Fuel line failed

johnymd

Club Member
I've just tried to have a quick readup on E85. I have heard of it but had no idea what is was. Still a bit confused. Is it available at petrol stations? Is it what I've been using for years without knowing it? Someone please enlighten me.
 

SKiddell

Well-Known Forum User
E85 is something completely different john and its highly UNlikely you’ve been using it without knowing as it would require a complete remap due to the burn properties and chemical make up plus you would end up using considerably more as its calorific value and energy density is lower than non ethanol blended petrol (we tested E85 on Matts race car with mixed results some years ago) its also fairly uncommon.

I was considering using at one point but the gains on an NA car would be minimal, the availability poor and the mods needed to proof the fuel system expensive
 
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SKiddell

Well-Known Forum User
But Ethanol in fuel is a growing concern to those of us with older vehicles

Ethanol will rot rubber, cork, plastic and, given time, pretty much everything else on Gods earth

Ethanol is widely used in the production of fuel and is common in the lower grades
A lot of the high octane fuels available use ethanol as a detonation suppressor so if you need high octane fuel and wish to stay away from ethanol go for BP 97 or 98 which claims not to use ethanol

The worse issue is water vapour contaminating ethanol blended fuel, ethanol is hydrophilic (greek for water loving) meaning it will absorb water just by looking at it and water can "phase separate" the ethanol out of the mixture, might not sound bad but I don’t fancy having 0.5 of a gallon of pure ethanol sitting in my 10 gallon tank and leaning out the mixture on my lovingly built engine and then futher insulting me by rotting my aluminium tank and all the rubber bits in between
 
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johnymd

Club Member
Thanks for the enlightenment Steve. When I saw E85 mentioned in this thread I started to think this may be what some of us were using.

I've just read a very good article on Hot Rod that explains the situation very well. It is suggested that anyone using a rubber based hose should replace all the hoses every 12 to 18 months, maybe sooner if you dont use the car very often or leave standing over the winter period. This would explain why Dave's and my hoses have failed in what we thought was a short period of time but turns out to be about right.
 

johnymd

Club Member
Budget Solution: J30R9
If you just want reasonable longevity at a modest cost without regard to appearance, the budget, parts store solution is hose meeting SAE standard J30R9 or (just becoming available) the further improved J30R12. Although these hoses can operate at up to 180 psi, what really makes them better than generic parts store hoses are the improved materials they're made from, designed for contact with alcohols, diesel, oxygenate additives, and oxidized gas. Although the outer walls are usually still hydrogenated nitrile butadiene rubber (HNBR) or CPE, internally there's a thin fluoroelastomer, FKM, or Viton core. Collectively, the design also resists cracking caused by sour gas and reduces emissions because fuel can't evaporate through the hose. XRP is said to be working on a braided racing hose conforming to SAE J30R9 that may eventually replace traditional CPE-cored formulations. This would offer significantly improved durability but still keep down the price of race hose. We'll keep you updated on XRP's progress. While J30R9 is better than old-school fuel hose, like any rubber-based hose, it, too, eventually deteriorates. In fact, domestic OE new-car manufacturers have pretty much switched to Teflon-based hoses.

High-Tech
Solution: Teflon
We may call it Teflon, but that's actually DuPont's trade name for polytetrafluorethylene (PTFE), a synthetic fluoropolymer that is stable at very low and high temperatures and chemically inert to everything except acid. PTFE hose is so durable that, absent crash damage and assuming proper installation practices, it should outlast the life of the car.

Most who know me will have already worked out I'll be going down the top option :)
 

jonbills

Membership Secretary
Site Administrator
I don't think it would be a reason not to use it, but PTFE releases hydrofluoric acid in a fire, which is proper nasty. so if you use PTFE, and your car catches fire, salvaging bits afterwards could be very dangerous.
 

racer

Club Member
I believe we have the Euro regulators to thank for this. I did read somewhere that a certain percentage of fuel sold has to contain a minimum of5% Ethanol, witch may increase to appease the Planet huggers.

