is delivered to the combustion chamber, a greater
amount of fuel is required to obtain the correct air-fuel
mixture. This increased consumption of fuel at the
correct air-fuel ratio results in increased power output.
Fig. 5. Air and Exhaust Flow In Turbocharged Engine
1. Air Intake
turbochargers are to be handled with extreme care. The
internal parts are manufactured to close tolerances and
are very sensitive to accumulations of dirt, nicks and
Care must be taken to prevent damage to the
components while they are on the workbench.
The turbine wheel, compressor impeller, shaft
and related parts form a balanced assembly which
rotates at very high speeds.
Bending of the turbine or compressor vanes or removal
of any vane material during servicing could cause a
serious out-of-balance condition which could quickly
destroy the turbocharger.
turbocharged engine makes it extremely important that
the air intake system be kept clean. The air cleaner
must be serviced at recommended intervals to avoid
power loss due to air cleaner restriction and to prevent
possible entry of dirt into the turbocharger and engine.
Turbocharging an engine is more than merely
bolting on the turbocharger and driving away. The
installation must be carefully engineered to provide the
best performance and avoid "overcharging" which could
be destructive. Also, the engine must be designed to
handle the greater air and fuel flow, higher pressures
and temperatures, and increased torque and power
After assembly, all openings in the turbocharger
should be capped or taped closed, or the entire
turbocharger should be encased in a clean polyethylene
bag to prevent entry of foreign material. Keep openings
covered until the unit is installed on the engine.
To prevent damage to the bearings, the
turbocharger must be prelubricated at installation or if the
engine has not been operated for a long period of time.
To prelubricate the bearings, place 4 to 5 ounces of
clean oil into the turbocharger oil inlet opening.
GENERAL MAINTENANCE AND CLEANING
Prevent the entrance of foreign material by
covering or plugging all openings into the
turbocharger when handling or assembling the
unit. Covers must remain in place until the
turbocharger is installed and all connections are
All connections to the turbocharger (manifolds
and piping) must be clean and free of foreign
connections must be airtight.
Exhaust stacks of extra long length and other
fixtures must not be rigidly attached to the
For initial running when installing a new or rebuilt
turbocharger or after the engine has been in
storage for 30 days or more or when engine oil
filters have been changed, it is recommended
that 4 to 5 ounces of oil (same type and grade as
used in the crankcase) be put into the oil inlet
opening in the turbocharger with a squirt can.
This will provide sufficient lubrication for the
turbocharger bearings until normal engine
Printed in United States of America