EVIL ENERGY 6AN to 3/8in & 5/16in Quick-Disconnect Fuel Adapter — 37° Flare Aluminium, 1500 PSI

EVIL ENERGY's 6AN male to 3/8" & 5/16" quick-disconnect female fuel fitting is a compact aluminum adapter engineered to join a 6AN threaded line to either 3/8" or 5/16" quick-disconnect fuel connectors with a 37° flare seal.

This fitting converts a 6AN (9/16-18UNF) male threaded feed into a dual-ID quick-disconnect female interface, letting you connect common fuel hoses or sensors without custom fabrication. Built from 6061-T6 aluminum with a plastic spring lock and a 37° flare sealing surface, it balances corrosion resistance, light weight, and a high working pressure rating suitable for many performance and maintenance applications.

How does this adapter ensure a leak-resistant connection?

The adapter relies on a 37° flare sealing geometry that compresses against the mating flare to form a metal-to-metal seal, minimizing reliance on soft seals. A plastic-encapsulated spring lock secures the quick-disconnect female halves, keeping connections engaged under vibration.

• 37° flare angle for a proven pressure seal
• Metal-to-metal contact reduces soft-seal failure points
• Plastic spring lock prevents accidental disconnection
• Precision 9/16-18UNF thread for tight engagement

What temperature and pressure limits can I expect in real use?

This fitting is rated to operate up to 1500 psi and across a broad temperature range from -40°F to 250°F, covering most automotive fuel delivery and return systems. Those limits make it suitable for typical EFI and mechanical fuel setups, though extreme racing or specialty fluids may need higher-rated components.

• Working pressure: 1500 psi
• Operating temperature: -40°F to 250°F
• Suitable for gasoline and many blended fuels used in automotive systems
• Not intended for applications beyond specified temperature/pressure ratings

Which materials are used and why does that matter?

The body is machined from 6061-T6 aluminum, a common choice for strength, corrosion resistance, and lightness in automotive fittings. The spring lock uses a durable plastic to reduce galling on mating parts while still providing reliable locking action.

• 6061-T6 aluminum: durable and corrosion-resistant
• Plastic spring lock: prevents metal-on-metal wear
• Precision machining ensures consistent thread and flare geometry
• Lightweight for race and street builds where mass matters

What installations or systems is this adapter used with?

It’s commonly used where a 6AN line must interface with smaller quick-disconnect fuel fittings—ideal for fuel rails, LS swaps, return lines, transmission coolers, and inline sensors. The dual-ID female design lets installers choose between 3/8" and 5/16" hose IDs without separate adapters.

• Fuel rails and EFI return lines
• LS engine swaps and aftermarket fuel systems
• Transmission cooler feed/return when using compatible fittings
• Fuel sensors and inline diagnostic ports

Who is this for: Technicians, tuners, and DIY enthusiasts who need a compact, reliable way to adapt a 6AN male connection to standard quick-disconnect female fuel lines. If you require a lightweight, corrosion-resistant adapter rated for typical EFI pressures and temperatures, this EVIL ENERGY fitting offers a straightforward solution for repairs, swaps, or custom plumbing without fabricating custom hose ends.