Gerald Stringer, Aaron’ s sales director, explains the main differences between the two types of upgraded core.‘ Firstly, there’ s an X-type Packed Construction core that has more tubes and a higher fin pitch to increase the surface area that the cool air flows over. The X-type is the most efficient core available in copper and brass and is available in many different numbers of rows, thicknesses. There’ s also an upgraded Tube & Fin available which, though not quite as efficient as the X-type, is more durable and resistant to vibration.’
What are the advantages of either a copper core, or an aluminium one?’ Copper is much better at transferring heat than aluminium, but the copper and brass( C & B) core is lead / tin soldered together, and lead is a bad conductor of heat. Aluminium cores, on the other hand, are brazed together so they are 100 % aluminium alloy.
‘ In the end, though, cores of a similar thickness have about the same cooling efficiency due to the wider, more efficient tubes in the alloy core versus the narrower tubes in the C & B core.
‘ A C & B core is more easily repaired, while an alloy core is much lighter. 30 to 40 % lighter. In classic cars, C & B is usually original, so this is authentic, but alloy can be polished for a custom look or powdercoated for a more traditional appearance.
‘ We recondition all radiators in our London factory in either traditional copper and brass or aluminium from European-sourced materials. For a simple recore, C & B has always been much cheaper than aluminium, but with copper prices rocketing, the difference is becoming less. If a complete radiator needs to be built, it would probably be cheaper and more attractive in alloy.
In modern classics that use radiators with plastic tanks, Aaron remakes replacements in aluminium when the originals aren’ t available
It’ s not just radiators that Aaron repairs and remakes; the company reproduces fuel tanks, too
‘ If the car is all original and you just want the existing radiator recored, stick with an upgraded copper and brass radiator unless weight really is an issue. Doing so will ensure you keep your radiator as efficient as possible whilst maintaining your car’ s originality.
‘ If you are modifying a car, particularly upgrading the engine, and cooling requirements have greatly increased – or a much lighter unit is required – replace the radiator with a thicker alloy one. Especially for race applications.’
Summer 2026 The Engine Rebuilder 39