Why are most vehicles still using water as coolant when surely cooking , ,heateror thin 'light oil ' would be more efficient , stable.and less corrosive on frost plugs etc.or is this question too silly.lol
daryl14,
Nov 26, 1:01am
Thermal efficiency - removing heat from your engine's oil and giving it up to the air flowing thru radiator. light oil would be crap at that.
Anti corrosion and other stabilisers added to anti freeze. Anything else is obviously not cost effective.
phalanax,
Nov 26, 1:10am
Really.seems to me oil would be more efficient at maintaining a constant working temp.less vulnerable to raised working temp fluctuations and could be cooled just as efficiently with a properly designed cooler.bonus is it can be recovered and recycled thus would be more environmentally friendly.doesnt a drill .drill better with the cooling of cutting oil as opposed to water.wouldnt water tend to cycle harden components thus promote quicker metal fatigue.not too mention the lower freezing and higher boiling points.lol .anyway.I spose it was a silly thought.
phalanax,
Nov 26, 1:10am
Really.seems to me oil would be more efficient at maintaining a constant working temp.less vulnerable to raised working temp fluctuations and could be cooled just as efficiently with a properly designed cooler.bonus is it can be recovered and recycled thus would be more environmentally friendly. doesnt a drill .drill better with the cooling of cutting oil as opposed to water.wouldnt water tend to cycle harden components thus promote quicker metal fatigue.anyway.I spose it was a silly thought.
daryl14,
Nov 26, 1:15am
Nope. Not silly. It's all aboot how fast the water can give up heat to it's surroundings.
Only thing that cools faster is something that is evaporating, water, alcohol or refrigerant. Or maybe hydrogen.
moosie_21,
Nov 26, 1:31am
Did you ever go to physics class!
a.woodrow,
Nov 26, 1:33am
there are coolants that have no water in them, forget the name but the advertise in petrolhead mag all the time
daryl14,
Nov 26, 1:33am
I Failed physics, but in this house Lisa, we obey the laws of thermodynamics!
phalanax,
Nov 26, 1:46am
Interesting a brine solution(saltwater).will cool things even faster than water (nearly twice as fast).yep your right about oil .it doesnt take heat away very well.
daryl14,
Nov 26, 1:47am
Ahhh and where did you learn aboot salt water cooling!
phalanax,
Nov 26, 2:00am
An article on quenching metal.lol.this assumes you have a bath of it though so i dont imagine it would stay cooler in a radiator circulation system.but apparently it draws heat away from metal quicker than water. maybe why boat engines are able to do what they do.
daryl14,
Nov 26, 2:04am
Decent sized boat engines have a secondary cooling water circuit so as to prevent salt water directly contacting engine which can corrode too easily.
Now we're headed for electrolysis territory. Careful now!
sr2,
Nov 26, 2:05am
Strange but true; water has a higher specific heat than oil.
pollymay,
Nov 26, 2:06am
Lots of boat engines use a thermal exchange unit and run standard coolant and water though the block. Essentially just like a car radiator but using salt water to cool the "radiator" instead.
sr2,
Nov 26, 2:09am
I think the reason why oil is better than water for quenching metal is that despite having a lower specific heat it has a far higher boiling point.
phalanax,
Nov 26, 2:12am
From what ive read .itpays to keep an eye on your coolant levels.as a certain amount of evaporation occurs and too much or too little water can cause failure.also it not unknown for some of this to escape the system as seals wear.water really is magical stuff.lol
phalanax,
Nov 26, 2:12am
From what ive read .itpays to keep an eye on your coolant levels.as a certain amount of evaporation occurs and too much or too little water can cause failure.also it is not unknown for some of this to escape the system as seals wear.water really is magical stuff.lol
curlcrown,
Nov 26, 2:15am
sr2 wrote: I think the reason why oil is better than water for quenching metal is that despite having a lower specific heat it has a far higher boiling point.[/quote
It's not the boiling heat that is pertinant but the amount of heat for a given volume that can be exchanged in a given period.
sr2,
Nov 26, 2:26am
Correct, it's called "specific heat" and because water has a higher specific heat than oil it is a more efficient coolant. (5th form physics).
petermcg,
Nov 26, 2:27am
In the case of the so called water cooled engine, actually water is not the coolant but just acts as a liquid in a heat exchanger,, its still the air that cools via Fan and radiator.
gs1220,
Nov 26, 3:14am
Some piston engined aeroplanes had alcohol as a coolant. Nuclear reactors have liquid sodium as a coolant.
meathead_timaru,
Nov 26, 4:20pm
No, it's the boiling point. If the cooling medium is flashing off as gas phase, such as water would do at over 100°C, the density of that medium immediately around the object is lowered and the cooling rate is lowered due to that. Also the cooling would be uneven potentially leading to cracking.
timmo1,
Nov 26, 4:35pm
The fact that you an endless supply of 'coolant' (i.e. the ocean) helps as well :)
daryl14,
Nov 26, 5:12pm
Wrong sorry dude, Cooling systems run at higher than atmospheric pressure to prevent boiling off. And additives in Antifreeze/antiboil further prevent it.
meathead_timaru,
Nov 26, 5:22pm
We're talking about quenching metals from a high temperature in atmospheric conditions using different mediums and the reason for the choice.
But since you brought it up, the maximum of 14PSIG pressure typically found in motor vehicle cooling systems only raises the boiling point of water to 120°C.
Since the public registrations are closed, you must have an invite from a current member to be able to register and post in this thread.
Have an account? Login here.