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Author Topic: MCI 7 extra radiators  (Read 3526 times)
edvanland
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« on: August 03, 2006, 01:49:11 PM »

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
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Ed Van
MCI 7
Cornville, AZ
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« Reply #1 on: August 03, 2006, 02:11:38 PM »

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
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Craig MC7 - Oregon USA
edvanland
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« Reply #2 on: August 03, 2006, 03:00:35 PM »

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
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Ed Van
MCI 7
Cornville, AZ
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« Reply #3 on: August 03, 2006, 03:25:11 PM »

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??  Grin

FWIW&HTH. . .
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RJ Long
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« Reply #4 on: August 03, 2006, 11:32:05 PM »

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.
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edvanland
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« Reply #5 on: August 04, 2006, 10:21:11 AM »

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
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Ed Van
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« Reply #6 on: August 04, 2006, 08:17:10 PM »

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,     
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Buffalo SpaceShip
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« Reply #7 on: August 04, 2006, 10:36:52 PM »

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
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Brian Brown
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« Reply #8 on: August 04, 2006, 11:37:46 PM »

Quote
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? Wink
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L. Christley - W3EYE Amateur Extra
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Have fun, be great, that way you have Great Fun!
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« Reply #9 on: August 05, 2006, 04:08:40 AM »

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
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Barn Owl
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« Reply #10 on: August 05, 2006, 07:27:19 AM »

You canít beat an education, this is the neat thing about this board, one can learn a thing or two. Iím going to drop this on some fleet mechanics at work and see what experiences they have had with it. I intentionally didnít 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
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L. Christley - W3EYE Amateur Extra
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Have fun, be great, that way you have Great Fun!
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« Reply #11 on: August 05, 2006, 11:04:45 AM »

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
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ceieio
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« Reply #12 on: August 05, 2006, 10:58:28 PM »

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

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Craig MC7 - Oregon USA
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« Reply #13 on: August 06, 2006, 04:56:31 AM »

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. 
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JackConrad
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« Reply #14 on: August 06, 2006, 05:22:00 AM »

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
« Last Edit: August 06, 2006, 05:25:36 AM by JackConrad » Logged

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« Reply #15 on: August 06, 2006, 08:32:39 AM »

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. 

I too have used the coach heat on occasion to take some heat off of the engine. But how did you route the heat away from the interior for summertime use?

Thanks!
Brian
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Brian Brown
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« Reply #16 on: August 06, 2006, 12:33:00 PM »

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

Jack - It pulls outside air into the engine bay.  I get to test it all the time as I have a first gear pull to get to my house Smiley  (I can take it at second if I make more of a run at it).  At slow speeds it seems to work OK too. Pulling the hill out of Las Vegas in mild temps (80's) it really helped too.

I wonder about exhusting the air (rather the little fan working against air pressure to draw in and exhaust air) when the load is high.    Pulling the hills in Northern California and Southern Oregon it helps as well.  These are steep and long, with my bus in 2nd gear most of the time, RPM's up so lots of air coming through the blowers.  I can still see an impact on the dash gage when I switch on the fan under these conditions, so it must work OK.  When I get current projects done, I will start thinking about better ducting to see if I can get more benefit.

I think I would like to come up with some louvers or vents that can be opened or closed near the top of the engine doors to exhaust the blower heat directly out of the back of the bus without passing it through the engine bay.  Seems like it would help in hot weather.  I would like to be able to close these in cooler weather to keep the temps in the warmer range.  Not sure if it will have any effect if I do it.  Opinions anyone?

Craig - MC7 Oregon
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Craig MC7 - Oregon USA
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« Reply #17 on: August 06, 2006, 01:13:53 PM »

Ed,

You said you went to new thicker radiators and a smaller pulley. Was this an upgrade to 8V92 sized radiators or something more?  If you were upgrading from a 8V71 or 6V92 system,  did you go to the larger squirrel cage fans?
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RJ
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« Reply #18 on: August 06, 2006, 02:46:13 PM »

Marc -  In Ed's response to my list of questions, he answered "NO" to the one about the larger squirrel cage fans.

Obviously, these move more air, so are worth the investment.

Ed -  Get rid of that mudflap hanging off the back bumper - NOW!  Those things trap hot air UNDER the coach, not allowing it to escape.

GMC hung a full-width stiff mudflap across the coach immediately behind the back axle to create a low-pressure area under the powertrain, thereby helping to draw the hot air out of the engine compartment. 

These are a little more of a challenge to fabricate on a T-drive coach, but it would be worth the $$ - which I'm sure would be a lot less than adding another radiator and associated plumbing, etc.

HTH. . .
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RJ Long
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edvanland
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« Reply #19 on: August 06, 2006, 03:24:35 PM »

Meny thanks to all who have responded.  I now know a lot more of what to look for and what to do.  I think the first thing is to figure out the trans cooling better.  I will also take the bus to a Allison Trans man in Phoenix, who did a rebuild on a friend's GMC.  Will let you know latter what I have done and how it works thanks to all your efforts and ideas.
ED
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Ed Van
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« Reply #20 on: August 06, 2006, 07:58:10 PM »

In the comp. where the heater radiator and fans are located there on both sides fiberglass chutes that deliver the air to the inside of the coach. I made for each side a metal shoot which I can close off the air from going inside and directs to the outside with a metal slide, When I want heat in the coach I have a end cap that I install. YOu would not believe how much hot air with a lot of force comes out of the shoots. If you would like I may be able to post some pictures.
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