MAK M20, Operating Instructions Manual

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Operational supervision
Exhaust system/supercharging
A3.06.06.02
M20/M25/M32/M43/M552C/M601C
en / 11.05.2000 BA000658 1/4
Ĺ
Exhaust temperatures
A comparison of the exhaust temperatures with the values in the acceptance test certificate or the
records during testing/sea trials is best suited to assess the thermodynamic performance of the
engine and to analyse any deviations from the new condition of the engine (supercharging,
injection, combustion). Injection pump or nozzle wear, for instance, will have a direct effect on the
thermal engine performance. The influence of the prevailing air intake conditions on the engine data
must be seen and taken into account.
The exhaust temperatures after the cylinders cannot be used for an exact performance assessment
of the individual cylinders as the exhaust temperatures measured in the cylinders are influenced to
a varying degree by turbulence influences in the exhaust manifold. Any deviations among the
cylinders within the scope of the values given in the acceptance test certificate are perfectly normal
despite balanced individual cylinder power. Such as measurement therefore only has a limited
informative value which could be misleading.
Attention:
It is not permissible under any circumstances to alter the fuel injection or feed data on the
injection pumps to obtain identical temperature readings! This would unbalance the
power of the cylinders!
Provided the fuel cam setting is correct, the fuel injection of the injection pumps alone is decisive for
balancing the cylinder power values.
The temperatures after the cylinder, however, should not deviate more then
± 30 K
from the
respective cylinder value given in the acceptance test certificate
A1.10
.
Check the temperature after the cylinders regularly
.
The cause must be determined if there are any deviations (e.g. nozzle, injection pump, exhaust
valve), refer to A3.11.18.nn .