pro's and con's regarding external radiator side air dams for extra cooling

[RickB]

Hi all,

Whats the scoop on those external radiator air scoops that I see on so many older MCI's?

First of all, what is their exact title?

Obviously, they must lower engine operating temps but what do they do to fuel mileage?

Finally, where would one go about buying one?

Thanks in advance,
Rick

[JackConrad]

   Our MC-8 was equipped with these when we bought it. We removed them when we painted the bus and did a short trip without them.  We saw differnece in engine temps. We did re-install them (since we already had them).  Are they worth spinding the money to purchase them??  I am not sure. If you have overheating problems, you need to repair the problem, not apply band-aids.  Jack

[Ednj]

You can find them here = http://www.rm-fiberglass.com/bus/model/40.html

I thought about getting some to help pull in some hot air to help warm the radiators while driving.

Like Jack said fix the problem.
After installing new radiators, thermostats, hoses and just a good cooling system overhaul, you won't need them.

Radiator Air Scoops

[belfert]

I agree with Jack.  Fix any cooling system problems first before applying bandaids.

I was having cooling problems with my bus even with a four stroke Series 60.  I seriously considered venting the engine compartment door.  Finally, I took out the radiator and had it cleaned at a radiator shop.  The radiator shop rodded it out and found leak stop had been used due to pinhole leaks.  They offered the choice of closing off the bad tubes or a new core.  I choose the new core.

The new radiator core along with new water pump and thermostats fixed all my problems.  Only the steepest grade on I80 through Utah caused the temp to rise about 5 degrees above normal.  (195 is normal.)

[Lin]

There do not seem to be any "cons" listed, other than they are no substitute for thorough maintenance.  The same could be said for other devices like misters, etc.  Depending on the situation, I would still consider them.  We live in a desert so I tend to think that every advantage is worth looking at.  I would wonder though, at what speed they begin to help since you need the extra cooling most while climbing, and that is most likely to be done at low speeds.

[edroelle]

As everyone said, you want to fix problems first.  But MCIs are noted for their marginal cooling.   Over the years MCI has improved their cooling by going to larger radiators, larger fans, and smaller fan pulleys.  (Door seals and fans seals need to be good too.)

A number of years ago, Bus Trader magazine ran a test that showed the air scoops helped cooling. 

The air scoops can be one of the elements, to help keep your engine cool.

Ed Roelle
Flint, MI

[luvrbus]

Do you a poor mans wind tunnel test with yarn tied to the bus I know scopes do no good on a Eagle I did a test for Gary L a month ago and it was a dead space were he he wanted to install them, Richard at R&M will tell you they are for appearance mostly FWIW

[belfert]

I wouldn't be against adding air scoops, but make sure everything else is in tip top shape first.

[Lin]

Fred Hobe has instructions for making scoops on page 6 of his website.

http://users.cwnet.com/~thall/fredhobe6.htm

[buswarrior]

Fred Hobe has done some work with a fellow with the aeronautical background to do the math, and some seat of the pants experiments up and down the I75.

Note the much larger size of Fred's scoops, and how they come much further forward over the radiator opening.

For those who don't know, Fred has a turbo on his 8V71 and is closer to a military spec output in horsepower, so he needs a cooling system in top shape.

He might have been heard to call those small fibreglass ones "Mickey Mouse Ears" and from his work, are found to create a swirl of air that EXITS the radiator area, not drive it in.

One of Fred's later test scoops was actually being restricted by the blower fans at highway speed, (and he has the smaller pully on them!) and passed more air with the fan door open on his MC8!!! Took some nerve to run it with the fan door open, watching the temps rise, then start falling again, as the scoops did their thing.

As with many things, the return on investment required to continue the experiments wasn't worth it, since few of us will buy things, and would just copy the final product for free...

But if you want a set of those small ones, I've got a pair for $25!

happy coaching!
buswarrior

[HB of CJ]

Did very heavy duty cooling systems come from the factory?  Reason I ask is that, way back in 1970, we had some old MCI 35 footers with 8V71N's and 4 speeds that had been purchased used from some Nevada bus transit company.  Tona-paw to something or whatever.

The mechanics told us that the coaches had huge radiators and fans.  Anyway, the buses never overheated on us, even at 10,000 feet.  Yosemite Park and Curry Company.  Tioga Pass.  Years ago.  Ancient history.  Are we all getting really old here?   AUGGHHHHH! 

[Busted Knuckle]

Did very heavy duty cooling systems come from the factory?  Reason I ask is that, way back in 1970, we had some old MCI 35 footers with 8V71N's and 4 speeds that had been purchased used from some Nevada bus transit company.  Tona-paw to something or whatever.

The mechanics told us that the coaches had huge radiators and fans.  Anyway, the buses never overheated on us, even at 10,000 feet.  Yosemite Park and Curry Company.  Tioga Pass.  Years ago.  Ancient history.  Are we all getting really old here?   AUGGHHHHH! 

I have no idea about the coaches you ask about, but they could have been the start of standard larger radiators. Also a manual transmission bus will always run cooler than an automatic if all other conditions are the same.
#1) Manual transmissions do not generate near as much heat as automatics.
#2) Automatic equipped buses actually use the engines cooling system to also cool the transmission!
#3) Manual transmissions are more energy efficient than automatics, which means less loss of horsepower to the wheels.

FWIW   BK 

[Lin]

BK,
     Yeah, but you have to shift that manual.  With the automatic, you can just put it in gear and go make a sandwich.

[RickB]

I am such a wimp when it comes to operating temps. I turned around at the first major pass in Colorado because my temp gauge reached just shy of 200 degrees. I think Brian Diehl wanted to give me a good swift kick in the rear rend!! If it is above 85 outside and I drive my bus with the air on or the toad behind I approach 190 so I certainly don't think I have a system failure, it's more of an operator failure...  and I must admit, right or wrong, two things I will probably never get used to:
Holding my throttle wide open and anything over 180 degrees.

I was wondering if the air sccops would provide just a little more cooling without ruining my already poor 6-7 mpg. I read that our mirrors are worth over a mile per gallon, so I assume that these scoops have to be pretty inefficient as well. Has anyone ever given any thought to putting a couple of inexpensive side aimed cameras mounted inside aerodynamic housings on the outside of their bus feeding a couple of screens in the dash area to eliminate mirrors entirely?   Just a thought...

[Ednj]

I read that our mirrors are worth over a mile per gallon, so I assume that these scoops have to be pretty inefficient as well. Has anyone ever given any thought to putting a couple of inexpensive side aimed cameras mounted inside aerodynamic housings on the outside of their bus feeding a couple of screens in the dash area to eliminate mirrors entirely?   Just a thought...

Bill has them on his Eagle.
Hard to see in this picture but they are there.