required data.
the exhaust system, being sure that it is properly
connected to the engine. Always start the engine with
C. BASIC RUN-IN INSPECTION
minimum dynamometer resistance.
After the engine starts, if using a water brake type
While the engine is undergoing the Basic Run-In, check
dynamometer, allow sufficient water, by means of the
each item indicated in Section "C" of the Engine Test
control loading valves, into the dynamometer absorption
Report. Check for fuel oil or water leaks in the rocker
unit to show a reading of approximately 5 lb-ft on the
arm compartment.
torque gage (or 10-15 HP on a horsepower gage). This
is necessary, on some units, to lubricate the absorption
During the final portion of the Basic Run-In, the engine
unit seals and to protect them from damage.
should be inspected for fuel oil, lubricating oil and water
leaks.
Set the engine throttle at idle speed, check the
lubricating oil pressure and check all connections to be
Upon completion of the Basic Run-In and Inspection,
sure there are no leaks.
remove the load from the dynamometer and reduce the
engine speed gradually to idle and then stop the engine.
Refer to the Engine Test Report sample which
establishes the sequence of events for the test and run-
D. INSPECTION AFTER BASIC RUN-IN'
in, and to the Basic Engine Run-In Schedule which
indicates the speed (rpm), length of time and the brake
The primary purpose of this inspection is to provide a
horsepower required for each phase of the test. Also
fine engine tune-up. First, tighten the cylinder head and
refer to the Operating Conditions in Section 13.2 which
rocker arm shaft bolts to the proper torque. Next,
presents the engine operating characteristics.
complete the applicable tune-up procedure. Refer to
Section 14.
These characteristics will be a guide for tracing faulty
operation or lack of power.
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