Transmisson cooler advice..... Jack Conrad are you there???

[RickB]

Hi all,

Spent the day today with Brian Diehl. What a great bus he and Hilary have. I drooled all over his ICM. What a great repower!!! He's also a great guy to just hang out with as well.

We took my bus for a ride and Brian shared some ideas on how to cure our overheating issues at 10k plus altitudes. One of his suggestions that I hope to work on before Spring is a transmisson cooler. He mentioned that Jack Conrad had fabricated one and I am hoping to get some info from Jack or someone else who has already fabricated one.
The encouraging thing is Brian drove my 8V71 ALOT harder than I do and the old girl really seemed to like it. Maybe one day I will live up to my motto and actually drive my Detroit hard. Brian, I am working on it

FWIW, the bus ran great and Lea and the kids and I were about ready to point her south and have an adventure, of course then reality stepped in and we remembered we have jobs. Which is a good thing in this economy.


Here's to Summer and 35 mph tailwinds....

Rick

[JackConrad]

Rick,
   We are prsently at a Bluegrass Festival, but when I get home tomorrow, I will post the info along with a couple photos.  Jack

[RickB]

 Jack, just a reminder to send the tranny cooler info when you get a chance. Thanks, my friend...

Rick

[TomC]

I installed an auxiliary trans cooler with thermostatically controlled fan (can turn it on continuous also).  I plumbed it so the hot oil comes out of the trans, through the auxiliary cooler then to the stock shell cooler.  This takes a big amount of heat out of the transmission before hitting the engine cooled cooler, hence keeping the engine cooler.  Installing yours in the right engine access door is one way to do it.  An although this sounds reverse, install it so the fan pushes the air from the engine compartment outward since the big engine fans create alot of pressure inside the engine compartment preventing the auxiliary transcooler to pull air from the outside in.  With this method, it will keep the transmission warm on cold days also.  Good Luck, TomC

[JackConrad]

Jack, just a reminder to send the tranny cooler info when you get a chance. Thanks, my friend...
Rick

Thanks for the reminder. The cooler is a Hayden brand and is 19" wide by 24" tall. The oil enters at the top of the cooler(from the transmission), exits at the bottom, then goes to the OEM oil to water cooler on the side of the 8V71 engine. From the OEM cooler it returns to the transmission. As was mentioned, this cools the oil before it gets to the OEM cooler. If the oil is cooler than the water (such as at iniatal start-up) this helps bring to oil to operating temps as well as removing heat from the water.
    Our fan is not on a thermostat, but has a switch on the side panel next to the driver. So far we have not even needed to turn on the fan. The squirrel cage fans on our MC-8 push enough ait into the engine compartment which, combined with the negative pressure area on the outside of the door the cooler is installed in, all our temps (oil, trasnmission and water) run 5-10 degrees cooler. Fan is only turned on during extreme conditions such as long grades or excessive ambient temperatures.  Jack

[John316]

Jack,

That is one perfect looking bus!!! Thanks for the pics.

God bless,

John

[RickB]

Wow!!! Jack that looks like it was fabricated at MCI. Awesome work. A couple questions. Do you happen to remember the model # on the Hayden cooler?
Also, what size inlet/outlet couplings are you using? The reason I ask is the cooler that they recommended on one site said that they recommended you use 1" inlet/outlet I.D. for the heavy duty Allison's. The one they recommended removed in the neighborhood of 80,000 btu's.  Yours looks like a standard smaller size and if it works great then I would rather use it as they are way less expensive.

I am ordering new seals for the upper rear access door and the seals around the squirrel cage fans as well and I am going with the smaller pulley as well. I don't want to be afraid of mountains anymore. It's funny because when we climbed Monteagle pass (outside of Chattanooga TN) my old girl never broke a sweat but the moment we attempted the Rockies she was at 200 degrees at the top of the first pass. We turned around and left the bus at the base of the mountain. Not a happy day...

I imagine that the fan was available 12 volt only correct?

Once again, impressive work my friend....

Rick

[JackConrad]

Rick,
   Thanks for the compliment.  I don't remember the model number (I bought it on Ebay). It is a singlar row of tubes in the cooler, they also make a cooler with 2 rows of tubes (same width & height, but twice as thick).
     Inlet and outlet are hard to get at, but it looks like thay are 7/8" or 1".  Fan is 12 volt.  All wiring on our bus has been replaced and the only thing that is still 24 volt is the engine (starter, engine stop, fast idle and emergency stop solenoids) and defroster fans.

