EVIL ENERGY AN8 ORB Block-Off Cap Set — 3/4-16 UNF Aluminum Hex Plugs, O-Ring Sealed (2-Pack)

EVIL ENERGY's AN8 ORB block-off cap is a pair of milled 6061-T6 aluminum male adapters that seal AN8/3/4-16 UNF ports with an O-ring for reliable, high-pressure service.

These machined aluminum ORB plugs are designed to close off AN8-sized openings on fuel lines, rails, regulators and cooling components where a secure, reusable seal is needed. The kit includes two precision-threaded caps that mate with 3/4-16 UNF hex ports, an elastomer O-ring for sealing, and a corrosion-resistant finish suitable for performance and maintenance tasks. Built to operate across a wide temperature range and rated for substantial system pressures, they simplify maintenance and modifications without requiring permanent fittings or welding.

How do these ORB block-off caps seal and stay leak-free?

The caps use an elastomer O-ring seated in the face of the plug to create an ORB (O-ring boss) seal against the mating surface. When torqued to specification, the O-ring compresses and forms a fluid-tight barrier without damaging threads.

• Face-sealing O-ring design for repeatable, non-thread-sealing closure
• NBR elastomer selected for chemical resistance in fuel and oil systems
• Hex body allows controlled torque with standard wrenches
• Designed to be removable for rework or inspection

What thread and size compatibility should I expect?

Each cap features AN8 hex threads specified as 3/4-16 UNF, the common sizing for AN8 male fittings. Confirm port type as ORB/O-ring boss or AN8-style threading before installation to ensure correct fit.

• Thread specification: 3/4-16 UNF (AN8 standard)
• Hex shape accommodates common wrenches for tightening and removal
• Intended for ORB ports or equivalent hex boss ports on rails and housings
• Sold as a set of two caps for paired applications or spares

What operating conditions and materials are these plugs rated for?

Manufactured from 6061-T6 aluminum for a balance of strength and light weight, the plugs accept an NBR O-ring and are specified for use in high-pressure non-hydraulic applications such as fuel systems. They are rated for substantial pressure and a broad temperature envelope suitable for automotive and motorsport service environments.

• Material: 6061-T6 aluminum body with NBR (nitrile) O-ring
• Working pressure rating up to approximately 1500 psi
• Operating temperature range from about -65°F to 252°F; O-ring tolerance listed 122°F–140°F
• Corrosion-resistant finish for durability in engine bays and exposed locations

Where are these block-off plugs typically used and how are they installed?

These plugs are commonly used to cap spare ports on fuel rails, pressure regulators, cooling components, and other AN8/ORB-compatible fittings during assembly or when ports are not needed. Installation is straightforward: clean the port face, place the O-ring, thread the plug hand-tight, then finish with a wrench to the recommended torque.

• Common applications: fuel rails, fuel pressure regulators, coolant housings and manifold ports
• Installation: hand-start threads, then wrench-tighten using the hex flats—do not over-torque
• Reusable: remove and re-install without thread damage when serviced properly
• Sold as a two-piece set for convenience during works or as backups

Who is this for: Technicians, tuners, and DIY enthusiasts who work on performance fuel or cooling systems and need a dependable, removable way to seal AN8/3/4-16 ORB ports. The EVIL ENERGY caps are suited for shop repairs, vehicle builds, track-day prep, and maintenance tasks where a lightweight, corrosion-resistant plug with a reliable O-ring seal is preferred over permanent closures.