MCI 7 extra radiators

[edvanland]

My MCI 7 with 8V92 and 740 auto still has a heating problem on long climbs in Arizona, or any mountains.  So far I have had new thicker radiators with baffles put in, I did that what a pain, smaller fan pulley, squirlle cages taken out and cleaned, new 170 degree thermastats, new hoses, new seals around the squirrle cages, scoops at the rear of the side intakes, and also a mister system put on. I also put in a 5 gal puke tank to recover the water.  I also run with the rear doors open on long climbs, which helps a lot to let the hot air out. I haven't  found how the trans is cooled, don't know what I am looking for.  Wondering also about a different trans cooler set up.
Was thinking if there is a way to put two more radiators below the two existing radiators.  I have the lower louvers on each side door and a lot of room.  Was thinking of making brackets so the radiators could be swung out to get to the engine.  Course would have to put in electric fans on them also.
Any thoughts on if fessiable and how to plumb them and would it work?
Thanks
ED
MCI 7

[ceieio]

Ed - my MC7 has a third radiator mounted on the right side low with an electric fan on it that helps some on cooling (the fan really needs to be better than the one I have).  I have the R & M kit on the bus and the side access panels have openings cut into them that let air in.

I can see the temprature drop a couple of degrees when I turn that fan on when climbing.  I will take some pictures for you when I can and post them here.

Craig - MC7 Oregon

[edvanland]

Craig:
Thanks for the info, would like to see the picks.  Where are you in Oregon?  My daughter lives in Portland area and I want to go see her when I sell my house and go full timming because then I will be retired.
Thanks
ED

[RJ]

Ed -  Let me ask you several questions, just to help clarify and assist with some intelligent answers:

1.  Are you downshifting the Allison manually when you're climbing hills, or letting it do it automatically?

2.  Are you keeping the rpm in the 1700 - 1900 range on a partial throttle when climbing?

3.  Are you downshifting when you begin to see black smoke out the exhaust?

4.  Are you tempted, with the power of the 8V92, to climb grades right alongside the four-wheelers and outrun the trucks?

5.  Have you bled the cooling system, including the dash defroster circuit, to make sure all the air's out of the system?

6.  Have you replaced all the weatherstripping around the radiators, radiator doors, blower compartment door, and engine compartment doors?

7.  I noticed that you've cleaned the squirrel cages, but have you also installed the larger units that MCI used when the 8V92 was ordered OEM?

8.  Have you looked under the coach and followed the transmission's cooling lines to see where they go?

9.  Have you weighed your coach, not only to see how much weight you're hauling around, but to also set your tire pressures correctly?

10. Do you have one of those dangly things or a mudflap across the back bumper to help keep oil & rocks off the toad?

11.  Are these enough questions for now?? 

FWIW&HTH. . .

[Burgermeister]

Have to be careful going to more "radiator".  In some cases, if you increase the flow capacity too much, you can slow the speed of the coolant down to the point it may actually REDUCE cooling performance, even though you have bigger radiators. 

Onward and Upward.

[edvanland]

Thanks Russ
Yes to questions 1, 2, 3, 6, &10.  NO to questions 5, 7, 8, 9.  WOW to question 10.  No to check on the no questions.
Thanks for the info.

Burgermister
Thanks for your input also, I have wondered about the capacity the water pump would be able to handle.
ED
MCI 7

[ol713]

My MCI 7 with 8V92 and 740 auto still has a heating problem on long climbs in Arizona, or any mountains.  So far I have had new thicker radiators with baffles put in, I did that what a pain, smaller fan pulley, squirlle cages taken out and cleaned, new 170 degree thermastats, new hoses, new seals around the squirrle cages, scoops at the rear of the side intakes, and also a mister system put on. I also put in a 5 gal puke tank to recover the water.  I also run with the rear doors open on long climbs, which helps a lot to let the hot air out. I haven't  found how the trans is cooled, don't know what I am looking for.  Wondering also about a different trans cooler set up.
Was thinking if there is a way to put two more radiators below the two existing radiators.  I have the lower louvers on each side door and a lot of room.  Was thinking of making brackets so the radiators could be swung out to get to the engine.  Course would have to put in electric fans on them also.
Any thoughts on if fessiable and how to plumb them and would it work?
Thanks
ED
MCI 7

Hi Ed;
       Talked with a charter owner here in the dsesert.  He suggested (as he did) that you cut the deck
       back under the squirrel cage approx 2".  This opens up th airflow area a little and he has had no
       cooling problems since. You cut the deck approx 2" forward to open the hole.  I have not yet done
       this to my MC-7,  but plan to.   Good Luck,     

[Buffalo SpaceShip]

Ed, your tranny might be the culprit, since you mentioned the long climbs. I don't know if you've seen Brian Diehl's thread about how he created a lock-up solenoid switch for his Allison: http://www.busconversions.com/bbs/index.php?topic=883 Getting lockup on a climb would prevent a lot of heat on the tranny oil from hitting your engine cooling system.

