Make you own coolant

[drmotorsport]

Inspired somewhat by the screenwash thread, got me thinking could other liquids be used for coolant? I assume water with a slurp of antifreeze was arrived at as a solution cos it's cheap and readily available, but could a light oil, or petrol be used as a thermal energy transfer medium?

[shalmaneser]

drmotorsport said:

Inspired somewhat by the screenwash thread, got me thinking could other liquids be used for coolant? I assume water with a slurp of antifreeze was arrived at as a solution cos it's cheap and readily available, but could a light oil, or petrol be used as a thermal energy transfer medium?

Pretty much any liquid can be used as coolant, in a lot of rockets the nozzle is cooled by fuel. But as far as liquids go water has really excellent thermal properties and doesn't explode when it gets hot or leaks.

Please don't put oil or fuel in your radiator.

If you want to use something other than water there are various waterless coolants around, but none of them are better than water, and there's not much cheaper.

[JohnCarlisleApeiron]

What about a nuclear inspired solution? Sodium has fantastic heat transfer properties. Could take a while to warm through, especially on an older diesel. Just don't get your filler caps mixed up with the wash bottle.

[Panamax]

JohnCarlisleApeiron said:

What about a nuclear inspired solution? Sodium has fantastic heat transfer properties.

Some cars have sodium cooling in their exhaust valves - including the Kia Stinger.
https://www.youtube.com/watch?v=onpyNFKGEYQ
It's about 2 minutes into the clip.

[Super Sonic]

Pretty sure it's a sodium alloy, as pure sodium is corrosive. Whasnt there a Fiat or Lancia with a Ferrari engine that had sodium valves that corroded from the inside and fell into the cylinder?

[Tye Green]

sodium filled exhaust valves were also fitted in cosworth YB engines

[Evoluzione]

I can't imagine why you would when you can buy good stuff off the shelf for decent money.

[donkmeister]

Tye Green said:

sodium filled exhaust valves were also fitted in cosworth YB engines

And the Vauxhall Vectra with the Z28 engines.

[donkmeister]

drmotorsport said:

Inspired somewhat by the screenwash thread, got me thinking could other liquids be used for coolant? I assume water with a slurp of antifreeze was arrived at as a solution cos it's cheap and readily available, but could a light oil, or petrol be used as a thermal energy transfer medium?

In an emergency, I've known people to pee in the radiator. No idea if that is particularly corrosive to engine innards.

Silicone oil, used for transformer cooling? I know that people have immersed PCs in it for cooling. Could possibly use that instead of water in a loop cooling system in a car.

In the 90s didn't they find the French had a habit of using ethylene glycol to sweeten wine? So perhaps some old French wine would do.

[Krikkit]

The problems are numerous, because actually water is very good at everything.

1 - Good heat capacity to ensure effective cooling
2 - Reasonably low viscosity that isn't highly variable with temperature changes between -20 and +120°C
3 - Non flammable in case of leaks (at least below 800 degrees or so)
4 - Preferably evaporates cleanly when spilt on tarmac, in case of leaks
5 - Cheapish as we need a few litres of it

Not an easy list to come up with! The usual waterless coolants are ste compared to water with enough glycol to stop it freezing.

[donkmeister]

Krikkit said:

The problems are numerous, because actually water is very good at everything.

1 - Good heat capacity to ensure effective cooling
2 - Reasonably low viscosity that isn't highly variable with temperature changes between -20 and +120°C
3 - Non flammable in case of leaks (at least below 800 degrees or so)
4 - Preferably evaporates cleanly when spilt on tarmac, in case of leaks
5 - Cheapish as we need a few litres of it

Not an easy list to come up with! The usual waterless coolants are ste compared to water with enough glycol to stop it freezing.

I could be wrong, but isn't the viscosity of water at -19 C somewhat different to the viscosity at +19 C, and different again at +119 C?




(I realise you are talking about ethylene glycol solution under pressure of course )

[Krikkit]

Of course

[drmotorsport]

Interesting stuff folks. Water seems to be the go to substance in the real world. Naturally I'm not going to rock up at Shell and pump 8 litres of VPower in my expansion tank. I was thinking of a hypothetical alternative to water/glycol in a standard automotive cooling circuit and assuming I don't care about leaks or their consequences!

[PhillipM]

Water is an amazing cooling for the temperatures you're operating at with an engine, almost anything else you can use is a downgrade.

[shalmaneser]

PhillipM said:

Water is an amazing cooling for the temperatures you're operating at with an engine, almost anything else you can use is a downgrade.

Exactly, and you'll not find many cheaper liquids.

[Boosted LS1]

PhillipM said:

Water is an amazing cooling for the temperatures you're operating at with an engine, almost anything else you can use is a downgrade.

Does it boil around the valve seats, if so you need something that doesn't as that's a high risk area.

[InitialDave]

donkmeister said:

Tye Green said:

sodium filled exhaust valves were also fitted in cosworth YB engines

And the Vauxhall Vectra with the Z28 engines.

Didn't Metro Turbos have them?

[lufbramatt]

Lots of ww2 aero engines had sodium filled valves. Think the idea has been around since the 1920s.

Iirc the KR engine in the mk2 Golf GTi 16v had them.