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Fuel lines failing because of ethanol blend fuel?

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Old 10-15-17, 10:40 PM
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OR Fuel lines failing because of ethanol blend fuel?

I have several Earls fuel lines that have failed leaking in the center of longer length fuel lines, after being in service for a reasonable amount of time to completely rule out incorrect installation. Lines have absolutely no way to have ever been punctured, crimped or smashed, overheated, or any stimulus or abuse other than the fuel causing the lines to degrade and fail.

Is this a notable issue at all in the community for others? Degrading fuel lines that leak unprovoked.

What have people done about this issue that have had this problem?

Running on 92 pump gas, almost exclusively from Cheveron Brand fuel in greater Portland Oregon and southwest Washington area.

(“Legit” Purchased from Summitracing) Earls Brand Earls Perform-O-Flex Hose.

On Earls Fittings.


What are the options from people that have had this issue while staying on readily avalible generic pump gas?

Can I replace all the lines with something that will not give me any issues in the future utilizing the existing earls -6 fittings?

Its become dangerous, frustrating and infuriating that such a perceived expensive solution for something as simple as a hose is failing in this way. Only reason I was willing to go with those was the perception that it was as close to a foolproof method of retaining fuel in an untested environment as I knew at the time. Now they randomly spray pressurized fuel out the sides of the tubing into a running engine bay with exposed turbo manifold and turbo at exhaust temperatures for seemingly no reason...

Does anyone that has had this issue have some good advice?

Is our blend in the PNW causing the issues? I have read before we get a fairly high percentage ethanol blend here and for longer than most?

Are there known proven solutions tested over time in this area specifically that will not give me issues in the future?


I even removed the SS braided external jacket off the line to 100% confirm that the line is leaking randomly in the middle of the tube.

I have had ~5 such failures with this specific line and even a different batch of replacement line not believing/confident it was the line at fault.

Last edited by rotarypower101; 10-15-17 at 11:02 PM.
Old 10-16-17, 07:47 AM
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You'll want to run PTFE lines and fittings, they are ethanol friendly and good for use with E85 (so they'll handle the ethanol found in "normal" gas as well).

Only problem is that the fittings are pricy

Last edited by fendamonky; 10-16-17 at 07:49 AM.
Old 10-16-17, 09:47 AM
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Originally Posted by fendamonky
You'll want to run PTFE lines and fittings, they are ethanol friendly and good for use with E85 (so they'll handle the ethanol found in "normal" gas as well).

Only problem is that the fittings are pricy

Is there a specific system you have in mind?

Is it a popular enough that there would be several examples from me to draw off from to kind of extrapolate how well it works for others?


my ultimate desire would be to find a system that would allow me to use the -6AN standard, as I have changed literally everything over to it, save for in tank between the pump and outlet at the tank.
Old 10-16-17, 11:21 AM
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You can get made-to-order -6 Teflon hoses

Pegasus will make you custom hoses

https://www.pegasusautoracing.com/is...sp?RecID=18636
Old 10-16-17, 05:30 PM
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Originally Posted by DaveW

Those are nice, no doubt.

Was hoping for something a little more off the shelf, that could get ridiculously expensive quickly to outfit all my small sections and special fittings.

Is PTFE the go to material for issues like these?

How ridged is the line with PTFE? I don't have any particularly extreme bends, but the ability to articulate around and position to specific hold down points would be advantageous.

And is it possible to pick up lengths so the user can assemble from existing fittings?

Last edited by rotarypower101; 10-16-17 at 05:35 PM.
Old 10-17-17, 05:45 AM
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Originally Posted by rotarypower101
And is it possible to pick up lengths so the user can assemble from existing fittings?
You need to have ptfe specific fittings, so you wouldn't be able to reuse your old fittings.
Old 10-17-17, 06:29 AM
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That's odd, the 10% ethanol shouldn't cause issues, or id imaging everyone would be having this issue, where is it occuring at bends at the clamps?

ive had to replace very old fuel lines on most of my old cars but only once and they lasted years
Old 10-17-17, 07:29 AM
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Originally Posted by KompressorLOgic
That's odd, the 10% ethanol shouldn't cause issues, or id imaging everyone would be having this issue, where is it occuring at bends at the clamps?

ive had to replace very old fuel lines on most of my old cars but only once and they lasted years





I had the same thought, but I didn't say it because I'm using Summit (or other source) push-on rubber hose with 93 octane E10 (street gas, specified for availability at or near the track each week by the series I run) on my F2000 racecar (Zetec engine which uses high pressure fuel pump for injectors), which probably doesn't see the same engine compartment temperatures that an FD does.

