On Board Air

[mriplaybass]

Like I need another project! But.........................
I have a 10 lb CO2 tank that I can use for air, but I have always liked the idea of having unlimited air for more than just tires. Converting an old AC compressor is what I would like to do sometime in the future. I know a lot of you have done this, so rather than just jumping in and starting blindly, I thought I would pick the collective brains of everyone here. Any ideas would be greatly appreciated.

 

[Torxhead]

As far as I know this is top of the line for what you seem to want:::Kilby Enterprises::
Issues with this type of system is heat from compressing air and lubrication of the pump. The York air compressor, I believe does have a lubrication system, plus it puts out a lot of air, and it is the heaviest and most expensive.
I developed my system and it works fairly well. It is a Sanden compressor, with a homemade lubrication system. It puts out about 3/4 of what the York does and cannot fill everybodys elses tires after a trail run without melting, I think anyway since it does get pretty hot. I did get a lot of help developing the system by looking at other Jeepers systems and going thru a Grainger catalog to see just how an air compressor is set up. Those 5 gal. air tanks are great to mount under the body in front of the gas tank if you have enough lift to clear it. I have seen guys get by with the larger electric pumps and do just fine, it just takes a bit longer. Hopefully this info will get you started.

 

[Lumpy Grits]

I use a converted OEM, A/C compressor with a 5 gal storage tank.
Has a filter and manual on/off pressure switch(cut-in is 130psi/cut-off is 150psi). Also has a separator to return the oil to the comp.
You want a 'pop-off' valve(175psi)and a filter. You also want a drain on this storage tank.
Use QD couplers for hose and tools. You can vary the compressor speed with a manual throttle on the engine.
I have no problem run'n air tools and can fill my 33" tires in about 90 seconds.
LG

 

[CJim7]

The York is a self oiling compressor. Likewise, some of the Sanden compressors (SD508, SD509) are self oiling. you can tell by the large nut on the cylinder.

I ran an SD508 for several years and it worked great. You DO need an oil/air separator, and just for added security, I ran an air tool oiler in front of the compressor. Use an air pressure gauge, and a Pop-off is highly recommended (I think mine is 120psi) if you use a tank, install a petcock so you can drain any excess moisture out of it. You can either run a line from the intake to your air cleaner assembly or install a lawnmower air filter on the intake.

I run a York now and it needs a rebuild.....pressurization takes longer than it used to . But otherwise, I have been very happy with it also.

I use a 2½ gallon Viair tank under my tub and plumbed two lines to both ends of the Jeep to make reaching tires a breeze.

 

[CJim7]

LG and I are on the same page....lol I forgot about the pressure switch

 

[Lumpy Grits]

I use a round K&N 'breather' filter for the compressor. I also keep a sock over the filter to make real sure the incoming air is clean.
This system has work'd very well for me for 30+ yrs.
LG

 

[Posi]

I did an oil bypass to keep oil from entering the discharge line so there wasn't a need to use an oil separator.



The oil passage needs to be blocked I filled the hole using a wood screw, easy as that.

 

[mriplaybass]

All sounds like good info! I know the Kilby's are nice units, but being an avid do it yourselfer, and also always trying to do it as economically as possibly, I kind of rulled out the kit systems.
A few more questions for everyone. I assume a pressure switch as is used on a shop compressor will work?
I'm not too sure about what to do regarding the oil return when using an OEM compressor.
I will have to do a little research on the various compressors that were recommended, but it sounds like the York is pretty popular.

Posi, I assume that is a York that you posted pictures of. I must be blind, I do not see where you put a sheet metal screw to keep oil from entering the discharge line. Oh yes, next time you post pictures, could you photo shop in some dirt and grime for me? I go out to my shop and feel totally lower class looking at my engine after looking at yours! . Nice work!

I have seen York compressors mounted upright and on their sides. Does this make a difference in the oiling? My experience with AC compressors is Limited to AC.
It has been over 45 years since I had a compressor apart, so memory fails me. Is there a check valve built into the compressor to prevent the air from flowing back into the compressor from the storage tank, or do I need to plumb that in separately?
And one final question, at least for now, is it necessary to install some kind of unloader valve on the pressure side of the compressor? or is the one that is integral to the pressure limit switch adequate?

 

[CJim7]

A few more questions for everyone. I assume a pressure switch as is used on a shop compressor will work?
This is the one thing I purchased from Kilby Enterprises. They're about 24$
I'm not too sure about what to do regarding the oil return when using an OEM compressor.
With the York, wait for posi to resond back Without an oil return, and on many compressors, you will need an oil/air separator. These can be found anywhere that deals with air compressors. You will also need an inline oiler....also found with air compressor stuff
I will have to do a little research on the various compressors that were recommended, but it sounds like the York is pretty popular.

