Radium Engineering FCST Fuel Cell Surge Tank - External Pumps (No Pumps Included)
Part Number: 20-0695-00
Note: 10 and 14 Gallon fuel cells will require the Lift Pump Extension Bracket (20-0214).
Background
Since 2010, Radium Engineering external fuel surge tanks have been the benchmark solution for eliminating fuel starvation in motorsport. In 2013, Radium introduced the first-generation Fuel Cell Surge Tank (FCST) — a drop-in system that quickly became the preferred fuel setup for professional racing teams worldwide.
What Is the FCST?
The FCST is a complete drop-in fuel pump system designed for Radium Engineering fuel cells or any cell using the industry-standard 6×10, 24-bolt fill plate bolt pattern. Unlike a basic trap door or baffle box, the FCST features a true dual-chamber fuel tank with a single lift pump and up to three surge tank pumps — all packaged inside the fuel cell. It delivers all the benefits of a traditional external surge tank without the plumbing complexity or safety concerns.
The 20-0695-00 variant is supplied without pumps and is designed for use with a mechanical fuel pump or inline electric pump(s). One or two -10AN (5/8") fuel pickups are used inside the surge tank, each fitted with an 80-micron filter. If two pickups are used, the 20-0737 Distribution Block is recommended for pumps with a 12AN inlet.
Compatibility Requirements
To install the FCST into a fuel cell, the following criteria must be met:
- Cell must have the industry-standard 6"×10" 24-bolt flange opening
- Opening must be on the top face of the fuel cell (not a side face)
- Cell depth must be at least 7.7" (196mm) measured from the outer top face to the internal bottom face
Standard Fittings
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PUMP OUT - -8AN Male: External pump outlet port (engraved "PUMP OUT"). Uses 7/8"-14 threads, compatible with all 10AN ORB fittings. Supplied with a 10AN ORB to 8AN male adapter. Additional 10AN ORB adapters available separately.
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RETURN - -6AN Male: External return port for low-pressure fuel from the FPR. Uses 3/4"-16 threads, compatible with all 8AN ORB fittings. Supplied with an 8AN ORB to 6AN male adapter. Additional 8AN ORB adapters available separately.
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VENT - -8AN Male: External vent port tapped with 1-1/16"-12 threads, compatible with all 12AN ORB fittings. Supplied with 20-0435 (8AN male outlet). For quick-fill dry break systems, 20-0535 (12AN male) is available separately.
What Else Is Needed?
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Fuel Cell: Not included. Must use a 6×10, 24-bolt fill plate flange with a minimum internal depth of 7.7" (196mm). For cells deeper than 10", the Lift Pump Extension (20-0214) is required.
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Fuel Filler: If a 6-bolt (2.18" B.C.) filler is not already fitted, Radium Engineering offers options for both direct and remote filling.
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Vent Hose: A hose and/or filter must be connected to the VENT port fitting.
Optional Accessories
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Fuel Level Sender: Supplied with a block-off plate as standard. SAE fuel level senders of various lengths are available separately.
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Fuel Level Switch / Diagnostic Indicator: Supplied with a 2AN ORB plug in the level switch port. This device provides a warning when the surge tank fuel level drops by 20% or more.
Why Radium Engineering?
- ✅ Manufactured in the USA to motorsport-grade tolerances
- ✅ CNC-machined billet aluminium components for maximum durability and precision
- ✅ Trusted by professional tuners and race teams running high-power EFI builds worldwide
- ✅ Bolt-on fitment — no cutting, drilling, or custom fabrication required
- ✅ Compatible with E85, pump petrol, and flex fuel sensor integration for versatile fuel system builds
