Radium Engineering Walbro F90000274 E85 FCST 3 Surge Tank Pumps & 1 Lift Pump

Since 2010, Radium Engineering has been a game-changer in the world of racing with their external fuel surge tanks. These tanks are designed to tackle the frustrating issue of fuel starvation that can happen during high-performance driving. Fast forward to 2013, and Radium introduced the Fuel Cell Surge Tank (FCST), which quickly became the go-to choice for professional racers looking for reliability and performance.

What Exactly is a Fuel Cell Surge Tank (FCST)?

The FCST is a drop-in fuel pump system that fits seamlessly into Radium Engineering's popular fuel cells, as well as any fuel cell that follows the industry-standard 6x10 24-bolt fill plate pattern. It's specifically crafted to safeguard EFI vehicles from fuel starvation. Unlike typical trap door boxes with baffles, the FCST features a true dual-chamber design, incorporating one lift pump and up to three surge tank pumps—all neatly packaged within the fuel cell. This means you get all the advantages of an external fuel surge tank without the headaches of complex plumbing or safety concerns.

Is the FCST Compatible with My Fuel Cell?

To ensure the Radium Engineering FCST fits perfectly into your fuel cell, here are a few important points to check:

• The cell must have the standard 6"x10" 24-bolt flange opening.
• The opening needs to be on the top face of the fuel cell (not on a side face).
• The cell depth should be at least 7.7" (196mm) from the outer top face to the internal bottom face.

How Does It Work?

Here’s the magic: a lift pump draws fuel from the bottom of the fuel cell and sends it into a 2L surge tank. Inside this surge tank canister, you can install up to three EFI fuel pumps that deliver high-pressure fuel to your engine. In the event that the lift pump runs dry, the surge tank still has enough fuel to keep your engine running smoothly. Plus, the return from the pressure regulator goes back to the surge tank to help maintain its fuel level.

As shown in the design, there are three fill valves at the bottom of the surge tank. These one-way FKM fill valves remain sealed until the fuel level in the cell rises above that in the surge tank. When that happens, each valve opens up, allowing 355LPH of fuel (that’s a total of 1065LPH!) to flow into the surge tank until everything balances out. Any excess fuel simply flows back into the fuel cell, keeping everything safe and secure.

Standard Fittings

• Pump Out -8AN Male: This is the external fuel pump outlet port, marked with "PUMP OUT." It features 7/8"-14 threads, making it compatible with all 10AN ORB fittings. The FCST comes with a standard 10AN ORB to 8AN male adapter fitting.
• Return -6AN Male: Used for low-pressure fuel returning from the FPR, this port has 3/4"-16 threads and is compatible with all 8AN ORB fittings. It includes an 8AN ORB to 6AN male adapter fitting.
• Vent -8AN Male: The external "VENT" port is tapped with 1-1/16"-12 threads, fitting all 12AN ORB fittings. The FCST includes Dynamic Safety Vent (DSV) Valves, which use a common 8AN male outlet fitting for standard fuel filling.

Selecting Your FCST

The different FCST part numbers correspond to the brand and quantity of fuel pumps included. When choosing a configuration, make sure to select a combination that can meet your engine's power requirements.

Features

Radium Engineering has spent years refining the FCST, resulting in a robust and functional piece of equipment:

• Merged single 10AN ORB female threaded outlet, with check valves to prevent back-flow in multi-pump setups.
• One-way fill valves at the bottom of the canister that allow fuel in but not out, keeping the surge tank full.
• Multiple fuel pump options, including gerotor, turbine, and brushless DC motor pumps.
• High-current stainless steel electrical studs that are hermetically sealed to accommodate all pumps.
• Simplified servicing features that eliminate the need for nylon sealing washers and fuel cell retaining brackets.
• Constructed from full CNC aluminum with anodized surfaces for superior corrosion resistance.
• Compatible with leaded and unleaded gasoline, methanol, ethanol, E85, and more.
• Dynamic safety vent valve with rollover protection and fuel fill shut-off protection.
• Optional fuel surge tank level switch and diagnostic LED failsafe port.

What’s in the Box?

Every FCST variation comes standard with the following items, tailored to your specific part number:

• 8AN DSV (dynamic safety vent) valve
• 6x10 24-hole FKM gasket
• 6AN male return fitting (other sizes must be purchased separately)
• 8AN male pump out fitting (other sizes must be purchased separately)
• Fuel level sensor block-off plate
• Fuel level switch block-off plug
• Three FKM one-way fill valves
• Stainless steel mounting hardware
• Insulated anodized aluminum acorn nuts
• Electrical power wire ring terminals
• Links for compatible fillers (not included), Direct Mount or Remote Mount

• Includes 3 Surge Tank Pumps and 1 Lift Pump