LAND ROVER WORKSHOP Using Evans Waterless Coolant
No water, still cool TO SEE HOW EVANS WATERLESS COOLANT FARES IN THE ENGINE OF A CLASSIC AND TO GET AN IDEA OF THE WORK INVOLVED, WE’VE HAD ONE OF OUR STAFF RANGE ROVERS CONVERTED.
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ANY READERS WILL be aware of Evans Waterless Coolant. It has been advertised in Land Rover World and at large events over the past year or so, and it is being stocked by retailers such as Devon 4x4 and Nene Overland. As the name implies, Evans is not a traditional water/anti-freeze mix, but a blend of proprietary non-toxic chemicals, none of which are conventional H2O. Evans claims several advantages for its coolant. The main one is that, because it’s not water-based, Evans coolant doesn’t boil at 100°C. Various blends of the coolant are available with different boiling points but the standard Evans Classic boils at 180°C (versions with higher boiling points are available for racing use). Although water is a very effective coolant
BY JACK GROVER when in its liquid state, when it boils and turns to steam the efficiency of the system is greatly reduced. Most systems rely on building up a slight pressure to raise the boiling point of water above 100°C to prevent the formation of steam. However, it’s still possible for localised pockets of steam to build up at hotspots in the engine – especially around the cylinder head where localised boiling takes place – which reduces the effectiveness of the cooling system at the very places where it’s needed most. The pressure in a system with conventional coolant also places more stress on hoses and other parts. Because Evans Coolant doesn’t boil until 180°C there is no steam or pressure build up, and because it doesn’t contain water
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there are no on-going corrosion worries – the coolant contains a corrosion inhibitor but it doesn’t need regular changing like conventional coolant. Because of the higher boiling point Evans claims that its coolant remains more efficient at drawing away heat in all situations than water. To see how Evans Waterless Coolant works in an older car we had this 1992 Range Rover Vogue converted to Evans Classic 180 coolant. The work was done by a two-man team from Evans, including the company’s chief engineer John Priestly, and we borrowed some garage space from Nene Overland for the job, which took just over an hour. Although we were having the conversion done for us, Evans says that the process can be completed by the home mechanic. The only pieces of equipment needed are basic tools to drain the cooling system and access
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LAND ROVER WORKSHOP Using Evans Waterless Coolant
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Draining the coolant in the usual way – by slackening and removing the bottom hoses from the radiator.
Collecting the old coolant means you can see how much has been drained and how much is left in the system.
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to compressed air to help purge the system. Evans can also supply step-by-step guides tailored to many different car and engine types to help owners do the job themselves. Ideally you’d have enough drain tub space to hold all the old coolant too, as the first step is to drain as much of the system as possible through the radiator bottom hoses. If you know the capacity of the cooling system and how much you’ve drained, you’ll know if there is any of coolant left in the system. This is where the compressed air comes in – once the system has drained via gravity, you stick the air line in the header tank, seal the filler with a rag and pressurise the system, which forces a lot of the water that’s collected in the system’s low points through to the bottom hose to drain. As well
as the header tank itself our Range Rover had plugs on top of the radiator and at the system’s high point on one of the heater hoses – these were removed and the air applied here too. Evans also suggests removing the drain plugs for the block if the car has them. The Range Rover has two (one on each side, under the exhaust manifold) but after 21 years and with awkward access neither would budge. Since persevering could lead to breaking the plug or even stripping the thread in the block it was wisely decided to leave them be. Since they couldn’t be sure of getting all of the water out of the block, the chaps from Evans said that they may need to give the system an extra flush. Fortunately they have
a way of telling exactly how much water is left in the system with a handy gadget that measures the coolant’s refractive index – essentially shining a light through a sample and measuring how clear (or not) it is. The less clear the sample, the less water content there is. Our Range Rover’s original coolant had an almost perfect 50/50 mix of water and anti-freeze. Having replaced all the loose hoses and clips – the conversion is a good time to check all of these and replace any damaged items, especially as, once converted, you hopefully won’t be draining the system again for a long while – the system is then filled with a preparation fluid, which is essentially the same as the final waterless coolant but without the rust inhibitors and stabilisers. It
Ideally the block should be drained through its own plugs. In many cases the access isn’t great.
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The system is refilled with a prep fluid…
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A compressed air line is used to pressurise the system through the header tank to force out the coolant.
…and the engine is run at a fast idle to circulate it through the system…