Having said this, the only difficulty with using this hose for fuel lines is that they tend to harden up after (>5) years of use (even with zero-ethanol race gas) and have to be replaced. I've not had any other issues in the ~8 years I've been using them with E10.

So, rotarypower101, maybe, even though the supplier and the brand are legit, you (both times) got a batch of off-spec Chinese hose. I'd try again from a different source to see if the issue repeats, even though I definitely understand your reluctance to take a chance on them again.

Last edited by DaveW; 10-17-17 at 08:22 AM.
Old 10-17-17, 02:56 PM
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Originally Posted by rotarypower101
I have several Earls fuel lines that have failed leaking in the center of longer length fuel lines, after being in service for a reasonable amount of time to completely rule out incorrect installation. Lines have absolutely no way to have ever been punctured, crimped or smashed, overheated, or any stimulus or abuse other than the fuel causing the lines to degrade and fail.

Is this a notable issue at all in the community for others? Degrading fuel lines that leak unprovoked.

(“Legit” Purchased from Summitracing) Earls Brand Earls Perform-O-Flex Hose.

On Earls Fittings.

I even removed the SS braided external jacket off the line to 100% confirm that the line is leaking randomly in the middle of the tube.

I have had ~5 such failures with this specific line and even a different batch of replacement line not believing/confident it was the line at fault.
Originally Posted by DaveW
I had the same thought, but I didn't say it because I'm using Summit (or other source) push-on rubber hose with 93 octane E10 (street gas, specified for availability at or near the track each week by the series I run) on my F2000 racecar (Zetec engine which uses high pressure fuel pump for injectors), which probably doesn't see the same engine compartment temperatures that an FD does.

Having said this, the only difficulty with using this hose for fuel lines is that they tend to harden up after (>5) years of use (even with zero-ethanol race gas) and have to be replaced. I've not had any other issues in the ~8 years I've been using them with E10.

So, rotarypower101, maybe, even though the supplier and the brand are legit, you (both times) got a batch of off-spec Chinese hose. I'd try again from a different source to see if the issue repeats, even though I definitely understand your reluctance to take a chance on them again.
A PSA I did earlier this year. There is no explanation other then inferior rubber for the duration and time used. The hoses were used in the engine bay area, with OEM hardlines.
If you replaced the OEM hardline with the Earl's SS lines, my personal opinion would be to go back to hardline, either OEM or custom. Custom would still be cheaper, and minimize use of hoses when possible.

FYI, the hoses were Parker/Jiffy Hose push-on which stated Made in USA.
https://www.rx7club.com/3rd-generati.../#post12193695
Old 10-17-17, 04:46 PM
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Link to choosing the right hose

Just got this in an email and thought it would be useful:

https://www.pegasusautoracing.com/document.asp?DocID=TECH00112&utm_source=201710-2&utm_medium=email&utm_campaign=201710-2

They say, for any ethanol, use Teflon lined hose, but as I said above, the Nitrile-lined hose has worked for me with E10.

Last edited by DaveW; 10-17-17 at 05:46 PM.
Old 10-17-17, 09:37 PM
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Originally Posted by fendamonky
You need to have ptfe specific fittings, so you wouldn't be able to reuse your old fittings.

That is unfortunate.

I am going to look into this solution and see if there is anything out there that would allow my specific request.

I have to believe this would be a desirable enough solution for someone to have produced PTFE in a "standard" -6 fitting compatible.
Old 10-17-17, 09:50 PM
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Originally Posted by rotarypower101
That is unfortunate.

