Evaporative cooling water spray - any good?

[John E Davies]

I have been wondering if a water spray system on the front bumper would be of any benefit in keeping the temp down on long mountain grades while towing my trailer. I normally don't have any trouble with overheating, and i don't want to install hood vents. (I am NOT talking about water injection into the intake manifold.)

Is such a system practical for ocassional use?

How much water capacity would be needed for it to run about 10 minutes?

Has anyone messed around with this? I understand the Land Rover guys sometimes use these squirters.

Any links?

Thanks.

John Davies
96 LX450
Spokane WA USA

 

[cruiserdan]

It would certainly cool things down. The main problem would be having enough water available to do the job effectively.

 

[mtycruiser]

I don't have any experience in doing this on a vehicle to cool the engine, however, having grown on a hot and dry climate I have some experience with evaporative cooling in houses.
I suspect that not too much water is needed, just some "mist" like what they put on the looooong lines at places like "Six Flags" as the mist reaches the radiator and evaporates, it will "pull" heat from the radiator, helping to cool it down.
For your aplication, trial and error will be the route as far as placement and amount of water required.
Just my $.02

 

[ELLTEE]

Uh, I doubt it.
Evaporative cooling works (try sitting at an outdoor bar in Palm Springs in August!!), but the water has to have a chance to evaporate before it blows away!
Perhaps if you had some way to soak the rad itself, like those old canteens with the ugly horse-blanket looking material on the outside that you could wet to cool the water inside. But that would probably reduce your heat transfer from the rad when it was not wet.

Good thought, though!

LT

 

[hoser]

Water spray systems have worked well on intercoolers. Most people just replumb their windshield washer system. The water capacity you would need would be dependent on the flow rate and number of sprays. You can even wire it up so that it sprays when the engine reaches a certain temperature.

Sounds like a bandaid though.

Here's an intercooler spray kit

 

[Steve C]

Here's my guess. Toyota, in all likelyhood, designed the radiator based on what they thought the highest output of the engine should be at a high operating temperature. So, while you could increase the heat transfer by allowing water to make a liquid to vapor state transition on the surface of the radiator, this may allow a long term power output greater than what Toyota envisioned.

While that may not be that bat of a thing, it may allow the oil temperature and transmission fluid temperature to increase. For this reason, if you do try this type of thing, I would look at geting some sort of temp gauges for oil and trans fluid.

All just opinions, of coarse.

 

[robbie]

Do any of you remember the old pictures of old vechicles with those rough woven water bags in front of the radiators in some of the old movies. Well these provided this type of vapor to cool the radiator in the desert back in the not too distant past. I do think a small one of these in front my help, if you keep it far engouh in front of the radiator so it could still pull air aournd it when the fan kicked in.
But I have only heard of the misting systems for the intercooler for turbo racing, etc.
later robbie

 

[John E Davies]

Thanks for the comments - it looks as if this is pretty much theory at this time.

Elltee: "Uh, I doubt it.
Evaporative cooling works (try sitting at an outdoor bar in Palm Springs in August!!), but the water has to have a chance to evaporate before it blows away!"

Don't you think the water would pretty much vaporize instantanteously when it hits the hot radiator? I don't think there would be any liquid actually getting through the cooling fins.

Hoser: "Most people just replumb their windshield washer system.

I think a seperate tank makes a lot more sense - then you won't use up the bug spray. And I think dumping washer fluid on the radiator isn't a great idea.

Steve C: "it may allow the oil temperature and transmission fluid temperature to increase."

Good point. If the water spray were directed at the tranny cooler, the ATF would cool also. I suppose one could mount an oil cooler as well, and squirt that.

I'm not especially interested in experimenting. I was hoping someone had hands-on experience with evaporative cooling a Land Cruiser. It's interesting to think about tho.... I only have experienced one instance of overheating - the outside temp was around 100 degrees and the grade was looooong and steep. I will service my fan clutch and see if that helps - the rest of the system is clean and working fine, and the radiator is new.

John

 

[mot]

I found this shop offering exactly what you were thinking about here (not a very good site, with Japanese, too):

Maybe halfway down, you can see two nozzles spraying. They don't have any more details, other than its cost. If what I've read in a magazine is correct, it "supposedly" lowers the water temp by 20 degrees (Celsius) in two minutes or something.

Sorry that I don't have any more information.

Anyway, here is the link:
http://www.machiyama.co.jp/news/saisinnnews.html

Also I've just found this guy doing it with his Z. Here is a pic of it in action:
http://www.asahi-net.or.jp/~tq6n-ymd/splay2/05.jpg

How he's done it:
http://www.asahi-net.or.jp/~tq6n-ymd/splay.html

Additional stuff:
http://www.asahi-net.or.jp/~tq6n-ymd/splay2.html

Some more stuff, I think:
http://www.asahi-net.or.jp/~tq6n-ymd/splay3.html

So it seems that it is possible.

He's added a thermostat/water temp gauge that's pretty clean, too:
http://www.asahi-net.or.jp/~tq6n-ymd/temp.html

Good luck!

Mot