Aux trans cooler

[edvanland]

Here is the plan. I am going to install another trans cooler, oil to water, on my MCI7. The new cooler will be in line with the old one. The new trans cooler will have its own radiator, fan, & pump. It will not be part of the bus cooling system. I talked to Luke and he thought it would work. The young man who is doing the work and came up with the idea of a seperate radiator is quite inventive in his ideas and his workmanship is top notch. Will get this going as I now have the cooler, radiator, pump, just need to get the right size fan. This will be mounted on a swing out system on the left rear side of the bus. The fluid will go through the new cooler first and then the original so if something happens to the aux system the original system will still cool the fluid. I am hoping to drop the overall temp of the bus cooling system by 5 to 10 degrees, course more would be nice. I live in centeral Arizona so no mater which way I go I have a long grade to climb, and as you may have heard it does get hot in Arizona.
ED MCI 7

[luvrbus]

That setup is fine in the summer but how are you going to heat the transmission in the winter a cold running 740 will fail more than one running at 200+ degrees

[edvanland]

Good thought. I will talk to the installer and have him put a switch to turn off the pump and fan.

[buswarrior]

Quite a few busnuts have installed an oil to air cooler inline ahead of the stock cooler in order to dump the heat out before the engine cooling system, with a thermostatically controlled fan. Running through the stock cooler on the way back will add any heat needed when operating in cold conditions.

Mounted to the curb, side engine door.

Here's one source:

http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=2&Category_Code=Allisoncooler

There is more than one way to skin a cat, or build a coach.

Do it your way!

happy coaching!
buswarrior

[luvrbus]

Me I would spend the money and go with a air to air turbo cooler cools the 8v92 down ,the way those engines are designed is water goes through cooler first for cooling of the engine and transmission oils

Get the cooling system up to par there is no need for anything but MCI owners do face a challenge pushing water up through the small radiators

[HB of CJ]

And...if you want the inline system to help WARM the tranny in the winter and are prepared to accept the efficiency hit during very hot weather, then your inline approach will work fine....but it kinda defeats the purpose of the auxillary trans cooler in the first place.

If you dedicate the cooler just for the tranny, you can then more easily address the challenges of 4 season driving by adding the fore mentioned fan switch to cut it out of the works in the winter.  Summer and fall driving will probably be systems neutral, but you may need the fan in the summer.

Taking the tranny cooling problems out of the loop of engine cooling may help you keep your mill temps cooler in the summer; especially when driving hard in extremely hot weather.  Why compromise things with your in line approach and the possibility of having it  not work so well?  HB of CJ (old coot)

[TomC]

All that extra equipment is not necessary-meaning the extra coolant and extra water pump. I used the DB-341DC-12 auxiliary oil to air cooler with thermostat from http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=2&Category_Code=highflowcoolers-fans. I installed it on the side with the fan blowing from inside to outside. This sounds in reverse, but with the big fan creating a lot of pressure inside the engine compartment, it is better to have it blow from inside out-besides the hot air is still cooler then the hot trans fluid. I have it plumbed in line between the hot outlet and the original cooler to take some of the stress off of the radiator. I also installed an on-off-on switch to select thermostat-off-continuous on if I wanted. Highly recommend you go with this instead. No coolant, no additional pump and it is designed for the high flow that an Allison needs-i.e. 1" fittings.  Good Luck, TomC

[TomC]

Try this http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=2&Category_Code=highflowcoolers-fans