EVIL ENERGY 6AN to 3/8" Quick-Disconnect Fuel Rail Adapter — 2pc Aluminum 6061-T6, 1500 PSI

EVIL ENERGY 6AN male to 3/8" quick-disconnect female EFI fuel rail fitting is an aluminum, high-pressure adapter that turns a 6AN threaded feed into a 3/8" quick-disconnect line for EFI rails and fuel-system components.

This pair of fittings is engineered for fuel-system work on performance and retrofit projects. Machined from 6061-T6 aluminum and sealing at a 37° flare, these adapters are built to handle high pressure while minimizing leaks. They’re commonly used where a bulkhead or fuel rail needs a convenient quick-disconnect connection to sensors, return lines, or aftermarket hoses during engine swaps and service routines.

How do these fittings prevent leaks in a high-pressure EFI system?

The fittings use a 37° flare sealing geometry that matches industry-standard AN flare practice, producing a reliable metal-to-metal seal when torqued correctly. The precision threads and flare face reduce the chance of seepage under repeated cycling.

• 37° flare angle for a tight metal-to-metal seal
• 9/16-18UNF 6AN thread sizing for proper mating
• 6061-T6 aluminum resists corrosion while maintaining dimensional stability
• Rated to 1500 psi to suit many EFI applications

Will these adapters fit my existing 6AN fuel rail and 3/8" quick-disconnect hose?

Yes, these adapters are sized to convert a standard 6AN male thread (9/16-18UNF) to a 3/8" quick-disconnect female interface. Confirm that your hose or quick-disconnect coupling is the standard 3/8" type used in fuel systems to ensure compatibility.

• Thread: 6AN (9/16-18UNF) male
• Quick-disconnect inner diameter: 3/8" female
• Intended for EFI rails, sensors, cooler lines, and return plumbing
• Sold in a 2-piece set for matching both inlet and outlet needs

What operating conditions and materials are these fittings rated for?

Manufactured from aircraft-grade 6061-T6 aluminum, the adapters combine light weight with strong mechanical properties. They are tested for automotive fuel-service ranges and can tolerate typical engine-bay temperatures and pressures when installed correctly.

• Material: 6061-T6 aluminum alloy for strength and corrosion resistance
• Working pressure rating: up to 1500 psi under correct installation
• Temperature range: -40°F to 250°F suitable for most engine compartments
• Flare-sealed design avoids rubber seals that can degrade in fuel contact

How should I install and maintain these fuel rail fittings?

Install by matching the 6AN threads to the fuel rail or adapter and tighten to the manufacturer’s recommended torque for AN fittings to avoid thread or flare damage. Periodic inspection for tightness and any signs of abrasion or fuel odor is a simple preventive step.

• Hand-start threads, then torque to AN specifications to avoid over-tightening
• Inspect the 37° flare face for nicks or debris before final assembly
• Check fittings after initial run-in and periodically for seepage or looseness
• Replace if threads or flare faces become damaged

Who is this for? These EVIL ENERGY adapters are aimed at mechanics, DIY tuners, and performance enthusiasts performing EFI conversions, LS swaps, or custom fuel-system plumbing. If you need a compact, reusable transition from a 6AN threaded port to a 3/8" quick-disconnect line for sensors, return plumbing, or service access—especially in high-pressure environments—this 2-pack provides a durable, serviceable solution.