Radium Engineering Walbro F90000274 E85 FCST 2 Surge Tank Pumps and 1 Lift Pump

Since 2010, Radium Engineering has been leading the charge in eliminating fuel starvation issues in racing environments. In 2013, they took it a step further by launching the first generation Fuel Cell Surge Tank (FCST), which quickly became the go-to fuel system for professional racers. Designed to simplify plumbing and packaging, it's a game-changer for anyone serious about performance on the track.

What Exactly is a FCST?

The Fuel Cell Surge Tank is a drop-in fuel pump system that's compatible with Radium Engineering's renowned fuel cells or any fuel cell that features the standard 6x10 24-bolt fill plate bolt pattern. This system is specifically crafted to protect EFI vehicles from fuel starvation, ensuring that your engine gets the fuel it needs when it matters most. Unlike traditional trap door boxes with baffles, the FCST boasts a true dual-chamber fuel tank that incorporates a single lift pump and up to three surge tank pumps, all snugly packaged inside the fuel cell. This means you get all the advantages of an external fuel surge tank without the hassle of complex plumbing and safety concerns.

Compatibility Check: Will It Fit My Fuel Cell?

Before you get too excited, let's make sure the Radium Engineering FCST will fit your fuel cell. Here are the criteria you need to check:

• The fuel 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 depth of the fuel cell must be at least 7.7" (196mm) from the outer top face to the internal bottom face.

How Does It Work?

The magic happens when the lift pump scavenges fuel from the bottom of the fuel cell and pumps it into the 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. If the lift pump ever runs low on fuel, the surge tank's volume ensures that the surge tank pumps remain fed, keeping your engine running smoothly. Plus, the return from the pressure regulator helps keep the surge tank canister topped off.

You'll find three fill valves integrated at the bottom of the surge tank. These one-way FKM fill valves stay sealed unless 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 the levels balance out. Any excess fuel simply overflows back into the fuel cell, all while keeping everything safely contained.

Standard Fittings

Here’s a quick overview of the fittings you'll find:

• Pump Out -8AN Male: This is the external fuel pump outlet, marked by the "PUMP OUT" engraving. It features 7/8"-14 threads, making it compatible with all 10AN ORB fittings. The FCST comes standard with a common 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 compatible with all 8AN ORB fittings. The FCST includes a standard 8AN ORB to 6AN male adapter fitting.
• Vent -8AN Male: The external "VENT" port is tapped with 1-1/16"-12 threads for compatibility with all 12AN ORB fittings. The FCST is equipped with Dynamic Safety Vent (DSV) Valves, which utilize a common 8AN male outlet fitting for standard fuel filling.

Selecting Your FCST

The different FCST part numbers vary based on the brand and quantity of fuel pumps. When choosing your fuel pump configuration, pick a combination that can adequately support your engine's output.

Features That Make a Difference

Radium Engineering has fine-tuned the FCST over the years into a reliable and highly functional piece of equipment. Here’s what you can expect:

• 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, ensuring the surge tank stays full.
• Multiple pump options available including gerotor, turbine, and brushless DC motor pumps.
• High-current stainless steel electrical studs that are hermetically sealed to handle all pumps.
• Simplified servicing features that eliminate the need for nylon sealing washers and fuel cell retaining brackets.
• Full CNC aluminum construction 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?

When you choose an FCST, you’ll receive the following items as standard, based on your selected part number:

• 8AN DSV (Dynamic Safety Vent) valve
• 6x10 24-hole FKM gasket
• 6AN male return fitting (other sizes sold separately)
• 8AN male pump out fitting (other sizes sold 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: This package includes 2 surge tank pumps and 1 lift pump.