I am building a ground up fuel system for my resto mod 19 Z28 project.
Car will primarily be a show car (naturally aspirated at first, then maybe change things up in a few years with a blower)

System starts with a stealth 340 fuel cell from Aeromotive.
From there I plan to run hardline for the feed and return, with section of stainless flex from tank to chassis, and from chassis to regulator/motor. All AN style everywhere.

Questions:
1. Anyone have a recommendation on hardline? Brand, etc...
I am leaning towards aluminum line and oversizing everything just in case for future protection since cost is minimal between 6-AN and 8-AN.
2. Thinking of just keeping the feed and return line both 8-AN. Means I can just buy a big roll of the stuff and keep a common size of fitting to help ease confusion down the line.
No guessing game, just everything is 8-AN.
3. Any downsides to this plan apart from a extra cost up front?

(Motor will be a forged LS3 from Blueprint making around 520 HP when NA, few years down the road might be fun to really push that number up)

Thanks for any advice you can provide.

 

I have the 340 stealth setup in my car. I ran all new 6AN lines front and back. I was gonna run 8an but aeromotive said it was unnecessary and the pump an fuel lines were well matched. They said the larger 8an line wouldn't help. They said the system w 6an lines would support 700hp w a blower. I have a 430 hp NA setup now and a blower going on this winter. I told them my hp goal was about 600(ish) and they said use 6AN. I think you will be fine w the 8an but the sender is all 6 an. So increasing the lines after a 6AN won't gain much if anything. I would make sure your whole fuel system is gonna flow well. I initially had a regulator that didn't flow well enough it was effecting my fuel pump.

All this said, once my blower is on and getting tuned, if I have fuel starvation issues I'm gonna feel like a big ***!

 

I think it's a good idea to just go with -8 now. The cost won't be that much higher anyway.

I've had a good experience with Racetronix aluminum/anodized 1/2 inch line. Pretty easy to work with and low-cost.

https://www.racetronix.biz/p/aluminu...k/altube-08blk

 

I totally forgot to say. looking back, id run the 8an w adaptors to the Aeromotive 6an sender.

 

Thanks for the input everyone!

The sender on the fuel cell (15 gallon Aeromotive 340 Stealth) comes with an 8-ORB port.
Maybe internally there is a smaller part of the pump, but I am not sure.

Either way, I figure if the time comes and I want to run some stupid power, like above 700HP with a blower, then at least the lines won't be the limiting factor.
The cell is an Aeromotive unit and I built a cage and modified the trunk to accept a 15 gallon cell. So if I need to move up someday, the pump, or even entire cell swaps out and the lines are good to go.

I have been looking online for a nice 37 degree flare tool, and once you get up to 1/2" the options are really limited.
Summit has one made by Russel for $192. Think I will go that route. I don't see my self flaring stuff like crazy so this is the right level of cost/benefit I think.
The Earl's unit that Holley sells is super nice, but over $600 for a hobby builder like me, seems too steep for how often it will get used.

Thanks again for the insights. Will post updates in my build thread in my bio if anyone is interested. Will probably purchase the hardline parts tonight!

 

I thought you meant the 82-92 stealth system they sell. If you have something different then it's a no brainer. Top of the stealth for our cars looks like this. I wished it was able to deal w larger lines but according to them it wasn't necessary w their pump. If you have ORB 8 fittings, do the whole thing w that size.

 

I got mine from Speedway Motors. Was ALOT less than most of em. It's kinda basic but that's all I need.

 

I got one from Speedway also, and worked fine.

IMO, for flaring aluminum, it doesn't need to be top-of-the-line.

 

Thanks for taking the time to post the image of the tank outlets.
My resto mod has some crazy stuff done to it, so I no longer have a fuel door on the outside of the car.
Sorta long story, haha. Anyways, needed to go with a cell. Been building this setup since before they even offered that drop in unit too!

Anyways, I will stick with 8-AN for everything and move on. Thanks again.

