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Fuel lines, hard or soft. What is the general sense on fuel lines?

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Old Apr 28, 2009 | 09:51 AM
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Fuel lines, hard or soft. What is the general sense on fuel lines?

What is the general sense on fuel lines?

In my case a mild V8 is the application. standard 7-9psi carb system.
So high pressure is never a question for me. Others may car about hgh psi.

What are folks running over stock. [say stock lines are all bad]

I believe 3/8" is good up to around 500hp

What kind of line?

soft
rubber
steel braided rubber.
steel braided teflon.
teflon braided rubber.

Solid
Copper.
Aluminum.
Galvanized Zinc.
Stainless steel.
Other

What kind of fittings.

AN - aluminum
NPT - brass

hose barbs n clamps?
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Old Apr 28, 2009 | 10:02 AM
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Car: 1985 Z28
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Re: Fuel lines, hard or soft. What is the general sense on fuel lines?

Any kind of metal would work fine. As far as soft, I'd go metal braided teflon. AN for fittings, but thats my personal opinion.
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Old Apr 28, 2009 | 06:35 PM
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From: NWOhioToledoArea
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Re: Fuel lines, hard or soft. What is the general sense on fuel lines?

what about size is 3/8" enough?

I dont see any bigger hard lines.
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Old Apr 29, 2009 | 09:09 AM
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Car: '91 S10 Blazer
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Re: Fuel lines, hard or soft. What is the general sense on fuel lines?

3/8 is plenty big for a close to stock application.

As for material - try to use hard line whenever possible. Some racing classes won't allow more than (12"?) of total rubber line.

DON'T use copper! Very prone to fatigue cracking. It's great in houses, but they don't usually drive down the road and vibrate and heat cycle.

Stainless is hard to bend without cracking (depending on the exact type).

As for the 'rubber' lines, just make sure that whatever you use says 'fuel line' on it. Doesn't matter if it's EFI hose or not in your case. But EFI hose is usually thicker jacketed and stronger.

Fittings are fittings. Use what your budget allows. Just be kind to the next person to work on your setup.... use all the same ones....
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Old Apr 29, 2009 | 12:56 PM
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Re: Fuel lines, hard or soft. What is the general sense on fuel lines?

Thinking of going with aluminum as summit is having some nice sales on it.

Never used aluminum tubing like that and only worry about the softness?

Even with a tubing bender is it gonna kink easy and what about making the flares? I can see it splitting when the flare is made, copper does sometimes.

Did find some 1/2" tubing nad its cheaper then 3/8"
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Old Apr 29, 2009 | 01:02 PM
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From: boise, ID
Car: 91 B4C "police special service"
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Re: Fuel lines, hard or soft. What is the general sense on fuel lines?

just for a tid bit of info....if you plan to race the car at a dragstrip...NHRA rules (which all tracks are supposed to follow) dictate that you can not have more than 12" of rubber fuel line on a vehicle. Metal braided line counts as metal line. Some tracks don't check....but getting braided line would be my recommendation....
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Old Apr 29, 2009 | 01:20 PM
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From: NWOhioToledoArea
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Re: Fuel lines, hard or soft. What is the general sense on fuel lines?

braided hose would be but cost so much more, I can get the solid line for 1/3 the price and I don't need to make allot of bends. Long straight shot mostly.

I would be using some braided on the small section at the FP and gastank so it has flex.
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Old Apr 29, 2009 | 04:43 PM
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Re: Fuel lines, hard or soft. What is the general sense on fuel lines?

That would be ideal, braided is usually only the last foot or so of the total span

BTW the cost of braided hose is greatly outweighed by the cost of fittings on the ends so length isnt a huge issue
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Old Apr 29, 2009 | 11:21 PM
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Re: Fuel lines, hard or soft. What is the general sense on fuel lines?

Originally Posted by Gumby
Thinking of going with aluminum as summit is having some nice sales on it.

Never used aluminum tubing like that and only worry about the softness?

Even with a tubing bender is it gonna kink easy and what about making the flares? I can see it splitting when the flare is made, copper does sometimes.

Did find some 1/2" tubing nad its cheaper then 3/8"

I'd just stick to the regular mild steel tubing. It's easy to form without being damaged, it's easier to flare (if you go that route) without being damaged from cracking, and less easily damaged from 'road rash' such as rocks, etc. Seeing a trend?

If the 1/2 is WAY cheaper, even factoring in the fittings, hoses, etc - go for it. Just remember that you're only as strong as your weakest link. So if you have to reduce to 3/8 at the carb.... it was all pretty much pointless!

And I think as mentioned... the odds of your NEEDING the flow of 1/2" is probably pretty minimal.
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Old Apr 30, 2009 | 12:16 AM
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From: NWOhioToledoArea
Car: 86-FireBird
Engine: -MPFI
Transmission: T5
Axle/Gears: 3:42
Re: Fuel lines, hard or soft. What is the general sense on fuel lines?

Id be cheaping out on fittings In afraid, not using any of that AN stuff after pricing it all.

Regular brass fittings is in order, plus easy to get local as needed.

Yea Im back to using 3/8" steel line as after looking at all Ill need, ill be steping down the sizes all over the place.

Only $150-200 150GPH electric fuel pump have a 3/8" fitting.

All the rest are 1/8" or 1/4" .
All the Mr gasket ones in my needs range are 1/8", knock off off brand is 1/4"

FP regulators are 3/8" though.

Fuel filter 3/8"


Gonna use a 30 GPH 2-4 PSI electric pump as a pusher in the rear to feed the Mech stock pump on the block. Regulate with a 1/4" return and a gauge.
Id rather end up with to much to then to less flow.

Last edited by Gumby; Apr 30, 2009 at 12:22 AM.
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