By the time you read this, the weather will be turning cooler across our fair land, but as we write it, many parts of the world are experiencing an unusually hot summer. Lots of us drive performance vehicles that tend to generate more heat than the average commuter car, and when ambient temps go up, the weak links in our cooling systems are often revealed. Maintaining engine temperature has been a challenge since internal combustion was first invented, and even today we still battle with engine heat, particularly in modified vehicles. So even if you're starting to think about using the heater again, this is a good time to sort out those hot topics you may have had last summer.
Cooling systems seem simple, since they have relatively few components and use little or no electronics to function. In truth, even a basic cooling system on a vintage car is the result of many hours of engineering and testing, as numerous factors and variables must be taken into consideration to ensure that the little needle on the dash never swings past the acceptable level. Diagnosing problems with these systems later on can be difficult and frustrating, often resulting in a string of unnecessarily replaced parts and a persistent problem. We've compiled some information on cooling system basics to help you understand how they work, and how to keep your car in the black when the mercury climbs into the red.
Most of us know the basics of a typical cooling system. The engine water pump pressurizes the system and pushes coolant through the engine and then through the radiator where the heat absorbed by the coolant from the engine is transferred to the metal of the cooling tubes and fins in the radiator. The air that passes over these fins pulls the heat out of the radiator. The coolant, at a 30- to 40-degree lower temperature, is then pumped back into the engine to start the process over again. This sounds simple, but there are plenty of variables that affect the cooling system performance. Let's look at the cooling system one component at a time.