 

With the stealth system the -6AN will support anything that 340 pump can deliver. I echo what Fire chicken stated above as Aeromotive told me the same thing. I'm running this set-up making 515 rwhp (~600 crank) and have zero fuel issues with -6AN lines. They told me I could support 600 to 630 rwhp with the 340 and -6 line. There's nothing wrong with -8 but it is more expensive and does take up more room on a tight undercarriage.

 

All good points Shifty. Think I will be tucking these lines into the tunnel as best I can.
Wish Aeromotive sold hard line. Since they don't I will be using Fragola for that job. Will still stick with Aeromotive for the flex line sections.
100% understand that -8 is way bigger than I need for now. Already have a good amount of fittings in -8 so will just keep going with that.

When the time comes (if it does) that I go for crazy power, figure this cell will have to swap out for a bigger in tank pump. At least the lines will be ready to go! haha.

Can't imagine my life not messing with this car. Just turned 41 and I have had since I was 16. Gonna future proof a bit I guess.

 

I didn't know people still use aluminum tube for fuel line. Seems like a failure waiting to happen?

 

Interesting, I've seen a lot of companies selling aluminum fuel line. Do you have any articles or examples of failures? Images or links?

I would imagine that properly constrained lines that aren't allowed to vibrate would be just fine.

I have tried stainless in the past and it was beyond a pain to work with for a novice like me. Was also interested in copper nickel, but the sizes that holley sells don't go up to 8-AN. Suggest something else?

 

Nope. Not something I've ever looked into, just always avoided it on instinct.

 

Easiest cop-out would be, PTFE braided stainless all the way. Lots of cushioned clamps along the route.

 

3/8"

This is what my original plan was!
Then I thought to myself, does that make sense? All that flex line and no flexing.
Am I paying for a "feature" that I am not using?

So I started to think hardline with some flex, more like an OEM setup.
If I am to avoid stainless and aluminum, then there is really only copper nickel and some sort of zinc plated steel, stuff like that.
Guess I am fine with those options as long as I can find it in the size I want. That being said, maybe future proofing the lines is costing me more headache than its worth and I just run 3/8" feed line.
Bite the bullet and loose the money I have spent already on -8 components I have been messing with for mock up/fabrication steps.

 

I ran flex line front to back both for feed and return. The feed has one splice for the filter and the return is a solid piece. I put in the least amount of connections possible. I ran it in the stock areas from the tank to the crossmember. As the trans tunnel opens up I started running my lines up along the bellhousing so the lines come out by the distributor. This kept them away from my exhaust. It always stressed me out how the factory lines were really close to headers. I know the trans tunnel is prone to heating up but I wrapped them in reflective insulation. My fuel tank temps sit around 100 deg on a really hot day.

 

Firechicken, what brand line did you go with?
Maybe that is still the right thing to do for my build too. No flaring, very few connections and no hardline aspects to deal with.

 

I used red horse lines and fittings. A bunch of guys I know have been happy w their products. I have been happy w them also.

 

It's ALOT eeeeeezyer to make bends with flex line than hard line. Best of all, you get multiple tries.

As far as brand, I'm not real picky. I use the Summit brand stuff alot these days. No idea who actually makes it (I'm pretty sure Summit doesn't make most of their branded stuff) butt it works fine. I'd be more concerned with making sure it's PTFE than with the brand, and using the same brand fittings as the line. Regular rubber line is HIGHLY permeable to fuel, esp if it contains alcohol; to the point that people are afraid to park their car in the garage because they're afraid the fumes will explode their house.

Another option, at least for long straight or uncomplicated runs, is annealed copper. If you do that though, definitely use at least type L (in fact that's the minimum in the codes for marine fuel plumbing), and preferably type K; and hard-solder (sil-fos) NPT-F fittings onto the ends then use NPT-M –> AN adapters with lots of Teflon tape, rather than directly flaring the line. Flared line tends to crack at the start of the flare if it's under too much stress or vibration, or if the flare is imperfect. Be aware though, the standard fittings for copper line are sized by their ID, whereas annealed copper line itself is sized by OD. That is, to fit on 3/4" soft tubing, a fitting for 5/8" hard copper is required. Bizarre and confusing I know butt that's the RW for ya.

