The cooling system in the Classic Mini has used the same basic style radiator since its beginning in 1959 up until the introduction of the twin point injected cars when the radiator was moved to the front of the car.  The original Mini was powered by an 848cc engine and designed for the little back roads of the UK.  The cooling system demands were nominal.  As engine capacity and performance demands increased so did the need for more efficient cooling.  All of this had to be accomplished within the limited design space allowed for the side mounted radiators with production cost being a key factor. (even Plastic header tanks can be found on late model Minis!)

With the closing of all real factory capacities, the aftermarket industry came to the rescue first with the introduction of modern production technique for manufacturing and then with improved flow and performance.   Having built Minis for the last 35+ years and installed them in both street and race cars, I thought I would share my experience. While the chart below is based on the use of the early 2 piece radiator, the one piece shroud simply makes it a little easier but has no effect on cooling.

  Radiator options for all Minis      
             
Part # Style Looks Ease of Fitment Capacity Cooling Price
             
ARP2000 Stock 3-core 3 3 3 2 3
C-ARA4442 Super 2-core 3 5 3 3 3
C-ARA4444 Super 4-core 2 3 4 4 4
ARC1106 Stock 2-core 4 5 2 1 5
C-ARA4443 Late Super 2-core 3 3 3 3 3
C-ARA5000 Super Alloy 5 3 4 5 5
             
  On a scale of 1 to 5, 5 being the best!      

Click here to see full parts diagram for the Mini cooling system