Posi, I assume that is a York that you posted pictures of. I must be blind, I do not see where you put a sheet metal screw to keep oil from entering the discharge line. Oh yes, next time you post pictures, could you photo shop in some dirt and grime for me? I go out to my shop and feel totally lower class looking at my engine after looking at yours! . Nice work!

I have seen York compressors mounted upright and on their sides. Does this make a difference in the oiling? My experience with AC compressors is Limited to AC.
Not to my knowledge.
It has been over 45 years since I had a compressor apart, so memory fails me. Is there a check valve built into the compressor to prevent the air from flowing back into the compressor from the storage tank, or do I need to plumb that in separately?
There is no check valve built in. You will want to install one in-line. Mine is installed just after the exit port.
And one final question, at least for now, is it necessary to install some kind of unloader valve on the pressure side of the compressor? or is the one that is integral to the pressure limit switch adequate?
I use a pop-off valve. they have a ring that you can use to pull open the valve to exhaust excess pressure.

...

 

[Lumpy Grits]

A 'pop-off' valve is designed to open automatically at a set psi and close at a much lower psi.
LG

 

[CJim7]

A 'pop-off' valve is designed to open automatically at a set psi and close at a much lower psi.
LG

A 150psi pop-off works perfectly for releasing pressure on the system. Under 150psi and it stays closed.

 

[CJim7]

 

[Posi]

Posi, I assume that is a York that you posted pictures of. I must be blind, I do not see where you put a sheet metal screw to keep oil from entering the discharge line.

It's not very helpful showing a pic without the screw installed. I must have not taken an after pic, I looked and can't find one. Anyways, look at the pic below again, see the two larger holes, look into the one on the right, [FONT=Arial, Helvetica, sans-serif]beneath the [/FONT] hole to the right is a smaller hole, this is the oil passage. [FONT=Arial, Helvetica, sans-serif]The hole is easily threaded with a #10-32 tap screw. Makes no difference if yours is an upright. I did this mod about 10 years ago. It's very easy, just take the head off, install screw, and put it back on. [/FONT]

 

[Lumpy Grits]

Looks just like the one I use.
LG

 

[duffer]

Here is a list of most items I used. The only Kilby part was a 90 degree Rotolock fitting and most hardware items were sourced through Grainger.

Compressor: York Model 000168, SN: AMC-5461585. Application: 1984 Jeep Wagoneer. 10.3 cu in displacement. Front seal kit: J8120180. Pump manufactured by Borg Warner.

Head output fitting: Kilby 4470 Rotolock to 1/2 NPT 90 degree elbow.

Manifold: Custom machined 6063 aluminum 12 port.

Safety Valve: Control Devices SA25-AMC 150 , Grainger item 5A713, ¼ NPT male thread, AMC 150 psi.

Air Filter: Solberg FS-15-075, modified with custom machined rotolock fitting for direct connection to compressor head threaded suction port. Grainger item 4Z679.

Air Line Filter/Separator: Speedaire 4ZL42, metal with ½ inch NPT connections.

Check Valve/Unloader: Control Devices “Load Genie” PA241A, Grainger item 5A705, ½ inch NPTfemale inlet, ½ inch male outlet.

Pressure Switch: Square D 9013FHG 19J27. 70 - 100 psi factory setting, fixed 30 psi differential. Grainger item 2FG82. ¼ inch male NPT connection. Run it set at 145 psi max.

Air Tank: Linde aluminum medical oxygen tank mounted transverse just ahead of rear axle against bed.

Quick Connects: PCC Series F, 303 stainless steel, ¼ inch female NPT connection. Industrial interchange style (same as Milton M).

While perhaps not necessary, I really like the flexibility of having an adjustable pressure switch.



The mounting in a flat fender with the ubiquitous sbc required a bit of engineering on the mounts to work with the short water pump:

 

[Lumpy Grits]

Very nice set-up!
LG

 

[mriplaybass]

Nice set up! Thanks for the shopping list, should make the project even easier.

 

[tangoalpha]

An unloader valve is a good idea. Should make for an easier start on the compressor and help it live longer. Since we aren't using these compressors for exactly what they were designed for any place to save some wear is probably worth doing. The check valve/unloader combo like duffer used is probably the best way to go. Grainger carries several of these in different price ranges.

 

[Peanut Butter]

I have seen York compressors mounted upright and on their sides. Does this make a difference in the oiling? My experience with AC compressors is Limited to AC.

Yes it does, but only minimally. The original design was for it to be mounted upright. Mounting it sideways minimizes the amount of oil in the base to lubricate the pistons. PS: I use to build Borg Warner York air compressors back in the day (1977).

 

[Posi]

All AMC V8s York compressors were mounted sideways from the factory.
All AMC 6 were mounted upright.
There were far more mounted sideway then upright on AMC engines. Very few were mounted upright.