 

I bet there's one or two line/fitting manufacturers and their products are re branded under a bunch of different companies. Obviously I don't know this but I bet for the most part it doesn't matter what brand you buy. The parts store/speed shop I know used red horse on all their cars and client cars. I had never heard of them before. I used jegs line and fittings on another car. The line looked identical to the red horse stuff. I'd make sure you use good stainless/rubber mounds and line separators/hose clamps. Take the time to rout the lines and make sure they're well supported and not going to get any abrasions. In the end a clean install w a good product should last.

 

I'm using red horse brake lines and Raceflux -6 fuel lines. The fuel line is not PTFE but they say it's safe with all fuels. So far that seems to be correct as I don't have any garage fumes and have multiple seasons and 6k miles on this setup. Not all lines are the same though but modern rubber/polymers are getting better. They were cost effective and super easy to work with compared to other brands that I also have on the car. I was worried since they weren't PTFE lined but their claims appear to be true.

 

sofakindom: Everything you said about that copper line and sizing... wow I would pay hundreds of dollars on my build to stay away from that! haha. Thanks for the info though.

Never herd of red horse before. I am sure they are great, but never seen an ad or anything. Anyways, that doesn't mean much. Just saying.

Think I will default back to my original plan. Use as few companies as possible, and do my best to have them all have tech help lines for assisting me now and future me down the line years from now.

I know this comes at a premium cost, but that's fine. Years from now I won't care about the extra $15 I spent on a fitting.

I enjoy the piece of mind of having every single component be from company X. In this situation I will have every single component come from Aeromotive.
They sell some nice PTFE, carbonized jacketed stainless line that goes with the fittings I have already bought for mock up. I will run that all the way from their cell to their regulator and from there to the LS3, and back again.
Gonna be up there in cost, but whatever.... If there is any issue ever, I have one number to call.

I'll post pics of the setup on my build thread in my bio for those interested. Will be ordering the components to finish the "cell side" of the setup soon.

Thanks again everyone for all the info.

 

From Title 33 CFR, Sections 183.501–183.590 (Federal law for marine construction):.
Obviously this is for boats, not race cars; but illustrates a principle.

 

a little late with comments, but i used Fragola PTFE lines for the full length on my LS build - both for the supply and return sides. i have an 8AN supply that has a 'Y' fitting at the back of the engine so each fuel rail is fed from the front. the rear of the rails then connect to an adjustable Aeromotive FPR. the return from the regulator to the tank is 6AN. it may be overkill but i didn't want to have to redo this later. i think the key is using lines and fittings from the same manufacturer.
for what it's worth i found assembling PTFE lines easier than the typical stainless braided rubber AN lines. i purchased a kit from Speedway to test the assembled lines after assembly. it looks to be the same as the Earl's product but at 1/3 the cost. well worth the money to ensure you don't run into any leaks once everything under the car is installed.
https://www.speedwaymotors.com/Compl...-Kit,7715.html

 

Nothing wrong with -8 for everything just abit overkill and more expensive. Just try not to mix and match different brands components like fittings and the hose itself, stick to one brand the best you can.

 

Yeah, plan to use Aeromotive 8-AN for everything (fittings and hose) and call it a day.
Maybe will drop down to -6 for the return just to ease install and save a few bucks.

 

I'd maintain the same 8an on both send and return. That way you don't have issues down the road.

 

Indeed:

The return needs to flow basically the full FP output at idle, when the engine is basically not using any fuel and the FPR is sending it all back to the tank, with as little pressure drop as possible. The FPR can't R the FP if the return line develops pressure.

IOW the bigger the FP, the more the return line needs to at least match the supply one.

