GMC Drivers Air

[FloridaCliff]

For continuity I am starting a new topic with this

Russ wrote:

If you're going to tear out the old defroster unit while poking around with the door closer mechanism, here's a tip:

The 4905s had an HVAC unit in the same location.  That's right - not only the defroster heater core, but an A/C evaporator core, too.

You might consider finding a used one, changing the blower motors to 12V, and installing that.  Run some freon lines to the rear (use the existing ones in the tunnel), hang a small condenser on the outside of the radiator and a Sanyo compressor off the old A/C drive, and bingo!  You've got driver's A/C!!

FWIW & HTH. . .

Russ,

You wouldn't happen to have a picture of this?

Cliff
 

[DrivingMissLazy]

For continuity I am starting a new topic with this
I had one on my Eagle 10. Compressor running off the drive for the fan.
I had overheating problems when I went to bigger engine and had to remove the condenser coil from the radiator.
Later saw an Eagle with the same setup with the condenser coil mounted in the front of the spare tire compartment with the fans on it blowing forward. The guy said it worked great. Sure would have been nice to have had.
Richard


Russ wrote:

If you're going to tear out the old defroster unit while poking around with the door closer mechanism, here's a tip:

The 4905s had an HVAC unit in the same location.  That's right - not only the defroster heater core, but an A/C evaporator core, too.

You might consider finding a used one, changing the blower motors to 12V, and installing that.  Run some freon lines to the rear (use the existing ones in the tunnel), hang a small condenser on the outside of the radiator and a Sanyo compressor off the old A/C drive, and bingo!  You've got driver's A/C!!

FWIW & HTH. . .

Russ,

You wouldn't happen to have a picture of this?

Cliff
 

[Runcutter]

This would be great for our 4107, too.  Although we have all the bus air components, the previous owner didn't keep it up (although, he did tell us that it should work if we added freon).  The compressor driveshaft is disconnected to avoid parasitic drag.

Without road air, our option is to run the auxilliary generator, and the rooftops (there's no inverter and I'm not sure I'll add one at this time).  I don't know how well the rooftops will cool the big greenhouse where I sit.  (Of course, the other option is for me to lose weight one ounce at a time, but my urologist doesn't like that alternative). 

So, would this suggestion work on the 4107 for air up front; would we be better with the generator/roof air (with the generator cooled through the bus radiator, I'm not sure if the added thermal load could be an issue); or should we get the road air serviced ($$$?).

We're tentatively planning a 5000 mile trip in late July, early August - leaving Dallas to work with a  client in upstate New York, another Mother-in-Law to New Brunswick trip, then return to Dallas.  Although New Brunswick is nice that time of year, it does tend to get warm in the southern states - particularly on the westbound return trip heading into the sun.

Thanks for the ideas.

Arthur     

[RJ]

Cliff -

I've seen this done two different ways:

First one used the OEM PTO for the A/C off the LF of the engine, just fabricated some brackets and belt drove the compressor.

Second one used a PTO on a V-730, again with some fabricated brackets and a belt drive.

Sorry, no pics as I didn't have a camera along with me at the time.


Arthur -

Yes, this should also work for the 4107, as the underdash area is basically the same as the 4905s.  You can utilize a lot of the existing OEM stuff, just re-routed. 

Does your 4107 have the big Carrier compressor behind the LR wheel, or is yours one that uses the dual A7 GMCs?

FWIW & HTH. . .

[TomC]

First off, would highly recommend you separate the generator and big engine cooling.  Especially in summer, you're going to need all the cooling you can get.  I have a separate remote radiator for my gen that uses a squirrel cage blower with a 1/2hp 2-speed belt drive motor, high for during the day, low after dark for quiet operation. Works well and don't have worry about heating up the big engine.

I have three roof airs with the front one close enough to be able to blow right on me.  With the addition of a dash fan blowing right in my face, I stay nice and cool-even into the sun.  Two roof airs keep the bus cool up to 100 degrees, then can kick on the third one.  Good Luck, TomC

[Runcutter]

Russ, the bus air is original equipment - I'll have to look to see if it's a Carrier or Trane compressor. 

Tom, I agree on separating the systems.  Right now, as I look at many of the mechanicals, it's a "what were they thinking?"  The Kohler generator and the 8V71 cooling systems are tied together, and they both loop through the water heater.  On the way home last summer, if we ran the generator while parked in the evening, it'd shut down after about an hour - I suspect high temperature sensor.  Without the 8V71, there's no air through the radiator.  It is, at least (or at $2000) a brand new radiator, so that's one advantage.  Along the lines of "what were they thinking," one of the family members of the previous owner was an electrical engineer.  We have so many subpanels and doodads that the manual has over one page devoted to how to set the integral alarm clock, which is also a thermometer (both inside and outside).  The refrigerator can tell the generator to start up if it's warm, but a heater near the water tanks can tell it to start if it's cold ... you get the picture.

If we don't do anything with the road air, I'm wondering about putting a radiator/electric fan in the A/C evaporator compartment, solely for the Kohler.  On the other hand, some of these expenses can make fixing the road air an attractive option.

With business travel, and health issues for the last 6-7 months, I haven't been able to do much work on the coach - and so far we're working on the interior.  The last time I started the engine was in February to move from one space to another, a couple of weeks after hernia surgery (somehow, that did help me notice the strong clutch and lack of power steering, but it couldn't be helped).

