BACKGROUND
Since 2010, external Radium Engineering fuel surge tanks have been an excellent way to eliminate fuel starvation that occurs in racing. To simplify plumbing and packaging, in 2013 Radium Engineering introduced the first generation Fuel Cell Surge Tank (FCST) to the competition vehicle market. It quickly became the preferred fuel system for professional racing.


WHAT IS A FCST?
The Fuel Cell Surge Tank is a drop-in fuel pump system for Radium Engineering's popular fuel cells or any cell that uses the industry standard 6x10 24-bolt fill plate bolt pattern. The FCST is designed to protect EFI vehicles that experience fuel starvation. It is NOT a glorified trap door box with baffles. It features a true dual-chamber fuel tank utilizing a single lift pump and up to 3 surge tank pumps all packaged inside the fuel cell. It provides all the benefits of a traditional external fuel surge tank without safety concerns and plumbing complexity.



IS THIS COMPATIBLE WITH MY FUEL CELL?
To install a Radium Engineering FCST into a fuel cell, the following criteria must be met:
1. The cell must have the industry standard 6"x10" 24-bolt flange opening.
2. The opening must be on the top face of the fuel cell (i.e. not a side face).
3. The cell depth must be at least 7.7" (196mm) measured from the outer top face to the internal bottom face.


HOW IT WORKS
A lift pump scavenges fuel from the bottom of the fuel cell and pumps it into the 2L surge tank. Inside the surge tank canister, up to 3 EFI fuel pumps can be used to feed high pressure fuel to the engine. If the lift pump starves, the volume inside the surge tank canister will keep the surge tank pumps fed and the engine supplied with fuel. The return from the pressure regulator is also routed to the surge tank canister to help keep it full.

There are 3 fill valves integrated to the bottom of the surge tank. These 1-way FKM fill valves are sealed shut unless the fuel level in the cell rises above the fuel level in the surge tank. If this happens, each fill valve opens and sends 355LPH of fuel (1065LPH total) into the surge tank until fuel level reaches an equilibrium.

Excess fuel in the surge tank simply overflows back into the fuel cell. This dynamic sequence is all done inside the safety of a fuel cell.


FEATURES
Over the years, Radium Engineering has continued to refine the FCST into a robust and highly functional piece of hardware.

-Merged single 10AN ORB female threaded outlet. All pumps use check valves that prevent back-flow in multi-pump applications.
-One-way fill valves located on the bottom of the canister that allows fuel in, but not out, keeping the surge tank full.
-Multiple fuel pump options including gerotor, turbine, and brushless DC motor pumps.
-Hermetically sealed high-current stainless steel electrical studs capable of handling all pumps.
-Simplified servicing features eliminating nylon sealing washers and fuel cell retaining brackets.
-Full CNC aluminum construction with anodized surfacing for superior corrosion resistance.
-Fuel compatibility: leaded and unleaded gasoline, methanol, ethanol, E85, etc.
-Dynamic safety vent valve with rollover protection and fuel fill shut-off protection.
-Optional fuel surge tank level switch and diagnostic LED failsafe port.


STANDARD FITTINGS

PUMP OUT -8AN MALE
The external fuel pump outlet port is signified by the "PUMP OUT" engraving. It uses 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. However, various 10AN ORB adapter fittings can be purchased.

RETURN -6AN MALE
The external "RETURN" port is used for low pressure fuel returning from the FPR. This port uses 3/4"-16 threads making it compatible with all 8AN ORB fittings. The FCST comes standard with a common 8AN ORB to 6AN male adapter fitting. However, various 8AN ORB adapter fittings can be purchased.

VENT -8AN MALE
The external "VENT" port is tapped with 1-1/16"-12 threads making it compatible with all 12AN ORB fittings. The FCST comes standard with 20-0435 which uses a common 8AN male outlet fitting for standard fuel filling. However, 20-0535 can be purchased separately with a 12AN male fitting for quick fill dry break systems that require a high-flow vent.


WHATS IN THE BOX?
The following comes standard with every FCST variation configured per 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 1-way fill valves
-Stainless steel mounting hardware
-Insulated anodized aluminum acorn nuts
-Electrical power wire ring terminals
-3 Surge Pump Walbro GSS342
-1 Lift Pump Walbro GSS342
-Links for compatible fillers (not included), Direct Mount 20-0197-V or Remote Mount 20-0505-V and 20-0547.


20-099X-XX FCST
The 20-099X-XX Fuel Cell Surge Tanks utilize new design features that reduce overall weight by 35.3%. These new additions also improve assembly time. They also use stronger stainless steel lift pump mounting brackets. Furthermore, they are compatible with Radium Engineering's shrouded fuel level sensors.

With exception to the brushless E5LM variation, these FCSTs are available with and without fuel pumps included. The lift pump is always matched to be the same style pump(s) found inside the fuel surge tank canister. Any option that lists "Pump Included" comes pre-assembled with new fuel pumps and filters installed.


WHAT ELSE IS NEEDED?

FUEL CELL
A fuel cell is not included with the FCST. The fuel cell MUST use a 6x10, 24-bolt fill plate flange. The distance from the outer top face to the internal botton face must be at least 7.7" (196mm). The distance from the top of the fuel cell to the bottom of the lift pump filter (lowest point of the kit) is adjustable. However, if the fuel cell is deeper than 10 inches, purchase this Lift Pump Extension.

FUEL FILLER
The fuel filler pattern uses an industry standard 6-bolt (2.18" B.C.) flange. Radium Engineering has them for both direct filling Radium part number 20-0197-V and remote filling Radium part numbers 20-0505-V and 20-0547.

VENT HOSE
A hose and/or filter must be connected to the "VENT" port fitting. For compatible vent kits and more information on how these are plumbed and routed use Radium part number 20-0484-08.

OPTIONAL ACCESSORIES

FUEL LEVEL SENDER
The FCST comes standard with a fuel level sender block off plate. However, SAE fuel level senders of various lengths can be purchased separately Radium part number 20-0747-203.

FUEL LEVEL SWITCH / DIAGNOSTIC INDICATOR
These new FCSTs come standard with a 2AN ORB plug preinstalled in the "level switch" port. This little device provides a warning when the fuel level inside surge tank canister drops by 20% or more.

• Universal