[TomC]

Jack- looks great, but may I make a suggestion?  And this comes straight from Hayden.  When the cooler is installed with the tubes going vertically (like yours), they highly recommend you plumb it so the oil comes in at the bottom and exits at the top.  This is to prevent and air pockets from forming causing a decrease in oil flow.  On my cooler, my tubes are horizontal, so it didn't make a difference which way it is plumbed.  But from what I have read, please consider switching your lines.  Good Luck, TomC

[JackConrad]

Jack- looks great, but may I make a suggestion?  And this comes straight from Hayden.  When the cooler is installed with the tubes going vertically (like yours), they highly recommend you plumb it so the oil comes in at the bottom and exits at the top.  This is to prevent and air pockets from forming causing a decrease in oil flow.  On my cooler, my tubes are horizontal, so it didn't make a difference which way it is plumbed.  But from what I have read, please consider switching your lines.  Good Luck, TomC

Tom,
   Thanks for the advice.  Since we are changing engines next month, sounds like a good time to do this.  Jack

[rusty]

Rick, Good Luck with you project. If it is not to for out of you way stop by on your way south.

Wayne

[RickB]

Alright Jack.... out with it. What Motor are you switching to??? No secrets between friends.

Great so now I'll have another busnut out there to have horsepower envy over!!!

I have decided to go without the fan and just use the cooler. My thinking is I can always add it later and from the sound of Jack's post he rarely uses it.

Where can I get the transmission lines and how much are they gonna be roughly??

Luke at US coach made a good point that I should change the air filter as well since I don't know how many miles it has on it and any restriction from there will affect temp and overall horsepower.

Thanks for your help guys...

Rick

[John316]

He had a good point about the air filter. Ours was loaded with stuff. We even found a nest of some sort in there .

God bless,

John

[JackConrad]

Rick,
    When we installed the transmission cooler, we all new transmission hoses made by a locel truck place that makes custom hydraulic hoses. Since they are rated for 3000 PSI and our 740 does not exceed 200 PSI (per the manual), we should never have a problem. 

John,
    You have no worries, we are just replacing our tired 8V71 with a much fresher 8V71 (only a little HP increase). As near as we can tell our 8V71 was last rebuilt by Greyhound and therefore was probably set up at about 277-280 HP. The one we are installing is set up at 318 and has Jakes on it.  Jack

[NJT5047]

I'm wondering what the underlying problem may be for your heating problem.  An 8V71N with an automatic shouldn't overheat.   Assuming the engine isn't allowed to drop below proximal to 1800 when climbing hills.  Keep it on the pipe when climbing hills.  Any time the engine won't accelerate when climbing a hill, select the next lowest gear.   An automatic won't do that unless you floor the accelerator.  Don't be shy about forcing a shift.  Keep the RPMs in the upper ranges..or against the gov when climbing long hills.   Free and easy is the trick.  Lugging a 2 stroke will destroy your wallet.
If the transmission is causing your heating problem, that's an indication of an impending failure.  The combo you're running should easily cool..if you have good radiators and seals.   
On an MC9, if you have any rotted weatherstrip around the radiators or encloser doors, you'll have overheat problems.   If blower belt tensioner is not functioning correctly, same. 
If there's any rust-thru or air leaks between the radiators and any areas outside the radiators, it'll overheat.   Anything that allows air to 'leak' around the radiators before going thru the squirrel cage blowers equals a problem. 
All the usual heating problems could cause issues...thermostats, water pump, engine head gaskets leaking...and the list goes on. 
You have (should?) a transmission cooler mounted on the streetside engine.  And there's a water to engine oil cooler on the same side of the engine.  Follow the big hoses from the transmission and they should lead to an oil cooler.  If no trans/water cooler (unlikely), the transmisison may be getting hot, but it isn't causing your engine heating problem.   
An MC9 has larger radiators and inlets than earlier models.  If you find your rads are crap, you could  install 8V92T rads.  That's as good as it gets.
You shouldn't have heating problems if you have good, clean standard radiators.  Most MC9s have 6V92TAs, which will make more heat than an 8V71N.   
Air leaks in the radiator/squirrel cage compartment are often the cause of heating on MC9s...and often overlooked. 

JR
BTW, Jack, what engine are you going back with?  An 8V92TA?