PDA

View Full Version : AN line life expectancy?



another69
04-20-2008, 04:06 PM
Call me a worrier, but I just read an article in a car mag and mentioned that braided steel AN line is only good for "a few" years if used with pump gas, unless it's teflon lined. That's a good chunk of change every few years.
I normally use Aeroquip line, and the oldest stuff I've got has been full of pump gas for 7 years now, and I've yet to see any hose debris in my carb or filters.
I'm not about to run unprotected rubber line for my fuel lines, and hard tubing is not always practical. I know alot of you out there use this stuff- any problems over time?

CarlC
04-20-2008, 06:25 PM
The cost differance between stainless braid over rubber vs. stainless braid over teflon is minimal. The teflon fittings flow better than comparable standard AN fittings, and the hose will likely outlast the car. The standard AN fittings have more WOW factor, but don't work as well and are more difficult to assemble than teflon.

I'm running hardline for most of the runs with teflon flex lines on each end.

Many find that stainless braid over rubber hoses permeate fuel vapors. Like any rubber product, periodic inspection and replacement is needed.

another69
04-20-2008, 06:56 PM
I was under the impression that the hose ends were the same, just the hose itself was differant(?). 90% of the fuel lines on my car are less than 1 year old, so I'm not exactly going to tear it all out yet. When that time comes, though, whose line do you recommend?

As for assembly, the Aeroquip stuff I've been using is pretty easy- a little lube and it screws right in. Comes apart pretty easy too.

Any ideas on life expectancy with the stuff I've got? (Their website was pretty vague).

Thanks. By the way, Carl, great Camaro- very nicely done!

CarlC
04-20-2008, 09:03 PM
The ends are completely different. They are usually forged steel with a zinc plating. Another bonus for teflon is that it has a much smaller outside diameter and higher pressure rating.

Standard or teflon AN, you cannot go wrong with Aeroquip.

Due to the many different formulations for fuels manufacturers likely won't give life expectancies. I don't know how long yours will last.

David Pozzi
04-20-2008, 09:11 PM
I change my Aeroquip fuel lines after 3 years. If I don't the fuel lines leak, and I'm only running 2.5 psi for weber carbs! I've had several hose failures when I went longer than 3 years. I really think 3 was pushing it. I only run race gas, which is probably harder on the lines.

Oil lines last a LONG time.
David

another69
04-21-2008, 05:14 PM
Well, I wish I would have known earlier- damn.

Carl- is the steel stuff still 37 degree? I looked around and the teflon lined stuff I saw in mail order catalogs is advertised as power steering and brake line mainly. Is this what you use? I'd really like to run my lines once and pretty much forget about them. (that's what I thought I was doing when I first ran them!)

David- where do your lines leak from?

Is it safe to assume that most rubber fuel line (given equal pres. fuel, etc.) will have the same lifespan, or is the braided AN stuff inferior in some way? I'm asking because the article I read (PHR) basically said that the "cheap" socketless line they were using would last alot longer (than braided). Are they wrong or am I missing something?

CarlC
04-21-2008, 07:30 PM
AN spec is 37* only. Yes, it's the brake/PS type.

I don't know if the socketless vs. stainless braid base material is the same. But, as David pointed out, the more aggressive the formulation, the lower the life of the line.

another69
04-22-2008, 05:46 PM
I'm assuming they sell -8 and -10, but all I've found so far is up to
-6. I guess I'll have to look deeper.
Thanks again.

CarlC
04-22-2008, 10:55 PM
What does your fuel system consist of, and what are the engine specifications?

Teflon is not available in -10. -6 and smaller is the most popular. -10 for fuel is monsterous.

Skip Fix
04-24-2008, 01:48 PM
Man my line on the TA has been on there darned near 15 years and no leaks and an electric pump dead headed. But then there haven't been alot of miles in that time:)

David Pozzi
04-24-2008, 10:31 PM
Well, I wish I would have known earlier- damn.

Carl- is the steel stuff still 37 degree? I looked around and the teflon lined stuff I saw in mail order catalogs is advertised as power steering and brake line mainly. Is this what you use? I'd really like to run my lines once and pretty much forget about them. (that's what I thought I was doing when I first ran them!)

David- where do your lines leak from?

Is it safe to assume that most rubber fuel line (given equal pres. fuel, etc.) will have the same lifespan, or is the braided AN stuff inferior in some way? I'm asking because the article I read (PHR) basically said that the "cheap" socketless line they were using would last alot longer (than braided). Are they wrong or am I missing something?

I've had no leaks near the fittings.
The worst spots are where the hose is curved the most. One was right behind my head where the feed hose bends to connect to the LF carb, the next is where the line makes a loop over the distributor and back to the left hand carbs. I used to use Russell hose, then changed to Aeroquip stuff, all stainless steel braided, no teflon. I need to either find some two layer hose or go to all Teflon.
David

MuscleRodz
04-25-2008, 05:50 AM
I have been using Aeroquip for many years in the aviation industry. I would only use Mil-Spec hose if you want any life out of them. Should last 10 years easy.