I am going to look into this solution and see if there is anything out there that would allow my specific request.

I have to believe this would be a desirable enough solution for someone to have produced PTFE in a "standard" -6 fitting compatible.
Uhhhh, I do not believe this is correct. PTFE is essentially teflon. PTFE lines have teflon on the inside which is super slippery but are still rubber and braided on the outside.
Regular SS line is (Outside to inside) SS braid>Rubber
PTFE lines are (Outside to inside) SS braid>Rubber>PTFE lining.
For fittings or any metals that contact e85 or methanol, it is recommended to go stainless steel fittings which have less chance to rust.
Hence why it is recommended to use a stainless steel fuel filter instead of paper element or regular steel.
Old 10-17-17, 09:55 PM
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Originally Posted by KompressorLOgic
That's odd, the 10% ethanol shouldn't cause issues, or id imaging everyone would be having this issue, where is it occuring at bends at the clamps?

ive had to replace very old fuel lines on most of my old cars but only once and they lasted years

Thats what I was hoping to find out, if it was a wider issue, yet I have never seen issues quite like mine around here.

Every failure has been ~in the center sections of the tubing, well away from the fittings, so I am as confident as I can be when I assert it is not from improper assembly. I never placed the tubing line in any clamping mechanism on assembly either just to be perfectly clear.

This latest one is in a ~12" strait unbent length on the driverside firewall . And that was it, thats the catalyst for it being absolutely ridiculous in my mind that these are failing.

I don't know if you have ever worked with that stuff, but it can be a pain, but I have the process down where I don't mar the fittings or have issues with loose SS wires or misaligned or partially threaded fittings.

I am VERY persnickety about those things even for someone that has passion for the car. Each line was constructed test fitted and pressure tested before final installation.

It really is something I didn't ever want to have to consider again, I really wanted a confident trustable solution for pressurized fuel..so this is damn near my worst nightmare realized of any of the work that I have done and need to trust and rely on.

Last edited by rotarypower101; 10-17-17 at 09:58 PM.
Old 10-17-17, 10:06 PM
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Originally Posted by DaveW
So, rotarypower101, maybe, even though the supplier and the brand are legit, you (both times) got a batch of off-spec Chinese hose. I'd try again from a different source to see if the issue repeats, even though I definitely understand your reluctance to take a chance on them again.

Its possible, but from digging around there seems to be a unspecified disclaimer that I have no way to correlate with my specific batch of line.

Maybe I am reading too much into the statement, but it seems like there "was" perhaps incompatible line at one time?


https://www.earls.com.au/faq/

Are Earl’s hoses OK to use with E85 and Methanol?
Earl’s Teflon – lined Speed-flex and Ultra-Flex hose has always been fine for use with these fuels. For the last few years all Earl’s rubber – lined hose varietiesPerformo-Flex, Auto-Flex, Pro-Lite 350, Pro-lite Ultra and Superstock – have had a new inner liner which has made them compatible with almost any fuel – E10, E85, 98 Octane, Methanol as well as more traditional hydrocarbon fuels and oils. So yes, NO WORRIES about E85 with Earl’s.
Old 10-17-17, 10:37 PM
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Originally Posted by silentblu
Uhhhh, I do not believe this is correct. PTFE is essentially teflon. PTFE lines have teflon on the inside which is super slippery but are still rubber and braided on the outside.
Regular SS line is (Outside to inside) SS braid>Rubber
PTFE lines are (Outside to inside) SS braid>Rubber>PTFE lining.
For fittings or any metals that contact e85 or methanol, it is recommended to go stainless steel fittings which have less chance to rust.
Hence why it is recommended to use a stainless steel fuel filter instead of paper element or regular steel.

From simply looking at mine, destructively disassembling it:

These specifically have (outside to inside) a SS braided external mesh, a braided white fabric/material, a cast "rubber material" with integrated SS semi externally exposed braided mesh, and a "thicker" cast inner liner bonded to the same layer.



It would be very difficult to photograph, so you will have to take my word for it...

