E85, Fuel lines and Corrosion

[andrew_mx83]

So i am in the midst of converting my race car over to E85 and have discovered that its more of a can of worms than i thought!
I went out and bought a length of big stainless pipe, with the idea of making up a new fuel line from cell to carb with some braided hose as joiners.

After some basic research (most of which is over my head) it seems that the idea of ethanol "eating" aluminium is rubbish. from my reading it seems the biggest problem is the corrosion between dissimilar metals.
now ethanol is electrically conductive, unlike gasoline which is where the problem lies. So if you have a steel fuel tank, copper fuel line and alloy carbs there is a bunch of changes in metal which will result in corrosion at the joins?
does the corrosion only occur "electrically"?


im my application i now think stainless is the wrong choice -sure there will be no oxidisation in the fuel hard line, but other points in the system may be "weak spots" where the material changes.

it goes:
Poly fuel cell w/aluminium fittings
rubber/braided hose
Aluminium bodied fuel pump (not sure about internals). currently has brass fittings but they are tiny so i want to turn up new ones, they can be whatever material.
rubber/braided hose
stainless hardline (factory line is probably too small but appears to be a ferrous metal of some sort)
rubber/braided hose
aluminium float bowl w/brass float, then currently plastic pipe to other fuel bowl (i want to replace the plastic pipe with something else)


in the above scenario by switching to an aluminium line and fittings on the pump, i would have the same metal everywhere in the system bar the actual floats. im feeling like this may be a better option... in which case would plain old rubber hose be better than stainless braided?

would an earthing rod inside the tank help at all? keep the fuel grounded all the time so it cant carry a charge? electrical stuff isnt my bag, i may be way off here...

[stradlater]

I've been told rubber line for the main fuel line rather than braided because of the same issue....

You COULD always use that 'bomb proof' stuff they use for LPG lines, it's braided but it's material braided rather than metal braided. Some sort of polycarbonate. The internals are rubber on these.

I'm still not sure what I'll do with mine, I have a steel tank, aluminium fittings & pumps, alloy surge tank, I'm pretty much f'ed. Although they are all earthed so it should be ok.

[Bazda]

You should be using Braided teflon hose for the fuel lines.
The rubber ones wont last long and they swell up from the Ethanal.

[punkture]

Google electrolysis if you want to
Know more about
Why it does it, I'd say all same fittings and lines and you'll
Be fine, that being said I doubt there will be that much current that the electrolysis is so damaging

[thechuckster]

if you're really worried about E85 being left in the system, take a leaf out of the nitro/meth drag racing book - fit an air-fitting at either end of the fuel system, and use compressed air to push out the remaining fuel after and event before pumping some normal fuel thru it for moisture exclusion while stored.

[andrew_mx83]

3rd try's the charm, chrome keeps deleting everything whenever i try to reply to this thread GRRR.


so i wiki'd Electrolysis and Galvanic Corrosion (dissimilar metals) and im not that much wiser -most of it was way over my head. i did like the idea of a sacrificial anode, basically a "weaker" metal immersed in the water/fuel which is designed to corrode away first leaving the "stronger" metals untouched. not sure if the particles that corrode away will be big enough to block up filters/jets etc but i believe they are measured in microns so it may be ok?

either way, surely this stuff happens over a number of years, or even decades? is it a real problem or all just hype?
if i do as chuckster suggests and flush the system after each use (not what i really want to have to do, but maybe a necessary evil with E85?) i cant see corrosion kicking in for a long long time.

the PTFE lined hose probably would be the way to go, maybe get the braided stuff and strip the last inch of braid off each end so the stainless is completely insulated.
strad most LPG installs use copper and rubber lines, but i did have to get a fill line made up when i had twin tanks, its was some kind of material braided job. it was just whatever enzed/pirtek gave me, nothing special from memory. i might go in and speak to them about it

[turbotoy]

In my experience with converting my t-18 to e85 I have had no problems with corrosion. The US SAE 30R9 spec hose can be used with E85. Aluminum fittings are anodized should be no problem. My friend has been running on E85 in his evo 8 for two years no problem. I did step up to the PTFE fuel line.

[AndyTTR]

A local tuner I visited once showed us a former DA-GP drift car (S13) sitting partially dismantled in his workshop. It had been run on E85 for several years and had been sitting for nearly a year with the tank and lines full of E85 (standard tank and fuel lines). He showed us that the hoses showed no sign of degradation and there was no obvious corrosion inside the tank... it was only a casual observation, but it would appear that there's not much to worry about when running on E85?

Aside from the hype, are there any reported cases of an actual failure caused by E85 incompatibility?

[andrew_mx83]

without sounding paranoid i think its all just evil oil company scare tactics.... i will just use the stock EFI line with some braided PTFE lined hose in the middle and think no more about it.

big thanks to all who contributed.

[3jcelica]

I use r6 hydraulic line as recommended by my tunner. It is cheaper than efi line, holds higher pressures and more compatible with e85.

A lot of myths out there about using e85.

but if you have fuel tank foam and it is not the expensive yellow stuff it will melt and end up in everything

Roger

[andrew_mx83]

yep, worked out i need new foam

can i use it for a couple of weeks or just pull it out altogether until i get new stuff?

[JustenGT8]

Unless you have some low grade non EFI rubber lines, the rest i wouldn't worry about. The galvanic corrosion is a complete non issue. If you have the stainless hardline set up then just use that, it'll be fine. Teflon braided line for the joining sections and the lines will last longer than you'll own the car It does appear that a stainless mesh fuel filter is the way to go judging by my paper filter.