Modern Rodding

A Tank Full: Swapping Your Chevelle Gas Tank to Accept Fuel Injection or Just Upgrade is a Worthwhile Project

1. Geoff Jones at Hot Rods By Dean is positioning our Classic Performance Products (CPP) complete fuel injection–ready gas tank under our project ’64 Chevelle.

As Seen in the June 2022 Issue of Modern Rodding Magazine

BY BRIAN BRENNAN, PHOTOGRAPHY BY THE AUTHOR

Maintaining a clean fuel system is imperative to keeping your hot rod running. In our case, we have a ’65 Chevelle in need of a fresh tank and one that will handle the performance demands going forward. (This tank will also work on ’64-67 A-body cars.)

One of the major fuel system components is the gas tank. It’s here we incorporated a Complete Fuel Injection Ready Tank Kit with a 24-gallon tank (PN MS6467CFIT-K) from Classic Performance Products (CPP) that will be up to the demands of our EFI-equipped motor. The CPP tank kit includes a 255-LPH in-tank pump that supports up to 600 hp. You can also order an optional high-volume pump with the proper installation components ready to handle your higher horsepower needs. Something else to keep in mind as this gas tank system will work very well with your small-block Chevy or an LS motor. It should also be noted should you have a carburetor this CPP gas tank will work just fine. However, to make the system work properly you will need to use a different filter/regulator setup. The main issue here is to regulate the fuel pressure down from approximately 58 psi to something along the lines of 5-7 psi. The CPP fuel filter/regulator provided is factory set at 58 psi. It should be noted that the pump included in the CPP kit unregulated can push upwards of 100 psi but the flow rate will drop significantly. Additionally, the adjustable-external regulator would be accompanied by a separate inline fuel filter. (Should you be wanting to run one of the LT family of motors there’s a separate system required because of the fuel delivery demands. We will come back and visit this same CPP gas tank, but this time set up for an LT V-8 later.) Next stop was onto Hot Rods By Dean to work with Geoff Jones to take care of the installation.

Related Article: A CPP Brake Booster Kit Solves Two Problems with One

There are four major components to a fuel system: a fuel tank, a pump, a filter/regulator, and injectors or carburetor, and they are responsible for delivering fuel to the engine as needed. Each component must perform flawlessly to achieve expected vehicle performance and reliability. Something to keep in mind. Before installation the gas tank should be checked for internal cleanliness. It is always a good idea to visually inspect the tank. Since you are starting with a brand-new tank this should be quick and easy. Where we hot rodders get into trouble occurs when we paint or polish the tank before use. Should you do either you need to carefully inspect the inside of the tank for metal debris or anything left over from the painting process.

It’s not as unusual as you may think, this “failure to launch” because of a fouled fuel system. After all the effort, time, and money the last thing you want is to pollute the new EFI with contaminated fuel. Most of us understand that if you take a running hot rod and swap the carb for an EFI the odds are you will need to modify your existing tank, or replace it with an EFI-appropriate tank.

Aside from the tank, get ready to have two fuel filters. One will be in the tank and one will go after the pump and before the EFI. (There are fuel pumps designed to be external, but we have found the internal pumps have advantages, so we went with the internal pump.) Most modern vehicles with fuel-injection systems use filters rated between 10 and 30 microns.

A word on microns: Very fine sand is 62 microns (0.0025 inch). If you have a coffee maker, think of its paper filter, it’s approximately 20 microns. This may vary but you get the idea. Typically, an in-tank filter (before the pump) should be in the range of 25 to 400 microns. This filter is protecting the pump from damage. Next up is the final filter (after the pump), which is 1 to 40 microns. (If you have a high-performance EFI system you may be looking at filters that are capable of 10 microns or finer filter.

Moving onto the tank installation. You will want to test-fit your CPP fuel-injection ready tank; make sure it is properly grounded to the frame and be prepared to install an inline fuel filter/regulator. Once the installation is complete keep in mind not to overfill the tank. You will want to leave room for fuel to expand when it warms up via raised ambient air temperature.

Should you be using a non-vented cap, as we did, you will need a vent on your tank or filler neck. In our case, the vent is in the tank. The vent should be as high as the highest point on the tank, which includes the filler neck. Make sure there are no dips in the vent line, otherwise you have introduced the possibility of trapping fuel or condensation.

Part of the CPP kit is a remote-mount rollover vent valve, which performs two vital functions. As part of the gas tank’s vent system, it will allow the gas tank to breathe and not build up pressure or vacuum during operation. The second, and arguably a more important function, is to prevent gasoline from flowing onto the ground from the tank resulting from a rollover incident. A check ball inside the valve will close to prevent gas from running out. Note there are two types of rollover valves: in-tank and remote. The remote-mount rollover style is provided with the CPP kit. It comes with a screen to assist in keeping out contaminates from your line and tank. It should be noted that not all rollover vent valves come with this feature.

As for the actual installation of the tank itself it’s quite simple. The factory tank and your replacement tank should mirror each other’s installation. You will find two tank straps provided in the kit, as they are longer than the stock straps. You can use the gas tank’s original hardware to hold the new longer straps in position. (El Caminos can maintain the use of the original factory straps.)