But when I shine a bright light through the used line, I can see a dull matte/flat surface with a obvious “bumpy” non smooth surface. Almost like there are a multitude of little tumors or bulges ~ 1/4" diameter down the length of the tubing impinging inside the line into the flow path. The lines also seem to be significantly less flexible, and I seem to be able to "pick" chunks of rubber away from the internal line far easier than we associate "rubber" with being able to do. Its more brittle than stretchy and resilient.

If I look at a piece of excess line presumably from the exact same batch, I see a smooth glossy uniform bore.

So it seems like the fuel is doing something to the interior of the line...


Fuel lines failing because of ethanol blend fuel?-9exddnv.jpg




Fuel lines failing because of ethanol blend fuel?-0jxcrym.jpg
Old 10-17-17, 11:53 PM
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It appears they do make a -6 AN line that is PTFE lined by a few manufacturers.

Whether any of these are directly compatible with my existing Earls fittings is another matter entirely, off by parts of a mm, and they will not work with the compression nuts either too big or too small.

https://pitstopusa.com/i-23901888-fr...ack-cover.html

Product Description: Hose, Series 6000, 6 AN, 10 ft, Braided Stainless, PTFE, - Black, Each

Pit Stop USA sells Fragola 6000 Series P.T.F.E Lined Stainless Hose - #6 - 10ft w/- Black Cover
Old 10-18-17, 12:30 AM
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It seems this specific line “should be” compatible based on simple measurements.


https://www.holley.com/products/plum...arts/400060ERL

Earls -6 PERFORM-O-FLEX HOSE

ID .344"

OD .547"


http://fragolaperformancesystems.com...e-with-covers/

Fragola -6 6000 Series P.T.F.E. Lined Stainless Hose With Covers

ID .312""

OD .505"



Earls Fittings

OD on slip fit tube .340-.358” as measured on the few loose fittings I have

ID on wedge lock nut 0.480” as measured



So ~0.04” smaller on the outside diameter of this PTFE line. which could slightly be mitigated by permenently using something thick to retain the SS braided mesh while assembling.

Not sure if that will be enough to foul the wedge lock on these earls fittings, the earls fittings are extraordinarily tight, but the difference doesn't seem negligible...

I am only working with ~1/3 of the force developed by the Earls Line with the Earls Fittings.

Think I am going to keep looking around, order some test line and see if I can adapt what is avalible to the existing fittings.

This is quite possibly a very stupid question, despite the fuel cooling the PTFE liner... doesn't PTFE have a fairly low thermal threshold? ~260C to degradation effects?

https://en.wikipedia.org/wiki/Polyte...thylene#Safety

That wont really be a factor in the bigger picture though?

Last edited by rotarypower101; 10-18-17 at 12:33 AM.
Old 10-18-17, 05:59 PM
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Originally Posted by rotarypower101
...This is quite possibly a very stupid question, despite the fuel cooling the PTFE liner... doesn't PTFE have a fairly low thermal threshold? ~260C to degradation effects?

https://en.wikipedia.org/wiki/Polyte...thylene#Safety

That wont really be a factor in the bigger picture though?
260C = 500F. If the fuel line gets that warm you'll have way bigger issues than the PTFE degrading...

Last edited by DaveW; 10-18-17 at 06:23 PM.
Old 10-18-17, 11:29 PM
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Was thinking more worst case scenario...

I do have a specific spot, a single line that pokes out from behind the LIM going to the FPR that has a relatively close direct line of sight to the turbo that I run with solid fittings (changed them out not pictured, however this is how I would like to route the line with more heat shielding obviously), but in honesty I would like to run a piece of tubing around given the ability to do so. Strictly for aesthetic reasons if the line would handle the abuse.

I do run a SS heat shield over the area, again, worst case scenario.

If you look at this photo the line is intolerably close to the turbo because of the horrible placement the earlier turbo manifolds came with.
The photo is somewhat deceiving, but still, its in a poor place.

Fuel lines failing because of ethanol blend fuel?-hwdltko.jpg

Last edited by rotarypower101; 10-18-17 at 11:46 PM.




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