Cooling System: Description and Operation

Cooling







Since the 911 Carrera (997) is available in two engine types and the 3.8 liter engine has a higher cooling requirement than the 3.6 liter engine, the entire cooling system has had to be revised. A coolant pump with an approx. 13% increase in capacity is employed to this end. This increase in capacity results from an approx. 3 mm larger impeller and an enlarged coolant inlet on the crankcase. This necessitated corresponding modifications of the seals. The oil-water heat exchanger has been enlarged to incorporate two additional cooling fins. The efficiency of the front radiators also had to be improved.

Enlarging the radiators was not an option due to lack of space. A third radiator for cars with manual transmissions also was deemed unviable due to weight concerns. Taking these concerns into consideration, optimizing the existing cooling concept was the best option available.

Fine-tuning has improved the radiator core and increased the efficiency of the supply and exhaust channels in the body. In addition, variable speed control for the radiator fans has been introduced for the 911 Carrera (997) models.

The total of all the implemented measures resulted in a substantial improvement in cooling capacity. In order to reduce the extent of diversification, these modifications have been incorporated into both engine types.