Radiator Mister

[RJ]

Gary -

One of the major reasons busnuts have to install mister systems on their coach's radiators is because it's easier than taking all the excess weight out of their right shoe.

FWIW & HTH. . .

[belfert]

One of the major reasons busnuts have to install mister systems on their coach's radiators is because it's easier than taking all the excess weight out of their right shoe.

Could these coaches when new be able to be driven at full throttle up a steep grade without overheating?  It seems to me that on some grades you're going to need just about every bit you can get out of the engine just to stay moving at above a walking pace.

[usbusin]

The secret is to select a gear where you are not using "full throttle".  This may not be as fast as you want to climb the hill, but you must be at "partial throttle".  Selecting a lower gear will give you the torque you need to climb the grade. 

It is torque not horsepower that will get you up the hill.  Your transmission is a "torque multiplier".  Running the engine on a partial throttle will keep the engine from overheating. 

Try it sometime.  It worked on my 4104.  You could climb almost any hill in 2nd gear at 28MPH and she loved it!  Did I want to go faster, yes.  But, I wanted to get to the top of the hill!!

GaryD

[Len Silva]

Everyone pretty much agrees that misters are a Band-Aid approach, and with a cooling system in good condition and good driving techniques, you should not need them.

If, however, you do use a mister system, I would caution you to use a dedicated water supply filled with distilled or de-ionized water.

I tried a mister on my home air conditioner with dramatic savings, it dropped the run amps by 40% but destroyed the condenser in about 5 months with calcium build up.

[Red Rider]

FWIW, I just removed my misters on the 4106. I live and operate pretty much in the mountainous West or the desert in the Las Vegas area so heating can be a problem. I second the suggestions that are posted here. Last summer I made two trips to Yellowstone NP. and over to Cody and back to southern Utah. I had a friend running along with me who drove a 4106 for 15 years and he coached me through the very thing talked about here. High RPM  is truly the key. We went through a lot of work putting in the dedicated water lines and a separate pump only to find that I never used it. I did find out however that my Temp gauge was telling me fibs. A new dash unit AND new wire took care of that problem.

[TomC]

I created a 15 head mister from Home Depot patio misting system connected to my water system through a 12v solenoid.  It worked OK, but wanted more.  I drilled out the bottom two misters with 1/16th" drill and aimed them up.  Now we're talking enough water that cools the engine in a matter of a couple of minutes.

One other thing that makes a difference, make sure your radiator is sealed well against the hot air recirculated back through.  I use Gorilla duct tape to seal the edges.  It makes a noticeable difference.

Yesterday climbing west bound I-40 from Needles in 90 degree weather, I took it easy at 43 mph (second gear [V730] at 2100rpm) and ended up at the top (which is the steepest part) at 195 degrees without the misters. Good Luck, TomC

[luvrbus]

90 degrees Tom you had to do it early was 108 at 4 pm lol

good luck

[garhawk]

Hey Tom:

Glad you brought up the point of sealing around the radiator to stop recirculating hot air.  That very suggestion was made to me by Ron at Eagle's Nest in Nashville only a few days before I installed the mister.

First off, here is the layout and dimensions of my radiator and intercooler.  The radiator measures 42" wide X 18" high. The intercooler measures 40" wide X 13" high and is mounted directly on top of the radiator.  The radiator also cools the generator so, a 17" diameter fan is mounted in front of the radiator on the left half to blow air through the fins.  This setup keeps the generator within it's temperature comfort zone when the bus engine is not running.  However, the small fan also runs any time the big engine is fired.

The mister tube (described in my original post) is mounted across the width of the radiator at it's top and sprays downward.  It would be a simple job to drill holes 180 degrees from the existing spray openings to 'mist' the intercooler - what you think?  Of course, that is a might premature until the present setup is tested.

Before installing the mister, I closed up all the openings surrounding both the engine and intercooler radiators.  Previously, (using all my Thomas Edison scientific skills - thanks Ooronjay) I had hung a towel out front of the radiator screen and, with the engine running at fast idle, the fans had pulled the bottom of the towel up against the door screen.  Once the closure pieces were installed, the same circumstances yanked the towel off it's holder and flat against the screen!  The openings surrounding the radiators had been approximately 6" on the left, 2 1/2" on top and, 4" to the right - they made a marked difference in the airflow!

Of course, the fan shroud is circular and on the engine side of the radiator which omits the pulling of air through the corner areas of the radiator.  In my mind, now that the surrounding openings are sealed off, the spillover effect from the big fan pulling more efficiently should cover the corner realestate to a greater extent.