CarlC
04-25-2008, 06:37 AM
One was right behind my head....

What? No Richard Prior for you eh???

another69
04-25-2008, 11:50 AM
Carl- I'm only running pump gas, and a pretty typical 406 SBC with a mechanical pump. I currently run -8 from the tank to the pump, then -6 to the carb. (no regulator, 80gph pump) I will soon upgrade the pump and add a regulator, so I'll probably run -8 from pump to regulator, then -6 to each carb bowl. I think -10 would be ok for the inlet of the mech. pump, but probably wasted money on my motor.

Anyway, here are the motor specs:
GM 400 block .030 over, Scat crank + rods
10.25:1 compression w/ flat top pistons
Dart pro 1 200cc heads matched to RPM Airgap manifold
HP750 carb (pro systems)
Comp XE 284 cam (.507 .510, 240 246 @.050)

Nothing really wild, I probably don't need a ton of fuel yet, but a solid roller is in the plans soon(the heads will probably limit me), so thats why the pump is changing.

Skip Fix
05-19-2008, 07:50 AM
Well maybe the switch to full pump gas 2 years ago from a race gas mixture from the old motor,but decided to fire up the TA for the first time in a while and after swapping carb spacers. well the dreaded AN line leakage was TERRIBLE. Dripping out until I released the presure on the line. But hey 20 years isn't bad!

parsonsj
06-01-2008, 04:21 PM
Well, my fuel line hose failed today. 2 years of use, less than 2000 miles of driving.

Russell ss braided stuff. I can't believe it! Made quite the mess too.

So, I'm changing out all my hose and ends. Where can I get mil-spec stuff?

jp

andrewb70
06-01-2008, 08:36 PM
John,

I would look into teflon lined hose. It is not as bendy as the rubber hose but it will not react with the fuel.

Andrew

MuscleRodz
06-01-2008, 09:02 PM
Well, my fuel line hose failed today. 2 years of use, less than 2000 miles of driving.

Russell ss braided stuff. I can't believe it! Made quite the mess too.

So, I'm changing out all my hose and ends. Where can I get mil-spec stuff?

jpAircraft Spruce. I know your familiar with them. Aeroquip medium pressure (303 I think) or Stratoflex (don't remember the equivilent). You will need a mandrel tool to install the ends on. Let me know if I can help.

parsonsj
06-01-2008, 10:13 PM
Thanks guys. I've just done a complete inventory of my plumbing setup and I'm going to re-do most of it in hardline. So I need some adapters and such.

I will still need two hoses, (8AN supply, 6 AN return).

Mike: do you have the mandrels for assembly? How would I go about spec'ing them so they fit? The 8AN supply has a 45 degree fitting on one end, and a straight on the other. The return line has a 90 degree on one end, and a straight on the other. I guess all I need to supply is the length since clocking won't matter.

jp

B Schein
06-02-2008, 07:50 PM
John if you want the really nice stuff you need to get in contact with Brown and Miller Racing Solutions (BMRS) here in Charlotte they make 90% of the hose used in nasty car and its there own proprietary hose every thing is crimped= very light. In my opinion the best hoses you can get. Its what I plan to put on my car one day.

parsonsj
06-02-2008, 07:59 PM
Brian, I might do that. After this next re-design, I'll only have a couple of feet of hose in the whole fuel line setup. All the rest will be hard line. I'm hoping really high quality hose won't kill me on price if it is only a couple of feet in length.

jp

MuscleRodz
06-05-2008, 10:21 AM
Thanks guys. I've just done a complete inventory of my plumbing setup and I'm going to re-do most of it in hardline. So I need some adapters and such.

I will still need two hoses, (8AN supply, 6 AN return).

Mike: do you have the mandrels for assembly? How would I go about spec'ing them so they fit? The 8AN supply has a 45 degree fitting on one end, and a straight on the other. The return line has a 90 degree on one end, and a straight on the other. I guess all I need to supply is the length since clocking won't matter.

jpI have the mandrels. They won't work on the elbowed fittings though. You can also use a fitting to lock in the hose fitting down so it can be screwed into the hose.

Hard line is a good way to go as long as it has a flex point between the frame and motor so as not to fatigue the hard line.

Skip Fix
06-06-2008, 09:40 AM
Pondering going hard line myself after the race this weekend.

Rick Dorion
06-06-2008, 02:09 PM
I'm not suggesting anyone change their plans; this is just information.

I have hardline and aeroquip socketless and use Sunoco pump gas. The socketless is 5 years old, no fumes, no degradation (I cut a piece off and examined).

parsonsj
06-06-2008, 02:21 PM
Someone else told me that Aeroquip AQP was the way to go. Socketless Aeroquip is AQP lined, so that fits.

Thanks Rick.

jp