fuel tube

bones · Post by **bones** » Sat Dec 11, 2010 11:24 am

Hi all, is alloy or copper tubing ok to be used with fuel ??. Rubber seems to crack alot ,and we all know rubber with holes in is not good, as my parents keep telling me when they see me.

rich

DaveEFI · Post by **DaveEFI** » Sat Dec 11, 2010 11:42 am

Well, carbs are made of an aluminium alloy and brass for the jets etc - which contains copper. Copper fuel lines were used on old cars - but they need to be used with care as they can fracture if flexed. As can all metals.
Plated steel is also used for fuel lines - tanks are usually steel. Semi-rigid plastic is also found on fuel lines.

However, you'll likely need flexible connectors on some places. A good quality 'rubber' designed for the job should have a long enough life.

I've heard it said some older 'rubber' hoses are attacked by unleaded petrol. The bulk stuff I used on my EFI high pressure side is marked 'unleaded'.

softdash3.9 · Post by **softdash3.9** » Sat Dec 11, 2010 12:40 pm

Do not use the clear nylon tube wth the braiding, it shrinks with petrol over time, talking from personal experience having spraying a red hot engine wth petrol, a few months after fitting it neatly, it shrank and pulled off the carb

gelmonkey · Post by **gelmonkey** » Sat Dec 11, 2010 3:27 pm

Rich
Dash 6 all the way from one end to the other.
Simple and sorted no problem

Cheers
P

ian.stewart · Post by **ian.stewart** » Sat Dec 11, 2010 4:51 pm

The trouble with finding "Fuel Safe" hosing is complicated due to all the old stuff having petrol hose printed on the side, and buy your hose from a spares shop you have no method of checking its not old stock,
mostly down to the ever increasing use of more aggressive additives in the fuel attacking the composition of the rubber/plastics in the hose, Im not so sure that diaphragms and carb gaskets are immune either, nor is some of the older stainless braided immune, I have run all my fuel lines in 8mm steel bundy tubing with ollived ends to -6? fittings, and I have also converted all my fuel lines to Stainless braided teflon, rather than rubber

Ian Anderson · Post by **Ian Anderson** » Sun Dec 12, 2010 8:50 am

Problem with the braided stuff is you cannot see what the rubber / teflon etc is doing underneath the covering. The stuff still perishes under the cover and will still spring leaks

Ian

ian.stewart · Post by **ian.stewart** » Sun Dec 12, 2010 12:35 pm

Ian Anderson wrote:Problem with the braided stuff is you cannot see what the rubber / teflon etc is doing underneath the covering. The stuff still perishes under the cover and will still spring leaks

Ian

Cant agree more, but the same applies to the plain rubber too, how often do you actually get under the car and check to see if the hoses have degraded??
The SS Teflon Braided hose is aircraft spec so the hose has to be tough, BUT I would assume the spec would require the ends to be crimped rather than compression fittings

dnb · Post by **dnb** » Sun Dec 12, 2010 9:06 pm

My TVR used to have copper fuel lines, so the answer to the original question seems to be "yes".

But I didn't really like the idea, so I replaced all the fuel lines in the car with -6 and -8 200 series hose from Speedflow. It is not braided, but is sufficiently re-enforced for use in excess of 10 bar and is tolerant to alcohol based fuel.

I check the condition of the hoses every service - I have heard about far too many fires in TVRs due to dodgy fuel hose.

Ian Anderson · Post by **Ian Anderson** » Mon Dec 13, 2010 8:50 am

Expect any fuel hose to need replacing every 4 to 5 years

It's the ethanol blend that does the damage

Ian

bones · Post by **bones** » Wed Dec 15, 2010 11:09 am

Thanks for the replies all

. Another ??. Im using a jaz fuel cell which has 2 outlets , 1 for carb and 1 for nos. Should i have 2 returns aswell, and can they be just after the pumps , i need to decide on how much hose i need or braid which ever i go for. All advice welcome,

rich Also with a 347 sbf roughly 420 bhp would a 110gph holley mech fuel pump be ok just for the carb side,??

mgbv8 · Post by **mgbv8** » Wed Dec 15, 2010 7:28 pm

If the pumps are near the tank Bones, you would need to bring the return lines back from the engine bay via a tiny restrictor.
Assuming you are running a low pressure fuel system. This is the simple way. Tee off just before the fuel solenoid with your restricted return line. Dont think you need one for the carb though.

stevieturbo · Post by **stevieturbo** » Wed Dec 15, 2010 11:23 pm

More to the point, hose for what area ?

I'd reccommend copper of aluminium, mostly as parts of my Alu hardline has failed twice !!!
No idea why, but small pinhole just appeared on 2 seperate occasions.

As for rubber. Just use any proper rubber hose and it will be fine. I'd always use Gates, at least you know its quality.
It certainly wont need replaced every few years.

And 110gph Holley would feed an engine with double that sort of power.

bones · Post by **bones** » Thu Dec 16, 2010 9:00 am

Braided hose from tank in boot to metal or rubber hose underneath car to engine bay then braided to mech pump, Same from nos side aswell.

rich

stevieturbo · Post by **stevieturbo** » Thu Dec 16, 2010 12:10 pm

When you say braided, what do you mean ? Like expensive stainless crap ?

Is this all on a low pressure system ?

I see little reason to use anything other than good quality rubber hose everywhere that isnt inside the cabin.

And hardline tube, either copper, steel or other inside, or anywhere vulnerable.

Even hardline nylon tubing would be fine. Such as used in pneumatic systems, or many OE fuel lines.
It's cheap as too.

SuperV8 · Post by **SuperV8** » Thu Dec 16, 2010 1:32 pm

I think it's more important to fit it securly so it doesn't vibrate and is away from moving/hot parts rather than using expensive stainless braided stuff.
Yes this has better abrasion resistance and ultimate burst strength but it should be fitted so that it can't abrade, the burst srtength of rubber hose is way in excess of what you would need and the stainless braid makes a lovely cheese grater for any near by wires!!

Tom.