Installing a Phantom Pump System
Until recently, installing an in-tank fuel pump meant buying a custom tank or doing a lot of dangerous cutting and welding on your tank. Thanks to some ingenuity from Aeromotive, that is no longer the case. The Phantom-series of in-tank pumps allows you to quickly, easily, and safely install an in-tank pump into most stock fuel tanks. The GM A-body tank is a bit problematic when it comes to this install, there is only one good place to locate the pump, so you have to be careful when setting it up.
The main issue with the phantom system is that is needs a fairly flat surface to be installed. Most tanks are corrugated, and Aeromotive knows this. You can install the system on uneven surfaces up to ¼” deep, by way of the included high-density rubber gasket. The A-body tank has pretty deep ribs on it, so on ‘69 and older tanks, the front passenger side is really about the only location you can use. Depending on the model of vehicle, there may or may not be vents at that location. The vent tube runs the length of the tank, so it has to be removed and plugged. There are some variances in the A-body tanks by make, model and year, so plan accordingly.
Before starting with this process, make sure the tank is empty of fuel and it is a good idea to rinse it out with water and dry it out with some compressed air.
Once you have the area picked, you have to cut. We used a 3 ¼” hole saw to make the hole. Go slow and take your time. Most of the metal shavings will stay outside the tank, but you will end up with some inside. That is OK because you should vacuum it out later any way. The kit comes with the necessary drill jig that fits perfectly inside the 3 ¼” hole.
Place the jig in the hole; make sure none of the drill holes run through the angled section of any corrugations in the tank. The mounting studs must be through flat metal. Drill two holes opposite each other, and then use the supplied bolts and nuts to secure the jig in the tank. Once secure, drill the rest of the holes and remove the jig. At this point, you should clean the tank with a vacuum to remove any metal shavings.
Now the foam baffle is cut to size. Measure the tank depth and add 1”. Cut the foam to that length. You want it a little longer than the tank to keep it in place. The kit comes with a stud ring, this installs from the inside of the tank. It is split on one side to go into the hole. Install this and pull the studs through the sheet metal. Drop the drill jig over the studs and loosely thread a couple of nuts onto the studs to hold it in place. Press the baffle through the hole and position the foam around the stud ring.
Using the tank depth measurement, assemble the pump and filter sock and set the max depth to the tank depth. Cut the pump mounting arm to accommodate this depth. It is critical that the pump sock sit on the bottom of the tank, otherwise you can starve the pump for fuel, which will kill it. Cut the supplied fuel hose to match the installed depth and assemble the pump to the housing using the clamps provided. Don’t forget to install the wiring harness.
Slip the gasket into the pump assembly, remove the drill jig, and slide the pump into the tank and drop the housing over the studs on the ring. Thread the nuts and washers onto the studs and tighten them in a criss-cross pattern evenly to seat the housing and not distort or break the studs. You can overtighten the studs and break them, so be careful. Hand tight is all you need, don’t use an impact.
At this point, the tank can be installed in the vehicle. For A-body cars, you will need to space the tank down about a ½” to get the clearance for the pump assembly. You can do this with foam or wood blocks, or fabricate two metal wedges. Unfortunately, this is necessary for clearance. Another option is to cut or dimple the trunk pan over the housing.
With the tank installed, you can wire it up and run the lines. This system is capable of return or returnless plumbing and can be PWM controlled for LT-series or aftermarket ECM control. The housing uses -6 fittings for ease of use with 3/8” hard fuel lines, making it perfect for factory or aftermarket fuel line.
Each Phantom fuel system comes with the baffle, pump, install ring, and all the related hardware. IT installs easily into the A-body tank.
We started by cleaning up the tank and marking the location for the pump. There is really only one suitable spot, the front passenger corner.
Next, the tank was drilled for the center of the mounting hole. We are pre-drilling this because hole saws have a bad habit of breaking or jerking your hand when you go through the metal and the blade catches on the steel. Practice safe drilling.
Now we cut the hole using the correct size hole saw. A good quality bi-metal saw is necessary.
Inside the tank was a long vent tube. Some A-body tanks have this, some just have a short port. We removed the line because it was in the way.
To fill the hole, we ran a ¼-20 tap through the hole.
Then we added some high-strength threadlocker to a stainless steel bolt and threaded it into the hole.
We added a nut and washer on the inside of the tank to help seal the hole. It won’t leak now.
Moving on to the installation, the drill jig was dropped into the hole and aligned so that none of the holes were in the side of a rib (very important), and drilled two opposing holes.
A single bolt was dropped into the two holes to keep the jig from twisting while drilling the rest of the holes.
The tank gets measured to the bottom, and the foam baffle is cut 1-inch longer than the total depth.
The baffle goes inside the tank next. You have to fold it onto itself, but it conforms relatively easily.
To secure the pump housing, the split ring goes into the tank and the studs are aligned and pressed up through the holes previously drilled.
The studs should be fully exposed. The foam baffle goes around the outside of the ring.
The pump gets a filter sock and the rubber sleeve slides over the pump body.
The tank depth is measured again, this time for the pump depth.
That measurement is then transferred to the pump housing and the pump positioned to touch the bottom of the tank.
We cut the rail a little short so that the rail would not impede the placement of the pump.
Because this pump is being used with the LT1 PWM system, the brass plug gets a 1/32” hole drilled into it. This a pressure vent and is only required for PWM returnless usage. This pump works great for return systems without this mod.
Band clamps secure the pump the housing and the fuel line to the top. The wiring simply plugs in.
A foam pad goes onto the top of the studs and then the pump housing drops into the tank. Be careful not to pinch the wires.
Each stud is tightened in a criss-cross manner until the housing is sealed tight. Don’t over-torque them too much because they will break. The wiring is also connected. You can make a quick-connect with spade terminals.
Underneath the car, a section of sound mat should be installed over the pump to absorb any noise from the pump.
The kit comes with some foam padding. The pump is too tall for the car, so we built up the front of the tank with 3 strips of foam in a pyramid shape. This will space the tank down enough to clear the pump.
Before installing the tank, install the fuel lines as well. These short lines will connect to the hard lines under the car. The stock tank straps work perfectly with 1” longer bolts.
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