Radium Engineering -8AN ORB Port Plug | Fuel & Oil System Blanking Fitting

The Radium Engineering -8AN ORB Port Plug is a precision-machined blanking fitting designed to seal unused -8AN O-ring boss (ORB) ports in high-performance fuel, oil, and coolant systems — providing a clean, leak-free closure on any -8AN ORB port that is not in active use in the plumbing circuit. Whether you're capping an unused fuel rail port, blocking an oil cooler inlet during a system reconfiguration, or sealing an engine block ORB port that is not required for your specific build, this plug delivers the same precision machining and sealing reliability as Radium Engineering's full fitting lineup. A small but essential component for any builder who demands a clean, professional finish on every port in their fuel or oil system.

Key Features:

• -8AN ORB thread — 3/4–16 UNF thread form matches the -8AN O-ring boss (ORB) port standard used on fuel rails, oil coolers, engine block ports, and other high-performance plumbing components
• O-ring boss sealing — seals via O-ring compression at the port face for a positive, leak-free closure that is superior to tapered thread plugs in high-pressure fuel and oil applications
• Precision-machined construction — machined to Radium Engineering's quality standards for accurate thread form and correct O-ring seating surface geometry
• Clean port closure — provides a professional, finished appearance on unused ORB ports — no exposed open ports or improvised plugs in the plumbing system
• Radium Engineering quality — manufactured by one of the most respected names in high-performance fuel system components for import and domestic performance platforms

Technical Details:

• Port Size: -8AN O-ring boss (ORB)
• Thread: 3/4–16 UNF
• Seal Type: O-ring boss (ORB) — seals via O-ring compression at port face
• Function: Blanking plug — seals unused -8AN ORB ports
• Suitable Applications: Fuel, oil, and coolant system ORB ports

Specifications:

• Brand: Radium Engineering
• Part Number: RAD14-0150
• Port Size: -8AN ORB
• Thread: 3/4–16 UNF
• Construction: Precision-machined
• Application: Blanking / sealing unused -8AN ORB ports in fuel, oil, and coolant systems

Compatibility & Use Cases:

• Sealing unused ports on aftermarket and OEM fuel rails with -8AN ORB port outlets
• Blocking unused inlets or outlets on oil coolers, oil filter adapters, and oil sandwich plates with -8AN ORB ports
• Capping unused -8AN ORB ports on engine blocks, cylinder heads, or other engine components
• Sealing ports on Radium Engineering fuel surge tanks, fuel rails, or other Radium components during system configuration
• Note: Verify O-ring material compatibility with your specific fluid (fuel, oil, or coolant) before installation. Replace the O-ring if reusing the plug after removal. Use a quality AN-compatible O-ring rated for your fluid type.

What's Included:

• Radium Engineering -8AN ORB port plug — RAD14-0150 (1 piece)
• O-ring (verify inclusion with product — replace O-ring if reusing after removal)

Installation Notes:

• Apply a light film of clean oil or assembly lubricant to the O-ring before installation to prevent pinching and ensure correct seating at the port face
• Thread the plug into the ORB port by hand until the O-ring contacts the port face, then tighten to the manufacturer's specified torque — do not overtighten, as this can damage the O-ring and port face seating surface
• Inspect the O-ring for damage or deformation before installation and replace if necessary
• Pressure-test the completed system before returning to full-load operation — verify the plug is leak-free at operating pressure
• Inspect the O-ring at each service interval and replace as needed

Why Use a Quality ORB Plug?

Unused ports in a high-performance fuel or oil system are a potential leak point if not properly sealed — and improvised solutions like generic pipe plugs or tapered thread fittings in an ORB port are a common source of fuel and oil leaks in custom builds. O-ring boss (ORB) ports are designed to seal via O-ring compression at the port face, not via thread interference — which means a tapered NPT plug threaded into an ORB port will not seal correctly and risks damaging the port's seating surface. Radium Engineering's precision-machined ORB plug provides the correct thread form and O-ring seating surface geometry for a reliable, leak-free seal in any -8AN ORB port — the right solution for a system that needs to be built correctly the first time.

Why Radium Engineering?

Radium Engineering is one of the most respected names in high-performance fuel system engineering — with a product lineup spanning fuel surge tanks, fuel rails, fuel pressure regulators, catch cans, and the full range of fittings, adapters, and hardware needed to build a complete, reliable high-performance fuel system. Radium's engineering philosophy emphasizes precision manufacturing, correct material selection, and system-level thinking — their fittings and plugs are purpose-engineered components manufactured to the tolerances and material specifications that high-performance fuel and oil systems demand. For builders who want every component in their system to meet the same standard as the major components, Radium Engineering hardware is the correct choice.

Perfect For:

• Sealing unused ports on aftermarket fuel rails during fuel system builds or reconfigurations
• Blocking unused oil cooler or oil filter adapter ports in custom oil cooling circuits
• Capping unused engine block or head ORB ports in engine swap or custom plumbing builds
• Any high-performance fuel or oil system build where unused -8AN ORB ports need to be sealed cleanly and reliably

Pro Tip: Keep a selection of ORB plugs in common AN sizes (-6AN, -8AN, -10AN) in your build hardware kit — unused ports are a frequent occurrence in custom fuel and oil system builds, and having the correct plug on hand avoids delays and improvised solutions that compromise system integrity. Pair with Radium Engineering's full fitting and adapter lineup for a consistent, precision-machined hardware standard throughout your plumbing system.

Note: Verify O-ring material compatibility with your specific fluid before installation. Replace the O-ring if reusing the plug after removal. Pressure-test all connections before returning to full-load operation.