A few people have been asking if you can convert a regular non-york type air conditioning compressor for use as an onboard air compressor.
The answer is: maybe.
The swash-plate type compressors will make air just fine, like a York, but because they don't have outboard lubrication, you have to oil your compressor each time before you use it. I oil mine before each use, and after every 30 minutes of run-time. This also introduces oil mist to the system, and this oil can end up in your tires. But a coalescing filter can be used to remove this.
On my 97 LX450, I elected to use a corolla a/c compressor because I had a few of them lying around. If you're going out of your way to BUY an a/c compressor, I recommend you get a York one, unless the York is too big to fit in the space that you have. If you have a turbo, or a tight engine bay in a non-80 application (5vz 4Runner, etc) or wish to remove your air conditioning and convert the original a/c comp into an OBA comp, then this is the way to go. Or if you've got a bunch of free but working compressors lying around
First thing I did was install a spare a/c clutch and pulley from an 80 so that the pulley matched what was already on the a/c compressor in the vehicle. Next part, I had my buddy the machinist make a bracket to fit the a/c compressor up high beside the head. By using a much longer belt, I can use a single belt to drive both the a/c compressor and my OBA compressor. The new belt just clears the fan hub by about 1/4" and is tensioned by the original a/c compressor belt tensioner down below. Belt sizing is a bit tricky, it can take a few tries to get it right. Mine's 58" long.
The inlet is a chunk of a/c piping from the donor vehicle. It's about 5/8" diameter, so I installed a K&N push-on filter to keep debris out of the air inlet. It's a slip-on fit, so I pull it off to squirt lube oil into the compressor to keep it happy.
The outlet of my compressor has a AN-10 (5/8 JIC-10) fitting installed on it, allowing me to use hard piping to the manifold with pressure switch and quick-connector. Hard piping also runs down the left side of the engine to a spot next to the transmission. From there, a short length of AN-10 braided hose connects the pipe to the 2-gal air tank. The ends of the piping are all bracketed in place to minimize damage from vibration.
The piping I used is 5/8 aluminum 'fuel pipe' that you can get from summit racing and other racecar supply shops. It's easily formed by hand so there is no need for a pipe bender. The brass ends I used are from Home Depot, for 5/8 flare connections, which happen to also be JIC-10 and AN-10 compatible. If you prefer anodized aluminum, You can use AN-10 tube nuts to match the aluminum tubing. The brass ones are cheaper, and I didn't want red and blue racecar stuff hanging off my non-racecar engine. You will need a pipe flaring tool to install the tube nuts and fittings.
The tank is important to reduce compressor surge, and to reduce the on/off switching of the compressor clutch. The less on/off switching there is, the longer the clutch will last. It is, after all, a friction clutch. And a tiny one at that. For tire inflation there is no advantage to using a huge tank over a tiny one. 2-gal tanks are small, easy to hide, and relatively affordable. You can even raid an old 110v compressor for the tank if you want.
The tank I used is from Firestone, for their airbag systems. You can use any tank and fit it anywhere on the vehicle. I prefer NOT to install compressed air stuff in the cabin of the truck. Choose a well-protected spot underneath somewhere. Mine lives under the driver's seat on the outside of the frame rail. The sliders offer adequate protection, but a small plate will be added to the slider soon.
Pressure switches are available from various sources. VIAIR and firestone and all the low-rider airbag supply companies can supply you with a low-current switch. Mine is a 80/110 and totally adequate for tire inflation or running air tools.
My manifold is a simple block of aluminum with ORB-8 bosses and some 1/8NPT and 1/4NPT ports. I bolted mine to the engine removal loop, and used a 1/8" roll-pin to keep it from rotating. If I need to pull the engine, the manifold will unbolt and allow full use of the hanging loop. ORB-8 to JIC-10 adapters are cheap and easy. Any hydraulics supply shop will have these for a few bucks each. If you don't have a way to make ORB-8 bosses, you can simply tap them with 3/8NPT and use NPT-JIC adapters. Same deal.
A hand throttle is very handy when using any form of engine-driven OBA. Remember that your output doubles at 1500 rpm versus at idle speeds!
Some day I will permanently wire this thing up, with an interior switch and all that, and a pressure gauge in the dash. Some day.
In the mean time, this system is fully functional. And since I open the hood to oil the compressor and hook up my coily air hose, I use a jumper wire between the pressure switch and the (+) positive terminal of my battery.
