Radium FCST-X, Fuel Cell Surge Tank

To configure a complete fuel cell with FCST-X and other accessories, click here.

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, Radium Engineering introduced the first to market Fuel Cell Surge Tank (FCST) in 2013. The current generation of the FCST is still a great cost efficient solution and are found HERE. This FCST quickly became the preferred fuel system for the competition vehicle market and professional racing. After 10 years of kaizen, the transformation brings the release of the FCST-X (Fuel Cell Surge Tank-10 Years).

FCST-X FEATURES

LEGACY FCST FEATURES
The features listed below carry over from previous fuel cell surge tanks.
-Merged single 10AN ORB female threaded outlet. All pumps use check valves that prevent back-flow.
-One-way fill valves (355LPH each) 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 eliminates 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.
-Optional fuel surge tank level switch and diagnostic LED failsafe port.
-Rollover vent valve protection 

NEW FEATURES
In addition to all previous FCST features, the new FCST-X rendition is packed with innovations.
-Fast lift and surge pump access (9 bolts total)
-Integrated lift handle for fuel pump servicing
-Lightweight surge tank increased from 2.2L to 2.6L
-Compatible with up to 4 brushless fuel pumps
-Up to 4 Bosch BR540 fuel pumps (DW400) 
-Up to 3 Ti Automotive E5LM brushless pumps
-Up to 4 brushless Bosch pumps (DW440)
-Compatible with 16AN inlet mechanical pumps
-Easily swappable pump modules (sold separately)
-Compatible with shrouded level sensors
-Designed with less potential leak points
-Improved fluid control for quick filling
-Optimized internal fluid management
-Enhanced roll over protection
-Anti-rotation electrical terminals

COMPATIBLE WITH MY FUEL CELL?
To install a Radium Engineering FCST-X into a fuel cell, the following criteria must be met:
1. The fuel 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. As shown below, fuel cannot pass between the 3 independent filtration chambers (A, B, C). If less than 3 pumps are installed, the empty port does NOT need to blocked off.

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 fuel 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.

STANDARD FITTINGS

PUMP OUT, 8AN MALE
The 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-X comes standard with a common 10AN ORB to 8AN male adapter fitting. However, various 10AN ORB adapter fittings can be purchased separately HERE.
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-X comes standard with a common 8AN ORB to 6AN male adapter fitting. However, various 8AN ORB adapter fittings can be purchased separately HERE. 
VENT, 8AN MALE
The "VENT" port is tapped with 1-1/16"-12 threads making it compatible with all 12AN ORB fittings. The FCST-X comes standard with 20-0934 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-X variation
-Anodized aluminum 6x10 plate
-Anodized aluminum surge tank pump hat
-Anodized aluminum lift pump hat
-Anodized aluminum service handle
-Anodized aluminum level sensor plate
-Anodized aluminum surge pump bracket
-Stainless lift pump mounts (shallow and deep)
-Lift pump and surge pump fuel filters
-Anodized aluminum 8AN roll over vent valve
-FKM refueling rollover protection seal
-FKM 6x10 24-hole sealing gasket
-8AN ORB to 6AN male return fitting
-10AN ORB to 8AN male pump out fitting
-2AN ORB fuel level switch plug
-FKM 1-way fill valves (x3)
-Anodized aluminum acorn nuts
-Electrical wire ring terminals

Links for compatible fillers (not included), Direct Mount or Remote Mount

SELECTING YOUR FCST-X
The different FCST-X part numbers are based on the brand and quantity of fuel pumps. When determining a fuel pump configuration, select a combination that can support the engine output. The lift pump is always matched to be the same style pump(s) found inside the fuel surge tank, with exception to the 20-1993-00 brushless Ti Automotive E5LM variation.

A FCST-X that states "pump included" comes pre-assembled with new fuel pumps and filters installed.

For a FCST-X that states "pumps not included", fuel pumps must be sourced separately. A filter sock is only used for the lift pump as inlet filters are already supplied for the surge tank pumps. Also, there will be enough components included with this option to use up to 3 pumps in the surge tank. More fuel pump information can be found HERE.

20-1990-00
This FCST-X does not include fuel pumps. It can hold up to 3 surge tank pumps and 1 lift pump of the following.

PUMP COMPATIBILITY
- Walbro GSS342
- AEM 50-1200
- *Deatschwerks DW440
*Use the electrical connector provided with the pumps.

20-1990-01
This FCST-X is preassembled with 1 Walbro GSS342 lift pump and 1 Walbro GSS342 surge tank pump.

20-1990-02
This FCST-X is preassembled with 1 Walbro GSS342 lift pump and 2 Walbro GSS342 surge tank pumps.

20-1990-03
This FCST-X is preassembled with 1 Walbro GSS342 lift pump and 3 Walbro GSS342 surge tank pumps.

20-1991-00
This FCST-X does not include fuel pumps. It can hold up to 3 surge tank pumps and 1 lift pump of the following.

