COOLING SYSTEM
7.7.9
MINIMUM COOLANT TEMPERATURE
The overall design should ensure minimum coolant temperature 71°C (160°F) be maintained
under all ambient operating conditions; operating conditions are listed in the “Technical Data”
section of this manual (refer to section 14). A cold running engine can result in poor engine
performance, excessive white smoke, and reduced engine life.
7.7.10
SYSTEM PRESSURIZATION
MBE4000 engines require a minimum 15 psi pressure cap. The speci
fi
c requirements are listed
in the “Technical Data” section of this manual (refer to section 14). The pressure caps raise the
boiling point of the coolant which minimizes coolant or
fl
ow rate loss due to localized boiling and
water pump cavitation. Higher rated pressure caps may be required for high altitude and severe
ambient operation. Cooling system components
must
be able to withstand increased pressure.
7.7.11
COOLANTS
A proper glycol (ethylene, propylene) or extended life organic acid, water, Supplemental Coolant
Additive (SCA) mixture meeting DDC requirements is required for year-round usage.
The coolant provides freeze and boil protection and reduces corrosion, sludge formation, and
cavitation erosion. Antifreeze concentration should not exceed 67% for ethylene glycol (50% for
propylene glycol). Detroit Diesel requires SCAs be added to all cooling systems at initial
fi
ll and
be maintained at the proper concentration. Follow SCA manufacturers' recommendations. Refer
to
Coolant Selections for Engine Cooling Systems
(7SE0298), available on the DDC extranet.
7.8
CHARGE AIR COOLING REQUIREMENTS
Suf
fi
cient cooling capability is required for optimum engine performance. Exceeding the system
temperature and pressure design limits de
fi
ned in this chapter can adversely affect fuel economy,
power, emissions and durability.
7.8.1
COOLING CAPABILITY
The cooling capability of the air-to-air system must be suf
fi
cient to reduce the turbocharger
compressor out air temperature to within 21°C (38°F) of ambient temperature on all MBE
on-highway engines. Air inlet manifold temperature requirements are listed in the “Technical
Data” section of this manual (refer to section 14).
7.8.2
MAXIMUM PRESSURE LOSS
The maximum allowable total static pressure drop across the MBE4000 charge air system is 10.0
kPa (3 in. Hg). This includes the restriction of the charge air cooler and all the plumbing and
accessories from the turbocharger compressor to the engine air inlet manifold.
7-16
All information subject to change without notice.
(Rev. 03/06)
7SA250 0603
Copyright © 2006 DETROIT DIESEL CORPORATION