With all this said (and it probably should have been mentioned before my original post) my point is that closing up the openings certainly made an obvious difference in the airflow.  So, without removing the closure pieces and testing the mister on it's own, my report to you later will be somewhat tainted.  It just could be that the additional cool air flow will suffice but, if not, I plan to turn on the squirter!

[lvmci]

Hi All, when I was a kid, driving to LA or back to LV, my Dad (along with most other desert drivers) would hang this canvas water bag in front of one side of the radiator filled with water, it worked like an evaporative cooler on the radiator. That was in the 50's and into the 60's when radiators started to get bigger and better. Maybe it should be looked at as augmenting the built in cooling system. Yankee inginuity, post WW2 also gave us thewindow hanging swamp coolers here in the southwest. Short term fixes, that lead to a longer engine life and more comfortable ride, lvmci...

[Tim Strommen]

Hi All, when I was a kid, driving to LA or back to LV, my Dad (along with most other desert drivers) would hang this canvas water bag in front of one side of the radiator filled with water, it worked like an evaporative cooler on the radiator.

Hmm, makes me think of modern commercial evaporative cooling systems (as did the initial comment about using a stream of water and thus soaking the radiator).  Perhaps a holding membrane in front of the radiator/intercooler like one offered by Evapco (no stake/relationship with them).  It's likely that if mineral laden water was sprayed onto a holding membrane, any build-up should end up on the membrane, and not eat the radiator core.

Makes me want to put my money where my bus is for another cooling experiment... 

-Tim

[Lin]

I suppose, for that matter, one could use the same medium as is used on swamp coolers.

[skihor]

Hi All, when I was a kid, driving to LA or back to LV, my Dad (along with most other desert drivers) would hang this canvas water bag in front of one side of the radiator filled with water, it worked like an evaporative cooler on the radiator.

Hmm, makes me think of modern commercial evaporative cooling systems (as did the initial comment about using a stream of water and thus soaking the radiator).  Perhaps a holding membrane in front of the radiator/intercooler like one offered by Evapco (no stake/relationship with them).  It's likely that if mineral laden water was sprayed onto a holding membrane, any build-up should end up on the membrane, and not eat the radiator core.
In humid weather it simply doesn't work. Putting the water ON the radiator gets rid of way BTU'S than trying to cool the incoming air.

Don & Sheila

Makes me want to put my money where my bus is for another cooling experiment... 

-Tim

[Geoff]

I installed a radiator water spray system in my bus for pulling hills with my toad or trailer, and it is the only way I can make it without overheating and having the bus temp shut -down system kill the engine.  I'm okay with the stock radiator if I'm not pulling anyting, but the trailer/toad is too much for my cooling system.  And, I have been doing this for the last 6 years and have no calcium build up in my radiator.

P.S.  I used adjustable garden sprayers, not patio misters, so I get lots of water on the radiator and it cools down very quickly with a few 5 second sprays.  Gearing down is not going work for me.

[garhawk]

Hello Mr. Long,

Thanks for your comments concerning the mister system I installed in the Eagle model #20.  Your determination that the system is a bandaid may or may not be correct.  Your thoughts are shared by some very well respected wrenches in the business.   We'll know more in about six weeks as my brother, sister-in-law, my wife and I are about to embark (in seperate buses) on a western adventure into the high mountains and hot plains.

I'll give my best effort to the correct driving procedures, including a light foot and the imigination that the throttle is an egg. 

I have sought and followed professional advice as to the maintenance of the cooling system.  That has included shrouding around both the engine and intercooler radiators,  along with the everyday attention to fluid levels, thermostat, cleanliness, etc.

Twenty five years in the bus industry without one heat related shut-down is an impecable record Mr. Long.  How many of those were in an Eagle estimated to weigh 45,000 pounds with a 525 hp engine shoehorned into an opening sized for a much lesser powerplant and transmission of which the origanl engineers had not even dreamed?

Perhaps before condemning us old, financially limited, Thomas Edison wannabes to the "...simple..." category, you should give us the opportunity to try our hands at homespun engineering. 

If I can believe some of my fellow busnut engineers (and I do, both downtown and backyard varieties) the misters work in the situations for which they were intended - that being temporary, potentially high heating circumstances, that are short lived or, the water runs out!

[Geoff]

Bump.  I can't believe what I read when what I do WORKS!

I installed a radiator water spray system in my bus for pulling hills with my toad or trailer, and it is the only way I can make it without overheating and having the bus temp shut -down system kill the engine.  I'm okay with the stock radiator if I'm not pulling anyting, but the trailer/toad is too much for my cooling system.  And, I have been doing this for the last 6 years and have no calcium build up in my radiator.

P.S.  I used adjustable garden sprayers, not patio misters, so I get lots of water on the radiator and it cools down very quickly with a few 5 second sprays.  Gearing down is not going work for me.