Kilby Enterprises uses the...
Kilby Enterprises uses the twin-piston York 10.3ci compressors that are capable of 4 cfm at 90 psi while running at 1,200 rpm. They can also produce a whopping 8 cfm with a bit more engine speed, plenty of air to fill up tires fast or run air tools.
A simple fact of life on the trail is that once you air down your tires for better traction in the dirt, you have to get air back into them before hitting the pavement-unless horrible handling and blown tires are your thing. Lots of compressors are out on the market nowadays to assist you in getting your tires back to street pressure. However, many of them are somewhat slow, and can make airing back up a long ordeal. Some also have short duty cycles that require the compressor to stop and rest every now and then to cool. This adds to the already long airing-up time. Most also do not have the capacity to run air tools.
There is a compressor out there, though, that can run all day and fill up a tire rapidly. It can even run air tools without any problems. What is this magic new product? Well, actually, it has been around for quite a while in the form of your vehicle's air-conditioning compressor. These powerful compressors move a lot of air and can be run pretty much all day long.
Finding one in good condition can be a chore, though, and adapting one to a vehicle can also be a headache, as there is a lot to be figured out. Luckily, the folks at Kilby Enterprises have everything you need to assemble a complete kit to put a powerful engine-driven compressor into your vehicle. From fittings to brackets to regulators to tanks and complete compressors-Kilby Enterprises has everything. The company will sell parts individually or can custom-tailor a whole kit to fit your application. We followed along as Kilby technicians put one of the company's systems on a Jeep TJ.
 Kilby also manufactures the...  Kilby also manufactures the brackets necessary to adapt the compressor to the engine. Applications include most Jeep TJs and YJs with or without air conditioning, Jeep XJs, '78-'86 Jeep CJs without air conditioning, Dodge V-10s and the Cummins 24-valve engine. Chevy folks with '88-'96 small-blocks are also covered, and so are '87-'96 Ford Bronco owners. |  Kilby's fittings also are...  Kilby's fittings also are handy. They are made to utilize 1/2-inch NPT connections but can also be made for Rotolock fittings to fit Tube-O compressors. |  To drive the York compressor,...  To drive the York compressor, Kilby makes this new alternator pulley that is fitted with an extra groove for another belt. |
 The TJ we were using for this...  The TJ we were using for this install already had air conditioning, so the bracket puts the new York compressor to the outside of the factory air-conditioning compressor. If the TJ didn't have A/C, the York would have mounted where the factory A/C compressor is located. |  The next item that is used...  The next item that is used is an oil-removal filter that was attached to the firewall. It is used because the compressor naturally blows oil that needs to be filtered out. Also visible in this photo is a check valve that is basically a one-way valve and not needed if you are not running an air tank. |  A pressure switch was next...  A pressure switch was next to be plumbed into the system. Its job is to turn the compressor on and off. Kilby uses units that feature an adjustable cut-off pressure. This one was set to shut off at 150 psi. |
 To hold air in reserve, a...  To hold air in reserve, a 2.5-gallon air tank was installed under the TJ. Kilby also offers 1.75-gallon and 1.25-gallon tanks that are a bit smaller in dimension for space constraints. |  Finally, coupler fittings...  Finally, coupler fittings were put on the front and rear of the Jeep. These are handy because you can just plug an air hose or air tool right into them. |  The On-Board Air system can...  The On-Board Air system can also be used to run ARB Air Lockers in addition to airing up your tires and running your air tools. When plumbed into an ARB, a separate regulator is used to make sure the pressure is right. |
 Depending on your application,...  Depending on your application, some modification to the vehicle's sheetmetal might be necessary. On this TJ, some removal of the inner fenderwell to clear the new compressor was required. |  The York compressors are fast....  The York compressors are fast. This one filled up this 35x12.50-inch tire from 8 psi to 30 psi in 50 seconds at idle. If that is not quick enough for you, the engine rpm can always be raised. | |