Same here. FAR FAR easier. I wrap some tape (usually electrical) over the cut place first, use a wizz wheel to cut the line, chamfer the inside of the PTFE slightly with a razor blade, remove the tape and slide the nut over the line, pop the fitting into the line, drop of oil on the nut threads, tighten the nut. Took nearly as long to type that up as it does to install a fitting. It's amazing, nothing fights back, the way everything about the rubber kind does. I'll never go back to rubber for anything unless it can't be helped for some reason.

And as far as annealed copper, if it works for refrigerant (tiny molecules) when assembled properly (either flares or hard silver solder) under hundreds of pounds of pressure, for decades at a time, with all kinds of vibration and temperature fluctuations, without leeeeeeks, gasoline at 50ish psi ought to be a piece o cake.

 

Sofa,

What brand PTFE lines are you using? I've used Aeroflow, which are really nice but incredibly difficult to work with. Some of the Earl's stuff is easy to work with but is selection limited.

 

Usually the Summit brand, lately. I've also used Fragola and it seems about the same.

 

Fragola makes good hose.

For -AN fittings, I have found that Russel is okay for straight couplers and transitions. But parts with bends will have reduced ID (despite being called "full flow"), and there is about a 50% chance that any swivel will leak.

For bends and swivels, I drop the money on Aeroquip. True full size ID, and never had one leak.

Personally, I run as much hard line as possible. Less maintenance in the long run. Hose does need to be replaced periodically (I replace mine every 5 years). What is desirable at the track isn't necessarily desirable on the street. Each has different priorities that dictate different design characteristics.

I remember @alan91z28 fabricated plastic fuel line (like newer cars) in one of his build threads. Not sure how that worked out over the years but sure seemed like a slick idea instead of hose.

 

For full flow fittings I really do like the Aeroflow stuff from Australia. The problem is that it is crazy expensive and the little inventory with US distributors requires you to order from them and wait a month for them to arrive. I am using their PRFE hoses for my PS lines and they have been great, despite the difficulty in assembling them. They are rated for high pressure steering which helps make for perfectly fitting and looking lines. For my fuel system I have slowly converted to RaceFlux as their lines are the easiest to work with, super flexible and compatible with all fuels despite not being PTFE. You can also order them with fiberglass sleeve. I am at the 5 year mark or so and no signs/smells of vapors or leaks yet. Which means, everything is leaking as I type this. Below are some of the makers of line I have on my car and what I think about them.

Aeroflow - True full flow with larger ID per given AN size but hard to find and $$$$. Their PTFE lines are hard to work with and you will have bloody fingers. One of the only brands to make full flow -20 AN (coolant hoses).
Raceflux - Super Easy to work with and cost effective. My go to for most applications.
Earl's - Nothing wrong with Earl's but they aren't as "pretty" and their flexible lines are never in stock.
Red Horse - Make great flexible brake lines, can make them custom lengths too.
Russell - Horrible. bulky, ugly, hard to work with and crappy.

 

Interesting that you replace hoses every five years. So
seems very frequent. Especially if the car is just used to put put around town or to shows. I certainly will not be replacing my Aeromotive hoses every 5 years. Maybe every 10 or 15 at the earliest. Why such a short service life?

 

Fuels, especially any that contain ethanol would historically eat the rubber inside of the lines. I am sure this is still possible with some brands but most have modern polymers in their products that aren't as susceptible. I've had mine for around 5 years now and have zero issues thus far. The risk is there but so far so good. I too have no plans to change anything.

 

Oh, I was probably buying Aeroflow too, got mixed up with all the Aero____ brand names. I remember whatever I got was from Australia.

 

That's what I was told to do by the place I bought the hose.
The hoses were rock hard when I replaced them a few years ago.

I don't know the deep meaning behind all this, I just did what I was told.

 

Got it. I will ask Aeromotive tech line when the time comes.

 

yes i have continued to use nylon fuel line for the connection from the 4th gen tank / pump to the stainless hardlines... SURR makes a lot of components for this https://www.summitracing.com/parts/urr-kp1200... i have never had an issues over the years with any of their components or my builds with them... from a capability standpoint it was fine to support my ls3 with the magnsun 2300 on it that made around 600 rwhp

 

Any tricks to shaping the nylon tube or does it just go where you want?