Also, you can consider adding an aftermarket air cooler for the tranny oil. Hayden makes many models to choose from. My V730 uses only a large air-to-oil cooler (a massive one made by made by American Industrial Heat Transfer) and doesn't dump any of its heat into the coach cooling system.

HTH & FWIW,
Brian Brown

[Barn Owl]

Have to be careful going to more "radiator".  In some cases, if you increase the flow capacity too much, you can slow the speed of the coolant down to the point it may actually REDUCE cooling performance, even though you have bigger radiators. 

The coolant flow through the motor should be the same regardless of your radiator size; Nevertheless, I think I know what you were trying to say, but when it comes to radiator cooling, I can not think that there would be a situation where you can have too much. When the coolant slows down in a big radiator it just has more time to cool.  Which is a good thing right?

[Burgermeister]

Barnowl,

No, No, No,

Agreed, more radiator is better, especially in marginal situations.   MCI never designed a cooling system exactly according to DD specifications.  They only designed for about 1/2 the parameter (one aspect) called for in DD specs.  They also selected a lower max ambient temp than DD specified.  However,

Too much of a "good thing" will get you back in trouble!!!

If you slow down the coolant too much, i.e.,  lots more radiator with same coolant pump capacity,  you lose the turbulence effect that fast running coolant in the tube causes.  It  keeps the coolant "mixing" so hot coolant is continuously exposed to the radiator tube and it gives up its heat to the air.

The technical term when it slows is the coolant "stratifies" meaning is layers, with the cool fluid forming a tunnel for the hot coolant running through and not giving off as much heat as it could.

Marc Bourget

[Barn Owl]

You can't beat an education, this is the neat thing about this board, one can learn a thing or two. I'm going to drop this on some fleet mechanics at work and see what experiences they have had with it. I intentionally didn't take thermodynamics in collage so I was not exposed to that concept. With the different densities involved, I could see where this could be possible.

Thanks

[Burgermeister]

An education?  Ya wants and education??   Well, I'll show you an education !!!   (LOL!)

Thanks for the interest.  If you really want to impress those fleet mechanics,  spend some time perusing the following site!

I've only looked at the "14 Rules" but it it's any indication, I'm sure you'll surprise some of those mechanics (unless they're excellent, in which case, I commend them!).


http://www.arrowheadradiator.com/technical_articles.htm

Marc Bourget

[ceieio]

Ed - here are three shots of the third radiator.  It lives below the right side radiator back of the side engine hatch.  The engine hatches have R & M updates with vent holes.  Their is a chunck of mudflap that ducts air to the radiator.  There is a picture of the door open and also one of it shut so you can see how it works.  The other shot is through the back door and you can see the radiator with shroud and the back of the wheel well on the right side.

It does take a couple of degrees off on a climb (more on a shallow climb) but I think it could be better with better ducting and a better fan.  I also think venting the rear engine doors near the blower outlets in the engine bay would make sense... the heat would leave the engine bay much sooner.

Craig - MC7 Oregon

[busnut104]

You already have a third radiator if you have not removed you bus heat. I use my large bus heat radiator for extra cooling. In the summer I can turn the heater on and I made it so I can exzaust the bus heat to the out side. In the winter I return the heat to the inside. 

[JackConrad]

Craig,
    That looks like the transmission cooler I installed in our MC-8 (same location). We re-routed the transmission cooler hoses so the transmission fluid goes to the this cooler first, through the OEM cooler, and then returns to the transmission. Since doing this, all temperatures (water, oil, and transmission fluid) run about 10-15 degrees cooler. And that is without turning on the fan. We have not been in any mountains yet see give it a real test.
    Do you pull outside air in, or push inside air out with the fan?  Jack