Want to make your classic run happier when the weather gets hot? A more modern radiator could be the answer
Today’s road conditions place an awful lot of demands on older cars. So your engine runs hot, oil pressure drops, life gets stressful. Just making sure all the standard components are in tip-top shape doesn’t seem to be enough, so you try an electric fan and discover your dynamo can’t keep up with the electrical demand. So you fit an alternator, and on it goes…
Rather than trying to make the existing cooling system work harder, cooling nirvana can be achieved by fitting a better radiator. Modern radiator core technology is far more efficient than old designs, allowing much better heat transfer per square inch of radiator area. Yes, the fins look different, but it’s a small price to pay.
Early automotive radiators were either made of thick tubes covered with radial spines, or had upper and lower tanks with a honeycomb-pattern core in-between. These gave way to designs in which many narrow, flattened tubes between the tanks passed through thin, horizontal copper sheets, which acted as fins. The more fins and the more rows of tubes, the more efficient the radiator – up to the point at which the increased area of metal impedes the airflow too much, or the air reaches the coolant’s temperature before it has finished its journey through the radiator.
More recent cars use a different system, known as ‘packed construction’. Here, in the smaller spaces between a greater number of flattened tubes, the copper sheet is folded into fins in a zig-zag pattern. More tubes and a greater surface area of fins means more heat transfer. And instead of maybe four rows of tubes from the front of the radiator to the back, the system can use two rows of deeper tubes and increase the contact area between fins and tubes.
Even better, your new radiator (made by any good radiator specialist using your existing brass header and bottom tanks) can incorporate the latest in fin technology. It will now be as efficient as a copper-cored radiator can be.
Which leads to the idea of an aluminium radiator, either custom-built or, for some classics, available off the shelf. Aluminium isn’t as good a heat conductor as copper, but the zig-zag fins are welded to the tubes instead of soldered so overall heat transfer is better. Aluminium is lighter, too. Either way, you’ll no longer be blowing your cool.