PUMP COMPATIBILITY
- **Bosch BR540
- *Deatschwerks DW400
*Use the electrical connector provided with the pumps. For the lift pump, use the filter sock provided with the pump.
**Because this pump does not include a built-in check valve, multiple surge pumps must be ran together (not staged).

20-1992-00
This FCST-X does not include fuel pumps. It can hold up to 3 surge tank pumps and 1 lift pump of the following.

PUMP COMPATIBILITY
- Walbro F90000267
- Walbro F90000274
- Walbro F90000285
- *Walbro F90000295
*Because this pump does not include a built-in check valve, multiple surge pumps must be ran together (not staged).

20-1992-01
This FCST-X is preassembled with 1 Walbro F90000274 lift pump and 1 Walbro F90000274 surge tank pump.

20-1992-02
This FCST-X is preassembled with 1 Walbro F90000274 lift pump and 2 Walbro F90000274 surge tank pumps.

20-1992-03
This FCST-X is preassembled with 1 Walbro F90000274 lift pump and 3 Walbro F90000274 surge tank pumps.

20-1993-00
This FCST-X does not include fuel pumps. It can hold up to 2 surge tank pumps and 1 lift pump of the following.

SURGE PUMP COMPATIBILITY
- *Ti Automotive E5LM (check valves included)

LIFT PUMP COMPATIBILITY
- *Ti Automotive E5LM
- **Walbro F90000267
- **Walbro F90000274
- **Walbro F90000285
- **Walbro F90000295
*This pump requires a brushless controller. These typically come standard when purchasing the pump. See Ti Automotive BKS1001.
**For these pumps, it is recommended to use the Radium Engineering 14-0143 filter sock.

20-1995-00
There are two 80u (micron) filters included for two 10AN (5/8") pickups. If using the provided 16AN (1") pickup, an external filter will need to be purchased.
The surge tank can be configured to use any combination of the following: 

SURGE TANK COMPATIBILITY
- (1x) 10AN pickup (shown below) for an inline external pump or mechanical pump.

- *(2x) 10AN pickups for an inline external pump and/or mechanical pump.
- (1x) 16AN pickup for an inline external pump or mechanical pump.
- *(1x) 16AN pickup and (1x) 10AN pickup (shown below) for an inline external pump and/or mechanical pump.

*An electric pump can be used to prime a mechanical pump (for faster engine starting) when running 2 of the pickups.
This FCST-X does not include a fuel pump for the lift pump. It is compatible with the following.

LIFT PUMP COMPATIBILITY
- Walbro F90000267
- Walbro F90000274
- Walbro F90000285
- Walbro F90000295

WHAT ELSE IS NEEDED?

FUEL CELL
A fuel cell is NOT included with the FCST-X. 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 9" (229mm), click HERE.

FUEL FILLER
The FCST-X fuel filler pattern uses a 3-bolt (59.5mm P.C.D.) flange. Radium Engineering has them for both direct filling and remote filling.

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, go HERE.

OPTIONAL ACCESSORIES

SPARE DROP-IN PUMP MODULES
An FCST-X spare drop-in pump module is an additional lift and surge pump assembly for super fast pit stops. If fuel pressure issues arise, 9 bolts out and back in will get your team back on the track. Pumps are not included.

Radium P/N: 20-1996 is shown below.

PUMP COMPATIBILITY
- Walbro GSS342
- AEM 50-1200
- *Deatschwerks DW440
*Use the electrical connector provided with the pumps.

Radium P/N: 20-1997 is shown below.

PUMP COMPATIBILITY
- **Bosch BR540
- *Deatschwerks DW400
*Use the electrical connector provided with the pumps. For the lift pump, use the filter sock provided with the pump.
**Because this pump does not include a built-in check valve, multiple surge pumps must be ran together (not staged).

Radium P/N: 20-1998 is shown below.

PUMP COMPATIBILITY
- Walbro F90000267
- Walbro F90000274
- Walbro F90000285
- *Walbro F90000295
*Because this pump does not include a built-in check valve, multiple surge pumps must be ran together (not staged).

Radium P/N: 20-1999 is shown below.

SURGE PUMP COMPATIBILITY
- *Ti Automotive E5LM (check valves included)

LIFT PUMP COMPATIBILITY
- *Ti Automotive E5LM
- **Walbro F90000267
- **Walbro F90000274
- **Walbro F90000285
- **Walbro F90000295
*This pump requires a brushless controller. These typically come standard when purchasing the pump. See Ti Automotive BKS1001.
**For these pumps, it is recommended to use the Radium Engineering 14-0143 filter sock.

FUEL LEVEL SENDER
The FCST-X comes standard with a fuel level sender block-off plate. However, SAE fuel level sensors of various lengths can be purchased separately HERE.

FUEL LEVEL SWITCH / DIAGNOSTIC INDICATOR
The FCST-X comes standard with a 2AN ORB plug preinstalled in the "level switch" port. For information on adding a fuel level switch and diagnostic indicator, click HERE. This little device provides a warning when the fuel level inside surge tank canister drops by 20% or more.