Mini World – July 2019

[ Cooling system ]

64 July 2019 MiniWorld

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Fitting a high quality alloy radiator to a modified Mini can further

improve cooling and they look great in an engine bay.

Oil coolers were fitted as standard to Cooper S models and 1990

RSP Rover Mini Coopers. Once a popular modification, today they

are normally only fitted to highly-tuned Mini engines as they are

often seen as overkill.

Antifreeze should be renewed every two years. Use the correct

type at 33% antifreeze concentration under normal UK summer

and winter conditions. See the table and further info below.

Filling or topping up coolant is made so much easier with a

funnel. They are inexpensive and help to keep the engine bay tidy

by preventing splashes and spillage of coolant.

Water expands by approximately 9% when it freezes, which is more

than su cient to cause considerable engine damage. Therefore, adding

the correct type of antifreeze to your Mini’s cooling system, in the

correct proportion for the part of the world in which you live, is very

important. It is also important as antifreeze helps prevent corrosion

and adds lubrication to the coolant. There are three main types of

antifreeze; IAT (Inorganic Additive Technology), OAT (Organic Acid

Technology) and HOAT (Hybrid Organic Acid Technology). From the

user’s point of view, the main di erence is the length of time before

the coolant requires changing. This is, in order: two years, fi ve years

and fi ve-plus years, some manufacturers state up to 10 years.

All A-series and A-plus-engined Minis, and indeed most older cars,

require IAT (Inorganic Additive Technology), which should be changed

every two years. Di erent types of antifreeze are di erent colours,

and usually IAT antifreeze is blue in colour, but this may not always

be the case with all manufacturers so it is very important to check.

IAT antifreeze is not as common on the shelves of accessory shops

today and may take a li le searching out. It is worth pointing out that

some retailers recommend the wrong antifreeze. Traditionally, the

best-known antifreeze for Minis is Bluecol and many slightly more

mature readers will remember the Bluecol stickers that were commonly

applied by garages to the windscreen or in the engine compartment.

Luckily, Bluecol is still available today and is stocked by Mini Spares.

An alternative to antifreeze is Waterless Coolant, available from Evans,

which has performed well in a MiniWorld project car. Evans claims that

it reduces cavitation erosion by 75% when compared with water-based

coolants and eliminates oxidation corrosion. It lasts over 20 years and

a million miles in service without the need for replacement. It has 75%

less vapour pressure than water-based coolants and it is biodegradable.

It has a boiling point above 180°C, thereby eliminating the risk of

overheating and, at the other end of the sale, it goes down to -40°C.

Traditional antifreeze concentration:

The table below shows how much protection is

given by di erent quantities of anti-freeze.

ANTIFREEZE: WHICH TYPE AND HOW MUCH?

Antifreeze Starts freezing Frozen solid

% °C °F °C °F Pint Litre

25 -13 9 -26 -15 1.5 0.85

33.3 -19 -2 -36 -33 2 1.18

50 -36 -33 -48 -53 3.25 1.18