High-efficiency all-aluminium radiators are the modern performance upgrade for any classic MG running hot in modern traffic, offering greater cooling efficiency to allow the engine to run at cooler temperatures. The original brass-core radiators fitted during production were specified for the lower ambient temperatures and lighter traffic loads of the 1960s and 1970s, and modern UK driving, particularly slow-moving summer traffic, frequently puts those original radiators beyond their thermal capacity, while uprated and tuned engines generate more waste heat than the standard cooling system was designed to reject. Aluminium radiators with their larger core volumes and more efficient fin spacing dramatically improve cooling capacity.
Construction & Cooling Performance
Aluminium radiators are constructed with an aluminium core, a stack of tubes and fins, and aluminium tanks at each end, brazed together to form a single sealed assembly. While copper has a higher raw thermal conductivity than aluminium, a traditional copper-and-brass radiator uses lead solder to bond the fins to the tubes, which acts as an insulator and reduces the effective heat-transfer rate of the completed assembly, whereas an all-aluminium core is brazed throughout, eliminating the solder-joint insulation and allowing wider tubes and a finer fin pitch for greater surface area, typically delivering equal or greater heat rejection than the factory unit in the same installation space. The weight reduction is meaningful as well, an aluminium radiator typically weighing 40% to 50% less than the original brass unit, with the saving appearing at the very front of the car where it improves weight distribution and reduces the load on the front suspension, a particularly worthwhile benefit on the front-heavy six-cylinder MGC. The visual appearance from the front is similar to the original, presenting a comparable grille pattern, though the construction underneath is fundamentally different.
Application Coverage
Aluminium radiators are stocked for the principal classic-MG applications, hand-built in the UK to the original pattern as direct replacements. The MGB takes a specific aluminium radiator matched to its three principal system configurations, the early rear-fill arrangement, the centre-fill arrangement of the middle cars, and the late system with separate expansion tank, while the MGA, MGC, Midget, and MGB GT V8 each have their own specifications matched to the original mounting and connection arrangements, the MGA pushrod and Twin Cam radiators being separate non-interchangeable products owing to the Twin Cam's forward radiator position and remote header tank. Integral cooling fans and additional brackets can be specified as factory-fitted options at the time of order on some applications, and the original pressure cap arrangement is retained, so the correct cap rating for the specific car should be confirmed.
Installation & System Integration
Aluminium radiator installation is typically a direct replacement for the original, the new unit fitting into the original mounting brackets, accepting the original cooling hoses or modern silicone equivalents, and connecting to the original system in place of the unit being replaced. The cooling system should be thoroughly flushed before installation to remove any scale, sludge, or corrosion debris that has accumulated in the old radiator and the engine block water jacket, as old deposits circulating through a new aluminium radiator can block the narrower fin passages and accelerate internal corrosion where dissimilar metals are in contact. Supporting items typically renewed at the same time include the cooling hoses, the thermostat at the correct temperature rating, the water pump where it shows signs of wear, and the coolant itself, with Forlife or a similar coolant formulated for mixed-metal systems being the correct choice to provide long-term protection for both the aluminium radiator and the cast-iron block, and the coolant condition checked annually as inhibitor depletion is the main long-term threat to any aluminium cooling component. The complete package, aluminium radiator, fresh hoses, new thermostat, and refreshed coolant, transforms the cooling capacity of the car and substantially eliminates the temperature concerns that the original brass units sometimes cause in modern use.