115
Run In
The run in of a rebuilt engine will often determine the oil
consumption, power output, and other variables during the
service life of the engine. It is important to run in a rebuilt
engine properly. How an engine will be run in is determined
by the type of equipment and the time that is available.
Thermo King recommends an engine be run in on a dyna-
mometer if possible.
Dynamometer Run In Procedure
1. Pressurize the lubrication system of the engine with an
oil pressure tank if the engine has been stored for any
length of time. This prevents a dry start.
2. Start the engine and run it at 1400 rpm with a load that
is 6 to 8% of the engine’s rated output for a short time.
3. Run the engine at 1400 rpm with a load that is 15% of
the engine’s rated output for 15 minutes.
4. Run the engine at 2400 rpm with a load that is 22 to
25% of the engine’s rated output for 30 minutes.
5. Run the engine at 1400 rpm with a load that is 15% of
the engine’s rated output for 30 minutes.
6. Run the engine at 2400 rpm with a load that is 30 to
35% of the engine’s rated output for 10 minutes.
7. If time permits, additional run in time is desirable. Vary
the speed and load in ranges between 1400 to 2400 rpm
and 10 to 25% of the engine’s rated output.
Run In Procedure Without Dynamometer
1. Run the engine on a test stand with no load for approxi-
mately 15 minutes in both low speed (1400 rpm) and
high speed (2400 rpm). Check the engine for abnormal
noises, coolant, fuel, or oil leaks.
CAUTION: DO NOT run a newly rebuilt engine with-
out a load for a long period of time. This can cause
the engine’s oil consumption to be higher than
normal.
2. Mount the engine in a unit and run the unit on high
speed heat for 2 hours. Occasionally place the unit in
low speed heat to vary the compression pressures and
engine temperatures.
3. Mount the unit on a truck and run the unit in high speed
heat with truck doors open for 2-10 hours.
Valve Clearance Adjustment
The valve clearance should be checked after the first 500
hours of engine operation and every 2000 hours after that. It
is very important to have the valves adjusted properly. If the
valve clearance is too small, that cylinder may lose com-
pression, misfire, and burn the valve and valve seat. If the
valve clearance is too large, the valve will be noisy and the
valve and rocker arm may wear abnormally. Adjust the
valves at room temperature with the valves closed.
Two Cylinder Procedure
1. Remove the valve cover.
2. Torque the cylinder head bolts to the proper torque.
NOTE: The cylinders on these engines are numbered
from the flywheel end to the water pump end. The
number 1 cylinder is next to the flywheel. The number
2 cylinder is next to the water pump. The timing
marks on the flywheel are also numbered this way.
The timing marks on the flywheel of the two cylinder
engines are stamped 180 degrees apart. The top dead
center marks have the cylinder number stamped next
to them. The injection timing marks have no identifi-
cation marks.
The index timing mark is stamped on the side of the
starter mounting plate that faces the flywheel. This
timing mark is on the intake side of the engine.