She's at an RV storage lot, about 4 miles from the house, so it's tough to do much serious mechanical work.  It looks like we're about to be awarded a significant contract, so that'll generate the money for power steering and new tires, as well as a full PM; clutch adjustment, and throttle cable lube.  At the APTA conference a couple of weeks ago, I was talking with ABC Bus - one of their shops is in Grand Prairie TX, about 20 miles from us.  I've also considered Tejas Coach Works in Mineral Wells, about 50-60 miles, but there seems to be no way for me to get home after dropping off the coach - the city isn't even on the Greyhound network. 

The size of the contract (and another potential one that's out there) may also let me think about how best to get on-road AC.  I've considered running the generator, but as Tom says, I'm concerned about adding heat.  On the way home last August/September, she ran right around 180 (without the generator running).  The temperature in the driver's seat wasn't 180, but it wasn't a balmy 72, either.  It might have been better if the windshield fan had worked, but it was frozen.  I've ordered a new driver's fan motor and other stuff from Luke, but for some reason they won't send me anything.... either the order is too small, or I'm on "ignore".  I really, really paid them for the stuff I picked up there in the middle of March, so I don't know what is going on.  Does anyone have another source for driver's fan motors -  without one, I'm really cooked...  in more ways than one.   

There is no inverter, I'd rather not go to the expense of an inverter/battery/ setup (probably need full sine wave), just to run the rooftops until we really know how we're going to use the coach.  The last trip, and the next probable one, are drive all day, sleep at truckstop/Walmart/campground, drive all day, sleep, and repeat until reaching relatives, home, or whatever.

My learning process continues.

Arthur

     

[TomC]

Arthur- until you do separate the gen from the big motor, so you can run the gen when stopped without tripping the overheat, get a couple of box fans and just hang them on the engine radiator grill blowing onto the radiator, and I'll bet that's enough to keep it cool. 
Those little dash fans are quite cheap at either a big truck parts house or like Camping World.  Keep us up on your progress.  Good Luck, TomC

[Runcutter]

Box fans, what a good idea ... I sure wouldn't have thought of that one, but it makes perfect sense. 

Thanks.

Arthur

[DrivingMissLazy]

Here is my opinion and actual experience which may differ from some of the other posts.

My 10 KW Wrico unit was plumbed thru the engine coolant system and I loved it. I did have to do a little modification since the former owner had never had the conversion on the road and only lived in it at his mobile home park.

The first problem was genset O/T shutdown while parked  in the desert with outside temps over 100 during the day. I installed two 16 inch radiator fans from Pep Boys on the outside surface of the radiator blowing in. I also installed a thermostat switch into the core of the radiator set for 190 degrees. A yellow indicator light on the dash indicated when the fans were operating. I later added a circulating pump in the genset coolant circuit to help move the water thru the long lines from the genset to the radiator and back since they were on opposite sides of the coach. I really never determined for sure if this was needed, but it did extend the time between fan operations while I was parked.

Typically they would run 10-15 minutes and then off for 30-45 minutes. They would also come on while climbing mountain passes and assisted greatly in keeping the main engine coolant down to 200 or less. So I was killing two birds with one stone. I had changed the 6V92 to an 8V92 so i did have some cooling problems, but the auxiliary fans more than compensated for the additional heat the little genset engine added  to the overall heat load. If the auxiliary fans did not provide enough additional cooling while climbing the mountain passes then the mister system I designed and installed solved the extra heat load problem. And no I never had a build up on my radiator from the mister system.

In general I really liked the system and it worked great. The Webasto was also tied into the same system and it was a great combination for heating the coach or for maintaining hot water for showers since I had three sources of heat, the main engine, the genset and the Webasto.

For those who always seem to be concerned about a few extra connections and the possibility of a leak somewhere I have to say that if you are going to be worried about little things like that then maybe you should just stay home. I travelled over 150,000 miles and never experienced a leak, or any other breakdown problem that prevented me from making it home.

Richard

[Runcutter]

Richard, that makes a lot of sense as well.  How did you deal with the minimal clearance between the radiator and the grill?  If I recall, you're talking about an Eagle.  One of my elements is trying to restore the 4107 to original outside appearance (or as close as I can get).

Arthur

[DrivingMissLazy]

The auxiliary automotive radiator fans are quite thin. About an inch or so if I recall properly. Whatever, there was no problem installing them between the radiator and the outside grilled door on an 80 Eagle 10. Be sure and get the thermostatic switch that is available for controlling them.
Richard

[H3Jim]

Did you ever have one of them burn out? 

Dick Wright is concerned with  mine that since it's a 12 volt, that it might not be reliable.  (zirgo)

[DrivingMissLazy]

I really do not understand Dick's concern. I ran mine at least 10-15 years and I spent a lot of time in the desert as well as on the road. Never any indication of any failure. A failure would have been readily apparent as you could witness the engine temperature gauge go down after they came on and also, the genset would have overheated if they failed while parked out at Glamis. Mine were also 12 volt designed for supplemental cooling on an automobile.
Richard

Did you ever have one of them burn out? 

Dick Wright is concerned with  mine that since it's a 12 volt, that it might not be reliable.  (zirgo)