OBA and A/C...can it be done???

jpdeuce

Basic User
City
Houston
State
TX
#1
So I am trying to get my Scrambler eventually to be a daily driver...however...being in Texas and having to wear decently nice clothes to work, I will definitely need a/c. But...I don't want to sacrifice the OBA option...so I was wondering what the deal was with these 2 items.

Is it impossible to have both? Can they run off the same compressor? Do you sacrifice engine power for running these? I've got a 4.2L 258 in there...and would like to keep it that way.

Anyway...what's your thoughts? I'm sure it isn't impossible...just wanted to see what was involved. I'm guessing there's OBA compressors you can run electricity off the rig for...but where to put them would be fun. OK...I'll let you guys talk now...
 

dirtyjeep

I like it dirty.
City
Arlington
State
TX
#2
You can run a York in addition to your AC compressor or you can go the electric compressor route. A York would be much more efficient though.
Robbie on Cowtownjeeps has both on his TJ.
You'd have to fab brackets for it.
I've been considering it on my Scrambler but I need to get my AC working first.
 

jpdeuce

Basic User
City
Houston
State
TX
#3
Well I've got a York sitting in my garage (the big one...10 cu inch one or whatever) that I was going to use on the a/c or OBA...so are you suggesting I run 2 compressors off the engine? So I should get a basic compressor for the a/c and use the York for OBA? Or I should use the York for what is more important and get another compressor for the other function?

Also, does running 2 compressors off the engine take from the power and efficiency of the engine? Being a daily driver (hopefully) this is something I am concerned with.

I'm kind of leaning toward the choice of the electric compressor...that way I can leave it off when I am not using it (90% of the time) but have the option. Plus I can have a cool switch mounted somewhere ;)
 

dirtyjeep

I like it dirty.
City
Arlington
State
TX
#4
Yes, there will be some draw with running two compressors but they use a clutch and are only engaged when the compressor is turned on.
I do recommend talking to Robbie. He installed his.
The York is more efficient than a stock AC compressor and much more efficient than an electric one.
I still haven't decided if I'm going to hook up the AC or not on mine. If I do I'm going to add a York for the OBA duties.
 

jpdeuce

Basic User
City
Houston
State
TX
#6
Nice...appreciate it. Nice to see Longhorns sticking together :cool:

So...on a related note...what's the disadvantages of running an electric compressor instead of engine run compressor? What are the ADvantages?
 
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Zodiac

CJ-8 Member
CJ-8.com Member
City
Macomb
State
MO
#7
Disadvantages to electric- noisier, takes longer to build pressure, current draw, and more "stuff" to have to find a place for.
Advantages- don't have to have the engine running to charge the tank, no more adding a teaspoon of compressor oil once every hour of use, can be mounted anywhere (or not mounted at all, as evidenced by Hayduke, who keeps his bolted into the bottom of a toolbox with the air and power plumbed out the side).
Advantages to belt-driven- always at hand at the flick of a switch, doesn't take up much room, quieter than electric, FAST pressure build, negligible resource draw (slight engine drag).
Disadvantages to belt-driven- takes up room under the hood, under-hood plumbing, can't be relocated, parts availability, and that oil-adding thing.
Advantages to PowerAir or other CO2 type tanks- Completely portable, can get lots of fills/air time on one tank.
Disadvantages to CO2- takes up cargo space, risk of explosion (loose tank may get punctured), having to get the tank retested and refilled.
HTH,
 

jpdeuce

Basic User
City
Houston
State
TX
#8
Great list Zodiac...awesome

I think after that list I am leaning electric and use my York for the a/c...keeping into consideration how much I would actually use the OBA. I'm sure people will say that I will use it more than I think I will...but who knows.

Once the electric compressors are charged up do you get the same type of pressure and usage out of it? Having to wait a couple minutes for the same usage wouldn't be a deal killer for me I don't think. And it's only loud when you have it on...meaning when you need it...and you don't need it all the time...so that doesn't seem like a deal killer either.

I think being able to locate it on the rig anywhere I want and not having much maintenance on it are key factors for me.

Thanks fellas
 

Zodiac

CJ-8 Member
CJ-8.com Member
City
Macomb
State
MO
#9
Pressure is pressure- once it's in the tank, it doesn't matter that 5 gallons at 120PSI was put there by a belt driven, electric, CO2 charged, or any other kind of compressor. All other things being equal, the biggest differences between the electric and the York are charge time and noise. If you don't care about either issue, then either method will work equally well for you.
EDIT: One other thing to bear in mind is HEAT- compressor heads can make a great deal of heat. I thought of this just as I hit the "Submit Post" button- what if he's got a LOT of air-tool work to do, or is refilling his 39" Boggers?
On a York, the heat issue is partially allayed by the fact that the head is large, in a well-ventilated area (behind the engine fan), and there is lubricating oil circulating in the air passages. On the electric compressors, there are none of these, and they can get REALLY hot. I don't know if they can actually seize if you use them too much, but it's something to consider.
If you do find you are using a lot more compressed air than you had originally anticipated and it's hitting the compressor pretty often, you could always increase the volume of your storage tank. That way, the compressor only turns on once in a while... the flipside to this is that, when the tank drains down, the compressor will be on for a LONGER time, so I don't know that there's any way to get away from it. I suppose you could gang several electric compressors together so you have more of them each doing less work than only one would, but there you're back to the "how much space does all this stuff take" issue. /EDIT
 
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jpdeuce

Basic User
City
Houston
State
TX
#10
Gotcha...all great points. Firstly I won't ever have 39" boggers...but I guess the possibility is there that I might have to fill them up...never know...but I would hope the guy with 39" boggers thought of that and thought about supplying his own air at some point...but who knows.

Secondly, I was thinking...I thinkI have seen some people build air tanks into their roll bars...is this possible? If an air tank is filled up does it hold pressure until you use it or it is released? Cause you could just ride around with air ready to go in the roll bars and not have to completely charge it up everytime...not sure...I'm guessing there's always a slow leak that would happen...or maybe it isn't good to keep air in the tank for that long?

I just don't think I will be using it that much...but again...you never know. Besides air up at the end of the trail...what are the most common uses for OBA?
 
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