Radium Engineering Walbro F90000267/274/285 E85 FCST Without Pumps

Since 2010, Radium Engineering has been at the forefront of tackling fuel starvation issues that racers face. In 2013, they took a significant step forward by introducing the Fuel Cell Surge Tank (FCST), which quickly became the go-to choice for professional racing. It's designed to simplify plumbing and packaging, making it a favorite among competition vehicles.

What Exactly is a FCST?

The Fuel Cell Surge Tank is a drop-in fuel pump system tailored for Radium Engineering's popular fuel cells or any fuel cell that adheres to the industry-standard 6x10 24-bolt fill plate bolt pattern. This innovative system is engineered to protect EFI vehicles from fuel starvation. Unlike a basic trap door box with baffles, the FCST features a genuine dual-chamber fuel tank that utilizes a single lift pump and can accommodate up to three surge tank pumps, all neatly packaged inside the fuel cell. This design offers all the advantages of a traditional external fuel surge tank without the associated safety concerns or plumbing complexities.

Is This Compatible with My Fuel Cell?

To ensure a smooth installation of the Radium Engineering FCST into your fuel cell, please check that the following criteria are met:

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

How Does It Work?

A lift pump draws fuel from the bottom of the fuel cell and pumps it into a 2L surge tank. Inside this surge tank canister, you can install up to three EFI fuel pumps to supply high-pressure fuel to your engine. If the lift pump runs low on fuel, the surge tank's internal volume keeps the surge tank pumps fed, ensuring your engine has the fuel it needs. Plus, the return from the pressure regulator is directed back to the surge tank canister, helping to maintain its fullness.

You'll find three fill valves integrated 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, allowing 355LPH of fuel (totaling 1065LPH) to flow into the surge tank until equilibrium is reached.

Any excess fuel in the surge tank simply flows back into the fuel cell, all happening safely within the confines of the fuel cell.

Standard Fittings

Pump Out -8AN Male

The "PUMP OUT" port is marked clearly and 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

The "RETURN" port is designed for low-pressure fuel returning from the FPR, using 3/4"-16 threads for compatibility with all 8AN ORB fittings. You'll also find a standard 8AN ORB to 6AN male adapter fitting included.

Vent -8AN Male

The "VENT" port is tapped with 1-1/16"-12 threads, compatible with all 12AN ORB fittings. The FCST is equipped with Dynamic Safety Vent (DSV) Valves that utilize a common 8AN male outlet fitting for standard fuel filling.

Selecting Your FCST

The various FCST part numbers correspond to the brand and number of fuel pumps. When selecting a fuel pump configuration, choose a combination that can adequately support your engine's output.

Features

Radium Engineering has consistently refined the FCST over the years, creating a robust and highly functional piece of hardware:

• Merged single 10AN ORB female threaded outlet, with all pumps featuring check valves to prevent back-flow in multi-pump setups.
• One-way fill valves located at the bottom of the canister that allow fuel in but prevent it from flowing out, keeping the surge tank full.
• Multiple fuel pump options are available, including gerotor, turbine, and brushless DC motor pumps.
• High-current stainless steel electrical studs are hermetically sealed to handle all pumps.
• Simplified servicing features eliminate the need for nylon sealing washers and fuel cell retaining brackets.
• Constructed entirely from 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 with the following standard components, tailored per part number:

• 8AN DSV (Dynamic Safety Vent) valve
• 6x10 24-hole FKM gasket
• 6AN male return fitting (additional sizes available separately)
• 8AN male pump out fitting (additional sizes available 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

Note:

• Pumps Not Included