As an aside you will want to note the ohm reading of your gas gauge. For instance, should your gauge be stock, such as our ’65 Chevelle, we ordered the CPP VSU-3 sending unit that handles 0-30 ohm. (If you have a ’65 Chevy factory gauge you will need to check. This-year-only gas gauges came with either 0-30 or 0-90 ohm. Clearly a production change at some point during the year.) If you were to have an aftermarket gas gauge such as a set of Classic Instruments standard round universal gauges, then you would order CPP VSU-240 that handles 240-330 ohm reading. FYI on stock gauges: GM ’64 and earlier the reading would be 0-30 ohm; in 1966 and later the reading would be 0-90 ohm. Ford 1987 and later gauges would be 16-158 ohms; Ford 1986 and earlier would be 73-10 ohms.

As a side note: You will always want to test your sending unit before tank/sending unit installation to make sure it correctly corresponds with your gas gauge. Make sure to follow the CPP directions closely when setting up the in-tank fuel pump assembly.

The tank itself is mounted via the two lengthened straps. The kit comes with all the necessary hardware and components, such as the fuel pump and both in-tank and external fuel filter/regulator. There is ample hose (intended to be used with today’s gasoline) and push-to-lock line fittings, remote rollover valve, the filler neck, and gas gauge sending unit. When mounting the remote rollover valve make sure that it is mounted to the frame or bracket that places it higher than the top of the tank. The tank should also be mounted vertical to the rollover valve.

Follow along with our Project ’65 Chevelle and see how easy it is to install the CPP Complete Fuel Injection-Ready Tank Kit. This 24-gallon tank will match up well with the demands of our Chevelle going forward. Stay tuned, there is a lot more to do on our Chevelle.

2. The CPP Complete Fuel Injection Ready Tank Kit (PN MS6467CFIT-K) includes a 255-LPH in-tank pump that supports up to 600 hp. There’s an optional high-volume pump to handle higher horsepower requirements. (For LT motors there is a different tank/fuel delivery system.)
3. Aside from the CPP tank the kit comes complete with all the necessary hardware (PN CPFIIK-255), such as hose and “push to connect” fittings that require no specialty tools. Internal fuel pump with internal and external filter/regulator, fuel float, and sending unit.
4. Here you can see the cork gasket that goes between the pump mounting plate and the tank. Also, note the electrical connection that comes off the top of the pump and attaches to the connection points located on the mouthing plate.
5. Note the filter sock that is attached to the bottom of the pump. It snaps into position and the “white” return line should be cut approximately 1/2 inch above the sock.
6. Here is the “white” return fuel hose that is tie-wrapped to the fuel pump (covered by its protective “coat”).
7. There is a cork gasket that goes between the tank and both rings that mount, as in this case, the fuel pump, lines, and electrical hookups. Make sure to use PTFE Teflon pipe tape; it’s required on all threaded surfaces.
8-9. The fuel pump/filter drops through the provided hole in tank. Note it houses the output, return lines, as well as the vent line.
10. There is a tank vent nipple provided. Make sure to run the hose (part of the CPP kit) too, or better yet above the filler neck opening.
11-14. The gas sending unit plate has a distinct hole pattern. Make sure to note that and it will save you from starting the installation only to find out that you are a “hole” off.
15. The “Y” fitting is supplied to plumb together the vent from the tank and the vent from the fuel pump assembly. Make sure to install the “Y” fitting as high in the system as possible. Ideally, combine both vent lines just before entering the remote rollover vent valve.
16. The CPP remote rollover vent valve is extremely import to both a safe and properly functional fuel delivery system. Make sure to mount it correctly (note instructions).
17. CPP provides ample push to connect fittings for a very neat and good-looking connection. No special tools are required.
18-19. The CPP external fuel filter/regulator is factory set at an ideal 58 psi and has a ground strap that goes from the bracket, where the electrical connections enter the filter/regulator, and then attach to the mounting hole (note arrow) portion of the bracket. This provides a secure ground to the frame.
20. The CPP-provided external fuel pump/regulator affixes to the frame. Remember to also drill a pilot hole so that the tang on the bracket can locate within the drilled hole, thus preventing the filter/regulator bracket from moving.
21-22. CPP provides a pair of new lengthened straps that attach in the rear position (closest to the front of the car) utilizing the factory slots in the frame.
23. Although you can use the original hardware, we opted for new hardware for our installation. At the front of the tank (nearest rear bumper) a pair of drop-down threaded bolts and nuts are used to hold the forward portion of the tank within the straps.
24. The shorty metal filler neck and rubber boot are supplied in the CPP kit.
25-26. We used a factory-style sealed gas cap necessitating the use of a remote-mounted rollover vent valve. The CPP model comes with a filter screen to help prevent unwanted material from entering the tank.
27. The finished installation features our CPP 24-gallon tank (PN MS6467CFIT-K) in its resting position and ready to go. Remember, check all your connections both to fuel and electrical. Take a short test drive and come back and check again. Safety first!
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