Mist Cooling

ReycleBill

ReycleBill

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Ever heard of evaporative cooling? It's not used very often here in North Carolina but in the Southwestern US, evaporative cooling is the trick. MisterCycle http://mistercycle.net/ sells a mister kit for motorcycles that is designed to cool the rider but I was wondering if anyone has ever tried evaporative cooling (misting) as a way to help cool an air cooled motorcycle engine.

Misting systems are sold for buses and trucks. They work by misting the radiator and/or the air in front of the radiator. It appears that cooling the air in front of the radiator is more effective in dry climates but misting the radiator itself is more effective in humid climates.

Something like this seems like it would be pretty easy to build with an automotive windshield washer pump, some copper tubing, a thermostatic switch and a few odds and ends. And being that I've got a brand new still in the box, Hyundai windshield washer pump I thought I just might give it a try.

Now to be clear, I am talking about using the misting system as sort of a back-up cooling system for those 100 degree days when the regular cooling system can't seem to keep up. I don't know about the rest of you but when it's 100 degrees or thereabout I notice my XS isn't its usual perky self.

Any thoughts, positive, negative or otherwise?
 
I have had my hand in the "misting fans". The ones that I worked with used something like a 1,000 psi pump. I don't think your washer pump is going to cut it. Do you a nozzle in mind to do this? You have to form a very fine mist in order for it not to wet the surface and with the humidity we have on the east coast you really can't use them effectively. They did work for "spot cooling" I think we got a 10-15 degree drop in temp.
 
generallee said:
I have had my hand in the "misting fans". The ones that I worked with used something like a 1,000 psi pump. I don't think your washer pump is going to cut it. Do you a nozzle in mind to do this? You have to form a very fine mist in order for it not to wet the surface and with the humidity we have on the east coast you really can't use them effectively. They did work for "spot cooling" I think we got a 10-15 degree drop in temp.
Click to expand...

I too, am wondering about pressure requirements. As for the nozzle I'm thinking of making my own.

10-15 degrees-- while not the 40 degrees that can be expected in a drier climate-- could be the difference between frying and engine or riding all summer long.

I wonder if wetting the surface is an issue when you're talking about metal and not skin? Spraying water on the outside of a car radiator is a safe and effective way to cool an overheated engine.
 
I used to run a Devils Own water injection system on my Turdbod Honda to drop the knock ceiling so that I could run higher boost levels on pump gas, and its cool for certaint applications, but i'm not quite sure how it would work on a carbed setup.

And... after thinking about it for a second, i'm not sure it would be worth the trouble on a XS650. I can't imagine there would be any significant performance gains. Another thing is that you have to tune for it too!
 
TurboBully said:
I used to run a Devils Own water injection system on my Turdbod Honda to drop the knock ceiling so that I could run higher boost levels on pump gas, and its cool for certaint applications, but i'm not quite sure how it would work on a carbed setup.

And... after thinking about it for a second, i'm not sure it would be worth the trouble on a XS650. I can't imagine there would be any significant performance gains. Another thing is that you have to tune for it too!
Click to expand...

I don't think you understand. I'm not talking about water injection, I'm talking about engine cooling done entirely on the outside of the engine.

By the way, water injection has been used on carbs for 50+ years to reduce spark knock.
 
We are also talking about water cooled vs air cooled engines. Surface temps are cooler on a water cooled engines even on radiaters. I'd be worried about thermal shock (cracking) spraying an air cooled engines hot spot. Maybe I worry too much...
 
Bill I may have some nozzles from the fans I was using if I can find them I'll send them to you if you want them. They are stainless with like a 1/8th outlet on one end and a outlet the size of a hair on the other. They also come apart so you can clean them out from mineral build up.
 
I may have misread... :laugh:

I guess the question then is would there would be any advantage over running an oil cooler?
 
It isn't just the engine heat that makes the bike sluggish on hot days. The air itself is less dense, meaning less oxygen is available for combustion.
 
azman857 said:
We are also talking about water cooled vs air cooled engines. Surface temps are cooler on a water cooled engines even on radiaters. I'd be worried about thermal shock (cracking) spraying an air cooled engines hot spot. Maybe I worry too much...
Click to expand...

I wondered about the same thing but riding motorcycles in the rain never seems to cause any such problems.
 
generallee said:
Bill I may have some nozzles from the fans I was using if I can find them I'll send them to you if you want them. They are stainless with like a 1/8th outlet on one end and a outlet the size of a hair on the other. They also come apart so you can clean them out from mineral build up.
Click to expand...

I'll keep that in mind. Thanks!
 
Ghetto said:
First I've seen of this. I wonder if it get's your glasses all wet. That would bug me.
Click to expand...

I sure wet glasses aren't much of a problem in the Arizona desert but here in the Carolinas where we live with 90% humidly I share your concern. But since I'm talking engine cooling then maybe it's not a problem.

Then again, it might put the rider in a steam bath, especially when sitting at a traffic light.
 
I've run a home made water injection system on my supercharged Miate since 1997. It uses a windshield washer pump and a spray nozzle cut from a pump spray bottle, the kind cleaning products use. Distilled water must be used or huge mineral build up will result.

I'd think about running the spray through the engine. 100% of the cooling water would be used and a bit of steam cleaning of the carbon would happen. Use a normally off switch like a horn button and just give a very short blast when the engine needs it. position the nozzle so it sprays toward the carb mouths.

Tom Graham
 
I find the thought of H20 injection more interesting than misting the outside of the motor, which I think has too little surface area to make a significant difference in performance. And even at that... or maybe i'm just not well versed in H20 injection, but when I used h20 injec. on my car, i had the advantage of tunable EFI.

Tom, i'm not sure what kind of setup you're running on your miata, but i'm sure you know that H20/denatured alc have the same/similar effects as race gas, you need to more total timing and much less fuel when spraying since a large majority of the fuel is no longer used as thermal management on boosted setups. I have no idea how the carbed guys did it, and i'm not sure i'd use h20 injection on a naturally asperated - low compression engine like the xs650.
 
90 percent humidity, 100 degree temps. Stay home in the ac and ride at night.
Leo
 

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