Building my OBA

jeepcomj · Mar 22, 2008

I'm in the process of building an on board air system for it right now on my 86 comanche that i put a camaro 3800 motor into...will update with pics as it comes along.
so far spent (at menards)
$7 on a cheapo hose i can use offroad
$35 on a pretty heavy duty air filter/oiler/pressure regulator system.
$6 on the oil/water seperator
$5 on some fittings
it's meant to run : air tank/compressor, filter, regulator, oiler....with oiler being for the tools.
I'm running it : filter, oiler, air compressor (a/c compressor), regulator, oil/water seperator
doing it this way so that I can oil the compressor automatically once i've got the drip feed adjusted.
still need to get the hardline for between the oiler and intake of the compressor (has to be hardline cause suction will cause it to go flat otherwise), and output to regulator line. I've got all the connectors I will need.
for now, I will be running tankless. when I have the accessories in the bed all set up, I will plumb the truck for a tank.

jeepcomj · Mar 22, 2008

got everything I need except for the pressure cutoff switch, and one 1/4x1/4 threaded adapter.
here you can see how little room I have to work with

but, on the bright side it's still easy to work with

drilling out for 90 degree fitting

first holes

back of compressor

with manifold mounted

manifold. I have to weld plugs on the two open holes

here's the completed setup

air filter and oiler

regulator, oil/water seperator, connector. haven't installed the connector/seperator yet because i'm not sure where they will be located.

back of the compressor. as stated, i gotta weld the holes yet

the braided line is actually water line. copper inside, stainless steel braiding. $3 each at 20" long, and they are meant to hold up to 2,000 PSI. we'll see how they work

I do need to pick up a pressure cutoff switch before I can wire this all in. otherwise it's a pretty complete system

jeepcomj · Mar 22, 2008

had my bro weld the manifold up for me, and started mounting up everything on a sheet of diamondplate

jeepcomj · Mar 22, 2008

weeelll.
finished the unit today. turned out well...now i just have to tape all the threads and put it together permanently, then mount it all in my truck
it turned out pretty compact as well

i'll have to get an unloader valve at some point, and I'll throw a new pressure regulator in it soon as it arrives. tossed an old one on it for now...not even sure if it works.
but. i'm happy with it so far.

Frank Z · Mar 22, 2008

Lookin Good!!

5.2poweredxj · Mar 22, 2008

Where at menards do you find this stuff. Do you got names for the parts or numbers? I've been wanting to do oba setup on mine.

jeepcomj · Mar 22, 2008

the regulator/filter/oiler combo is in the hardware department next to the air compressors, same with the seperator and air connectors. all the lines and fittings are in the plumbing department, so are the clamps. any screws/nuts would be hardware, but i have those at home, the relief valve i got at reinemans because menards doesn't carry that. the pressure switch i had, but will replace it with one from TSC or from my dad's work at Rhibar trucking. the check valve was from a friend, the diamondplate i had, and the prefilter breather thingy i got at a junkyard.

wiring and fuses were from menards electrical.

and the project still hasn't broken $120 yet

5.2poweredxj · Apr 30, 2008

How that oiler setup working? What type of oil are you using?

I bought the same one just starting to install it all in my Zj. I got the tank mounted and the hose ran to the front. I got one coupler and gauge on the tank itself in the rear hatch. There another coupler and gauge that comes threw the grille. The dryer is mounted. But I got to make a trip get the rest of the fittings.

So far I spent
35 on the air filter/oiler setup
9 on the little pre filter filter
20 on fitting most I got for free
free tank that I had cut down
10 for 60 feet of 3/8 hose
free pressure switch
12 on the dryer

I take pics of mine so far tomorrow.

jeepcomj · Apr 30, 2008

I actually never finished it...I've been a bit busy working 80 hour weeks, but I actually just quit menards so I'll be able to finish it now.

gcurtis · Apr 30, 2008

If those are water lines you are using, I truly be concerned about burst pressure.

Lines coming out of the AC unit get VERY hot and I've seen 250 PSI air brake lines burst due to heat and pressure.

FordGuy · Apr 30, 2008

Looks really good, but as the other guy said, Water Line? Could you use some FC300 hose?

Frank Z · Apr 30, 2008

FWIW, I used refrigerant tubing on my system. It can handle the pressures delivered by the York compressor.

ert01 · Apr 30, 2008

The other thing to be aware of is that oil/air seperator will melt a bit and blow out. I used the same one for mine and it melted after the first outing since the air coming out of the compressor is so hot. You will want to find a nice beefy metal unit somewhere.

And try to find some way to keep the metal cans attached to the bottoms of the filter and oiler... if they rattle/vibrate they tend to spin themselves out of those ones and fall off on some remote trail somewhere. Mine were mounted under the hood and they fell apart on me. Now I make sure to zip tie or tape them in place.

5.2poweredxj · May 1, 2008

Here mine so far first the grille picture of the coupler and gauge. (Sorry it not a xj) ignore the relief valve just put it there to pressure the system using a shop compressor.

Second is the filter and oiler behind that is the dryier

Here my tank I made up and mount it in the rear. It 17" roughly between the ends and 10.5" wide. I figure it over 5 gallons.

WB9YZU · May 1, 2008

Something very simular I did to my YJ.
http://www.mcjag.org/projects/ronOBA/MyOnBoardAir.htm

As it says, not much capacity, but it does the job nicely.

Ron

p.s. I got mixed up on the OBA thread I was responding to, but this should be OK too :

YELLAHEEP · May 1, 2008

Yeah, those lines coming directly from the compressor need to be able to handle serious heat. My homebrew Sanden OBA started out using regular compressor hose which lasted 30 minutes. I upgraded to kevlar lined hose but the heat tore up the rubber and it burst.

I went to NAPA and had them make up some hydraulic pressure lines with brass spin connector fittings like what are used on tractors/backhoes/bobcats and they have worked very nicely.

I also think you'll need a better lubrication system. I tried a similar oiler and it didn't work. I've burned up 3 sanden units and now I simply squirt a bunch of motor oil into the intake on initial start up, and if it's gonna run for a while, I have to remember to add a squirt occasionally.

5.2poweredxj · May 3, 2008

Got mine on the motor tonight. The oiler can really over do it. I can get it to pump out the oil on the other side. I turn it down to about a drop an min roughly. It take about 1 min to fill the system to 115 from 0. Test filled a tire from about 12 psi up to 32 psi. Did it as fast as normal air compressor and maybe even alittle faster. The safty bleed opens at 120. I don't know what type a compressor is used on a V8 grand?

Will take pics of it all together under the hood tomorrow.

Building my OBA

jeepcomj

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jeepcomj

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jeepcomj

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jeepcomj

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Frank Z

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5.2poweredxj

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gcurtis

Shirley Temple was a nug.

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