Fluid Adapter Fittings

Every fluid system on a built car comes down to the joints, and this is where Radiant Speed Works keeps the Vibrant Performance adapter fittings that tie AN hose, hard line and factory ports together. You will find straight, 45 and 90 degree adapters, AN to NPT, ORB and metric transitions, banjo bolts and fittings, bulkheads, unions, reducers, plugs and barbs in sizes from -3AN through -20AN.

Match the thread before you match the size

Most fitting problems start with a thread mix-up. AN (Army-Navy) fittings seal on a 37 degree flare, so the male and female cones do the sealing and the threads only hold them together. NPT is a tapered pipe thread that seals on the threads themselves and needs a sealant rated for the fluid. ORB, or O-ring boss, uses a straight thread with an O-ring at the base, and it is what you will find on many pumps, filter housings and modern engine blocks. Metric adapters cover the factory ports on imported engines and transmissions, and they usually seal with a crush washer. If you know which thread a port has, choosing the right adapter is simple: one end matches the port, the other matches your line.

Banjo fittings and bolts

Banjo fittings let a line leave a port at a right angle in tight spaces, which is why they show up on turbo oil feeds, brake calipers, fuel rails and carburetors. Vibrant lists them in imperial and metric bolt sizes, single and dual, with male AN outlets so they drop straight into an AN plumbing job. Always use fresh crush washers on each side of the banjo and torque the bolt to spec. A reused washer is the most common cause of a weeping banjo joint.

Bulkheads, unions and reducers

Bulkhead fittings pass a line cleanly through a firewall, fuel cell or trunk floor and lock down with a jam nut, with PTFE washers available to seal against the panel. Unions join two AN lines without a hose end, and reducers and expanders step a line up or down a size when a pump outlet and a rail inlet do not match. Plugs and caps close off unused ports so you can run a system without leaks.

Material and finish

The bulk of this line is machined aluminum with an anodized finish, which keeps weight down and resists corrosion around fuel, oil and coolant. Brass olive inserts and barbed adapters cover hard line and push-on hose, and stainless pieces are offered where heat or chemical exposure calls for them.

Common questions

Can I connect AN fittings to NPT ports? Yes. That is what an AN to NPT adapter does. The NPT side seals on the tapered thread with sealant, and the AN side seals on the 37 degree flare with no sealant on the cone.

What does the dash size mean? The dash number is the outside diameter of the matching tube in sixteenths of an inch, so -6AN matches 3/8 inch tubing and -8AN matches 1/2 inch.

Do these fittings work with E85 and race fuel? The anodized aluminum fittings are commonly used with gasoline, E85 and methanol. Pair them with a hose that is rated for the fuel you run, because the hose liner is usually the deciding factor.