The answer is: maybe.
The swash-plate type compressors will make air just fine, like a York, but because they don't have outboard lubrication, you have to oil your compressor each time before you use it. I oil mine before each use, and after every 30 minutes of run-time. This also introduces oil mist to the system, and this oil can end up in your tires. But a coalescing filter can be used to remove this.
On my 97 LX450, I elected to use a corolla a/c compressor because I had a few of them lying around. If you're going out of your way to BUY an a/c compressor, I recommend you get a York one, unless the York is too big to fit in the space that you have. If you have a turbo, or a tight engine bay in a non-80 application (5vz 4Runner, etc) or wish to remove your air conditioning and convert the original a/c comp into an OBA comp, then this is the way to go. Or if you've got a bunch of free but working compressors lying around
First thing I did was install a spare a/c clutch and pulley from an 80 so that the pulley matched what was already on the a/c compressor in the vehicle. Next part, I had my buddy the machinist make a bracket to fit the a/c compressor up high beside the head. By using a much longer belt, I can use a single belt to drive both the a/c compressor and my OBA compressor. The new belt just clears the fan hub by about 1/4" and is tensioned by the original a/c compressor belt tensioner down below. Belt sizing is a bit tricky, it can take a few tries to get it right. Mine's 58" long.
The inlet is a chunk of a/c piping from the donor vehicle. It's about 5/8" diameter, so I installed a K&N push-on filter to keep debris out of the air inlet. It's a slip-on fit, so I pull it off to squirt lube oil into the compressor to keep it happy.
The outlet of my compressor has a AN-10 (5/8 JIC-10) fitting installed on it, allowing me to use hard piping to the manifold with pressure switch and quick-connector. Hard piping also runs down the left side of the engine to a spot next to the transmission. From there, a short length of AN-10 braided hose connects the pipe to the 2-gal air tank. The ends of the piping are all bracketed in place to minimize damage from vibration.
The piping I used is 5/8 aluminum 'fuel pipe' that you can get from summit racing and other racecar supply shops. It's easily formed by hand so there is no need for a pipe bender. The brass ends I used are from Home Depot, for 5/8 flare connections, which happen to also be JIC-10 and AN-10 compatible. If you prefer anodized aluminum, You can use AN-10 tube nuts to match the aluminum tubing. The brass ones are cheaper, and I didn't want red and blue racecar stuff hanging off my non-racecar engine. You will need a pipe flaring tool to install the tube nuts and fittings.
The tank is important to reduce compressor surge, and to reduce the on/off switching of the compressor clutch. The less on/off switching there is, the longer the clutch will last. It is, after all, a friction clutch. And a tiny one at that. For tire inflation there is no advantage to using a huge tank over a tiny one. 2-gal tanks are small, easy to hide, and relatively affordable. You can even raid an old 110v compressor for the tank if you want.
The tank I used is from Firestone, for their airbag systems. You can use any tank and fit it anywhere on the vehicle. I prefer NOT to install compressed air stuff in the cabin of the truck. Choose a well-protected spot underneath somewhere. Mine lives under the driver's seat on the outside of the frame rail. The sliders offer adequate protection, but a small plate will be added to the slider soon.
Pressure switches are available from various sources. VIAIR and firestone and all the low-rider airbag supply companies can supply you with a low-current switch. Mine is a 80/110 and totally adequate for tire inflation or running air tools.
My manifold is a simple block of aluminum with ORB-8 bosses and some 1/8NPT and 1/4NPT ports. I bolted mine to the engine removal loop, and used a 1/8" roll-pin to keep it from rotating. If I need to pull the engine, the manifold will unbolt and allow full use of the hanging loop. ORB-8 to JIC-10 adapters are cheap and easy. Any hydraulics supply shop will have these for a few bucks each. If you don't have a way to make ORB-8 bosses, you can simply tap them with 3/8NPT and use NPT-JIC adapters. Same deal.
A hand throttle is very handy when using any form of engine-driven OBA. Remember that your output doubles at 1500 rpm versus at idle speeds!
Some day I will permanently wire this thing up, with an interior switch and all that, and a pressure gauge in the dash. Some day.
In the mean time, this system is fully functional. And since I open the hood to oil the compressor and hook up my coily air hose, I use a jumper wire between the pressure switch and the (+) positive terminal of my battery.
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