Fastest easiest way to convert fuel system to AN/O-ring

Asco's fuel rails have 1/4npt ports and is supplied with -6an fittings, used with a regulator like aem or fuelab that also provides ports with -6 fittings, you can keep everything -an… then pickup 1/4npt barb fitting to mate to the return hose

I'm wondering if your fuel filter may be clogged or collapsing from trying to keep up? A good barb fitting with appropriate clamps should not leak, perhaps try higher pressure rated r10 (submersible) hose? Something around 300psi, with mini t-bolt mikalor clamps?

^ what he said, are you using z31 fuel filter? and fuel injection type fuel hoses? can try using gf z32 filter, it supposedly flows better, And I Found really good injector type hose on eBay… rated around 125 psi. was cheap for 25 ft of it

Thanks for the lead. They are quality high pressure lines and quality clamps, I think it's just beyond what these components were designed for. also, OEM fuel rails w/MB 036's.

Good point about the fuel filter, i suppose a mesh screen type would perform under such conditions.

I'm planning to go full AN feed and return which makes a bit more work than a cut and clamp.


Question about the injectors though.
If i go O-ring style, it would seem the MB 036's would be ditched. Any info on steps to prepping the LIM for O-ring style? Links to other discussions? From what i can find it just involves reaming out the injector ports.

As I said zach sells top-feed 11mm o-ring rails, I got some (and anodized them with my other parts), you could use them directly unless yours were too tall for some reason, but then spacers or new hold down brackets would solve that too

If on the other hand your injector tips (nozzle side) are also o-ring, then it's still possible you could get the normal pintle caps from a repair kit, and just hog out the end with a drill so it becomes more of a sleeve, then slide the standard seat seal over that

Try using 30R10 hose before abandoning your clamps

I'm currently doing failure testing on Federal/Gates silicone hose here at work and have hydrostatic pressure tested 3/8 ID silicone hose using single ABA SS bolt-style mini clamps (similar to mikalor) and beaded (not barbed) 3/8" tubing and have repeatably held pressures ~400PSI (the hose is rated to 250). The only premature leaking I've encountered has been with barbed fittings, bolt style clamps that were being used beyond their limited range and beaded fittings that were not clean of forming oils. Not that silicone hose is applicable here but, surface prep does make a difference.

interesting stuff, it was a last minute job. I've reset them before only to have leaks come back. I'll take that into consideration and try some higher quality hose, prepping the surfaces correctly, and make the switch to better clamps before dropping the cash on an AN system

Note: leaks were on the high pressure side of the fuel rail feed lines from an aeromotive 13101-A1000 FPR. and the firewall side junction. All are double clamped.

FPR is manifold pressure regulated, base at 60PSI vac at -13Hg/", final tune it will see +18 PSI, so 78 PSI intermittent.

All the fuel hoses I used in my system, around the injectors is 300psi rated, with the anti-scuff dual braided 2500psi hose to and from the filter up to the rail....

Everything small diameter clamp in the engine bay is either mikalor t-bolts or ipex crimps