CYLINDER HEAD GP 7N8536 - Caterpillar

Basic troubleshooting procedures typically used to diagnose cooling system problems on generator set engines need to be expanded to include radiator sizing information. Before excessive diagnostic procedures are performed on generator set engines that utilize folded core radiators, cooling system requirements must be examined.
The ambient capability of a standard prime power generator set is 43.3°C (110°F) at 100% load factor. A standard standby generator set is 37.7°C (100°F) at 100% load factor. Consult the price list to verify the ambient capability of your specific package. These units are designed to operate up to the stated load factor (normally 100%) in ambient temperatures of 37.7°C (100°F) or 43.3°C (110°F) without overheating. Overheating is defined as top radiator tank temperature above 107.2°C (225°F). However, the radiator cooling systems are designed for a maximum normal operating water temperature of 98.9°C (210°F).
Various conditions and/or product configurations can decrease the ambient capability of a generator set. The actual ambient capability of the unit must be determined early in the diagnostic procedure.
The following items must be evaluated to determine their negative effect on the cooling capacity of the unit.
... Air-To-Core Rise - Air-To-Core Rise is defined as the difference between average radiator air inlet temperature and the actual ambient air temperature. This temperature rise takes into account any heat generating sources along the flow path of the cooling air.
Chart A lists estimated air-to-core rise from some typical installations.
... Antifreeze - Ethylene glycol provides freeze protection as well as increasing the boiling point of the coolant. Ethylene glycol also reduces the heat transfer capability of the coolant. The actual loss in ambient capability depends on many factors, however, the general rule is: The loss in ambient capability due to antifreeze is 1°C (1.8°F) for each 10 percent concentration up to 50 percent.
Concentrations above 50 percent cause even greater reductions in heat transfer loss.
... Altitude - All of Caterpillar's product performance curves, unless otherwise stated, are quoted at approximately 183 meters (600 feet) above sea level. Any change to this altitude must be taken into account.
The loss in ambient capability due to additional altitude above 183 meters (600 feet) is .3°C (.5°F) for each 61 meters (200 feet). Do not correct for altitude below 183 meters (600 feet).
Chart B shows the loss for various altitudes.
... Ten Percent Overload - If the unit is performing at 10 percent overload for emergency use, allow a 5.5°C (10°F) loss in ambient capability.
... Air Recirculation - Air recirculation can cause significant losses in ambient capability. Every effort should be made to minimize recirculation.
... Air Flow Restricting - Specific air flow restriction data can be obtained in the TIF microfiche. The maximum allowable restriction, measured in inches of water, will vary depending upon the specific fan and radiator configuration. This variable can have a substantial effect on system cooling capability and should be addressed as part of the sizing and/or troubleshooting procedures.
To determine actual ambient capability, subtract each value from the previous variables.
Part consist must be verified to determine correct