EVIL ENERGY AN Female to AN Male Flare Fitting Y Block Union Splitter Swivel Adapter Fitting Aluminum Black

Q: What does the female swivel end of the EVIL ENERGY AN female to dual male Y adapter thread onto?
A: The female swivel inlet threads onto any male 37° AN or JIC flare of the same dash size: a male AN outlet on a fuel pump, a fuel filter end, a male AN fitting on a fuel rail, or an ORB-to-AN adapter in an engine block or oil filter housing. A 6AN female inlet needs a 6AN male (9/16-18) port, a 10AN female needs a 10AN male (7/8-14) port, and so on. It will not seal on a 45° SAE flare, and it cannot thread into an NPT pipe port directly; for NPT, install a male NPT to AN adapter first and mount the Y adapter on that.

Q: Can the AN female to dual male Y adapter run backwards to merge two lines into one?
A: Yes. Y adapters have no flow direction, so the two male ports can act as inlets and the female swivel as the outlet. The common example is two fuel pumps feeding one supply line. Size matters more in this direction: the single female port has to carry the combined flow of both branches, so for dual pumps choose the 10AN female to 2 × 8AN male version, never the 6AN female to 2 × 8AN male, which would bottleneck both pumps.

Q: Which size AN female Y adapter splits an oil feed for twin turbochargers?
A: The 6AN female to 2 × 4AN male version is the usual choice. It mounts on a -6 male oil feed fitting at the block or filter housing and sends a -4 line to each turbo. Journal-bearing turbos commonly run -4 feed lines; ball-bearing turbos often need a restrictor in each feed line, sized to the turbo maker's spec, so check that before the first start.

Q: Why does the 6AN female to 2 × 8AN male Y adapter have outlets larger than the inlet?
A: The 6AN female to 2 × 8AN male Y adapter is for builds where the two components downstream already use -8 hose ends, such as an oil cooler and a filter relocation block, but the source port is -6. It saves two reducer fittings. The trade-off is that both branches together can never flow more than the -6 inlet, so it fits low-to-moderate flow circuits, not a main fuel feed on a high-horsepower engine.

Q: Do I need Teflon tape or thread sealant on the 37° flare of the AN Y block swivel adapter?
A: No. The AN Y block swivel adapter seals metal to metal at the 37° flare cone, and tape or paste on the cone can hold the faces apart and cause the very leak you are trying to stop. Shredded tape in a fuel line also ends up in filters and injectors. A light drop of engine oil on the threads only, not the cone, is all the joint needs.

Q: How tight should the swivel nut on the aluminum AN Y adapter be?
A: Run the swivel nut down by hand until the flare seats make contact, then tighten roughly another 1/8 to 1/4 turn while holding the Y body with a second wrench so it does not twist. Aluminum flares deform if you lean on them like steel hydraulic fittings, and a crushed cone leaks no matter how much you tighten afterward. An aluminum AN wrench protects the anodized nut from tool marks. If a joint seeps after pressurizing, back it off, inspect the cone and re-seat it rather than cranking harder.

Q: Is the black anodized aluminum AN female Y adapter safe to use with E85?
A: Yes. E85 is listed in the compatible media for this AN female Y adapter, and anodized 6061 aluminum is the standard material for E85 fuel fittings. With ethanol blends the hose is the weak point more often than the fitting, which is why most E85 builds pair aluminum AN fittings with PTFE fuel line kits. Check the anodized surfaces for white residue during routine service if the car sits for long stretches on E85.

Q: What hose ends connect to the two male outlets of the AN female to dual male Y adapter?
A: Each male outlet takes a female AN hose end in the same dash size, straight or angled, from any brand that uses the 37° AN flare. A 3×8AN Y adapter needs two -8 female hose ends; a 10AN female to 2 × 8AN male version also needs two -8 female hose ends on the outlet side. Match the hose end to the hose type: rubber or CPE hose and PTFE-lined hose use different hose end designs.

Q: Why is the swivel side of the AN Y adapter weeping fuel after installation?
A: A weep at the swivel end of an AN Y adapter almost always traces back to one of four causes. The mating fitting is a 45° flare rather than 37°. The male cone has a nick or a burr. The nut was started cross-threaded. Or the flare was overtightened and flattened. Depressurize the line, remove the Y adapter and look at both cones under good light; a ring of uneven contact or a visible scratch across the seat shows which side is at fault.

Q: Should I buy the AN female swivel Y adapter or an all-male AN Y block?
A: Choose the AN female swivel Y adapter when one side of the split bolts straight onto a male AN port on a pump, filter, rail or ORB adapter; it removes a union and one potential leak point. Choose an all-male AN Y block when hoses come in and go out on all three sides, or when you need -3 or -12 sizes. Both styles are in the AN Y fittings collection.