 

as long as you maintain reasonable radius it easily curves where you want... i just followed the 4th gen tank routing pattern (likely some pics in some of my posts and then have it follow an arc down to the hardlines around the natural fuel filter area

 

I think that is what I will do next time I have the tank down. No more hose. Fits in stock clips. Never have to touch it again.

What did you do for fuel filter with the supercharged LS3?
I was thinking of doing a Y to twin parallel F-body LS1 filters so I can get service parts at any auto store. I'm not happy with the pressure regulation of the C5 Corvette filter I have now. I should go to full length lines feed and return, do it proper.

 

https://www.thirdgen.org/forums/engi...ort-coupe.html
you can see some photos in post 15 of this thread on my RAMJET (now Proflow) swap

 

I’ve got a lot of summits premium nylon braided line on my car and been on e85 for a couple yrs now with no issues. Easy to work with. its ethanol rated. Seems to hold up well so far.

i’d like to change some of it out for ptfe style for methanol. Although my buddy has some nylon braid line on his with no issues.

i got some basic AN hose line, probably russel or earls, for trans cooler lines that been on the car for a decade lol i really need to change that out for safety reasons.

 

Even with a measly Holley Blue pump, with maybe 15 psi maximum output, presented problems in that regard. Having a 5/16ths return and and a 3/8ths supply (trying to repurpose some OEM hard lines) made for all sorts of weirdness with respect to fuel pressure. That's with Holley's carb specific by-pass regulator. Upping the return via a -6AN smoothed that out.

On a similar note, it was also suggested to me (and more than once) that consideration has to be made for overcoming the effects of the g-force being subjected to the fuel under hard acceleration. The pump and lines have to have sufficient capacity to overcome that.
I've a reference to it in another thread if there's a concern.
(There's a lot of information in this thread and I apologize if that last tidbit was brought up already.)

 

As I get back to looking over the information I've gathered for my own fuel system, some other forum members (Speed-Talk most notably) have added more tech.
You may be interested in this.
https://www.speed-talk.com/forum/viewtopic.php?t=68980
Which led to this:
https://garage.grumpysperformance.co...-system.14125/

 

Not clear what the take away from the links posted is.

I briefly looked into the links and they are taking about stock-ish setups and drag racing wheelie issues.

Any specific insights you were trying to add/ point out?

 

Page 3 of the Speed-Talk link offered this: 15 feet of line in the calculation which is close to what I have in the car. For density I used water but gas is actually lighter. If you work it out per foot of fuel line, with gas you'll get about 1/3 psi per foot of fuel line with a 1 gee launch. So 15 feet of fuel line will be more like 5 psi the pump will be fighting in a 1 gee launch.

So, the insight is that it's not only about GPH and correctly sized lines butore about how the pump needs to have some reserve capacity to overcome those forces generated under hard acceleration.
1/3 PSI per foot of fuel line seems to be a common value that's been put out there.
1 G is easy enough to achieve.
Of course, if you're not a racer then it's a moot point.
In my case, with the little Holley Blue pump I mentioned, I could out pace the pumps output and have little to no fuel pressure at the end of a run. At best it might supply 14-15 PSI (and low in the GPH department).
I'll be stepping that up with a pump that'll push 45 PSI to the front mounted regulator, then turning it down to 5 PSI for the carburetor.
I'm guessing your mileage will vary!

 

To put permanent bends in it you can fill it with sand (to keep it from collapsing) and use a heat gun on it. Gotta be REAL thorough about cleaning it out afterwards obviously.

Seems like a long thin spring, something like a M1 operating rod spring, might do as well, but I've never tried it. You could pull it through to the point you need to make your bend, and out afterwards, with a piece of wire.

 

hmm ... seems like we might have more common interests than just cars!

also i have noticed that the nylon tubing is not all made the same and some a lot more common to kink ... i have had good results with the SURR and this also applies to their specific nickel-copper brake line tubing as well vs others