We all need to research witch supers don't contain any.

Here's the first one that does so avoid

http://www.tescopfs.com/momentum99/specifications

If anyone finds any others add to the list and we can creat a sticky.
 

SKiddell

Well-Known Forum User
I run my 370Z almost exclusively on V Power - hopefully a modern car should be ok shouldn't it?

Its a valid point Rob, its easy to get fixated on the corrosive nature of ethanol/water but its not just its corrosive effect but also that the materials used in "older cars" were never designed to cater for it. Newer cars are designed to be more ethanol tolerant and accept small percentages (5 and 10%) of ethanol in the fuel allowing governments and petrochemical companies to help introduce "E" fuels.

Nissan vehicles manufactured from 1 January 2004 onwards are capable of operation on ethanol blends up to E10 (10% ethanol), :

But another downside of ethanol doped fuel, is its calorific value and the potential reduction in MPG

Interestingly though all the £millions of potential damage to older cars is never mentioned when the green credentials of ethanol is banded around

So Ethanol is good for the petrochemical companies (watering their fuel down plus people have to buy more), government (people have to buy more so more tax revenue), dumb greenies (who believe that its actaully good for the squirrles) etc but the consumer gets a more corrosive fuel that returns less MPG and less energy per litre.....looks like we're getting our pants pulled down again
 
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NikWilson

Well-Known Forum User
Had the same thing on my 240Z running standard carbs and fuel pump about 2 months ago. Fuel started to weep out of the hose in various places in the system. All seem to happn at the same time. the car had been left to stand for a long time and may have had fuel left in the lines.

I am running the car on V power with Castol lead substitue.

Had to replace all the fuel hoses on the car that were specific fuel hoses that had been manufactured with material overbraiding.
 

toopy

Club Member
Found this recently on an American site, never heard of non-conductive hose before now!



"First of all, if you are using PTFE (Teflon) hose to transfer fuel, you need to make sure the hose has a 'conductive core'. This is easily recognized as the inside diameter of conductive core hose is black--vs the off-white color of 'non-conductive core' PTFE hose. This is important as fuel is a non-conductor AND it generates a static charge as it passes through PTFE hose. The black color in the PTFE conductive core hose is actually carbon--which allows the static electricity to pass through the hose/fittings assembly to ground. Without that, the static charge builds in the hose, looking for a path to 'ground' --not a good situation. All PTFE fuel hoses used on production cars are conductive because of this issue."
 

johnymd

Club Member
I'm still running rubber hose but need to look into replace it. I use a standard tank so need to be able to connect to the tank outlets/inlets with a jubilee type connection. Can this be done with PTFE or do I need to weld a boss onto the tank for new connections. How has everyone on this forum dealt with this problem or are you all just waiting for the hoses to leak before changing them?
 

johnymd

Club Member
Out of curiosity, when did vehicle manufacturers change over to PTFE? Does the problem effect all z's up to the 350? The replacement of all rubber hoses should really be part of an MOT if its as dangerous as I think it is.
 

AliK

Vehicle Dating Officer
Staff member
Club Member
All that I've read suggests they moved with the introduction of unleaded and disappearance of leaded. Someone else may know more.



Ali K
 

toopy

Club Member
I'm still running rubber hose but need to look into replace it. I use a standard tank so need to be able to connect to the tank outlets/inlets with a jubilee type connection. Can this be done with PTFE or do I need to weld a boss onto the tank for new connections. How has everyone on this forum dealt with this problem or are you all just waiting for the hoses to leak before changing them?

I have read that you can use the normal jubilee type clips with the PTFE hose, but that the
inner ptfe part does not expand as much as normal rubber hose would.
So trying to get a piece that is the correct internal ID over the return flow reducer on the fuel rail
could prove difficult, you may need a larger diameter, but then it wont fit properly on anything else!
 
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