Volvo Penta KAMD300, Installation Manual, Page: 106 / 140

Engine room, ventilation and sound proofing
104
Engine power output and air temperature
The engine’s stated power output applies at an air
temperature of +25°C (77°F), air pressure of 100 mbar
(750 mm Hg), relative humidity 30%, fuel temperature
+40°C (104°F) and seawater temperature of +32°C
(90°F). (According to International test standards).
Adequate air supply and ventilation makes it possible
to obtain as high a power output as possible together
with a long engine life.
If the inlet air for the engine cannot be kept below
+25°C (77°F), the power output drops by up to 1.5%
for turbocharged engines and 1.0% for turbocharged
engines with aftercooler for every 10°C (18°F)
increase in air temperature. For normally aspirated
engines, this figure can be up to 2%. In those places
in the world where the air temperature is constantly at
or above 45°C (113°F), diesel engines must be de-
rated, i.e. the injection pump adjusted to a lower
injection quantity.
IMPORTANT! In those cases where operation is
at full throttle and the injection pump is not ad-
justed (de-rated) despite high air temperature, the
result will be very smoky exhaust, increased
thermal load and greatly increased engine wear
and consequently greatly increased operating
costs.
However, the driver can reduce the throttle when op-
erating temporarily in such hot areas and thus avoid
these types of unfavourable operating conditions.
Engine power output at high altitudes
above sea level
In most cases, marine engines are run at or near sea
level. There are, however, some lakes that are situat-
ed at high altitudes above sea level.
There is loss of power when operating at high altitudes
due to the fact that the air density (and therefore
oxygen content) decreases as altitude increases. This
results in smoky exhaust and the turbocharger
operating at abnormally high speeds with increased
wear.
The loss of power is, however, not important until
approx 500 m (1640 ft) above sea level.
At altitudes of more than 500 m (1640 ft) above sea
level, there is a loss of power of approx 0.1% per 100
m (328 ft).
De-rating should be done for high altitudes (reduced
fuel quantity) according to the following:
Altitude above sea Reduced fuel
level, metres (feet) quantity%
1000 (3280) 4
1500 (4920) 8
2000 (6560) 12
2500 (8200) 17