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EFI fuel line ?? #2662154
06/04/19 09:26 AM
06/04/19 09:26 AM
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Stanton Offline OP
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Why do most of the EFI manufacturers recommend running rubber (or flexible) fuel line instead of rigid ??

Re: EFI fuel line ?? [Re: Stanton] #2662250
06/04/19 01:24 PM
06/04/19 01:24 PM
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moparx Offline
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that is an excellent question, as i'm not a fan of running flexi line the length of the car.
almost all of the available kits provide 20some feet of rubber [type of] hose, but i'm a believer of using that at only a few places that truly need it.
beer

Re: EFI fuel line ?? [Re: moparx] #2662286
06/04/19 03:40 PM
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I am a good guesser and here's my guess: It's consumer driven marketing. If you put the fuel line into the package you can advertise a complete system. Plus the manufacturer gets to pick the hose, suitable for its use. Then there's the hassle of stringing a line. Hardline isn't that easy for a first-timer. Sure enough Cleetus lays the hardline on an exhaust pipe or has it balancing on an edge where it wears through a lot faster than rubber. Then again it's called a "bolt-on kit" and no way is hanging hardline bolt-on.
Take your pick. Notice that none of my guesses involve technical issues. A few lawsuits can eat the profits from the entire model line.

My '07 Ford pickup has an oil pressure gauge and a pressure SWITCH. No sensor or sender. An actual decision was made at Ford to use a gauge like a warning light. As soon as the engine starts the needle goes to 60% of full scale and sits there until the engine stops running. They'd rather pay for a few lunched engines than have every Tom, Dick and Betty bringing the car back because "the oil pressure is too high or too low."

R.

Re: EFI fuel line ?? [Re: dogdays] #2662294
06/04/19 04:18 PM
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Stanton Offline OP
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As an add-on to the original question, what size lines are needed for what volume of flow. For example, a stock efi pump pushing 190 LPH capable of feeding 450 HP appears to have the same size nipple as the 450 LPH pump capable of feeding 1050 HP.

Re: EFI fuel line ?? [Re: Stanton] #2662338
06/04/19 07:18 PM
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Probably should have said "aftermarket EFI manufacturer". Pretty sure Fine Lines or whomever will roll you a set of bigger fuel hard lines you can use for most of the plumbing if you want to go that route. Heck, nickle copper is easy to work, corrosion resistant and can handle it.

Re: EFI fuel line ?? [Re: moparx] #2662346
06/04/19 07:48 PM
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Originally Posted by moparx
that is an excellent question, as i'm not a fan of running flexi line the length of the car.
almost all of the available kits provide 20some feet of rubber [type of] hose, but i'm a believer of using that at only a few places that truly need it.
beer


iagree
And will say it's a quick and dirty method for the backyard hack to install their system others have mentioned. I hard plumb for several reasons most of all it is less prone to failure. I have had several cars through the shop with the earlier braided hose carp falling apart due to it's non comparability with ethanol. We spliced one line 3 times before finally giving in and hard plumbing the system. twocents beer

Re: EFI fuel line ?? [Re: TJP] #2662386
06/04/19 09:18 PM
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Can I guess too?
I think the problem is where the hard line connects to something else. With the pressures many of the efi fuel pumps are putting out, the old rubber hose with a hose clamp can't stand the pressure very long.

I'm running a 97 Dodge efi system on my 39 Dodge truck. Originally I ran a steel line, with slightly flared ends with high pressure efi rubber hose. I clamped the hose to the line with the end of the hose past the flared part of the steel line with a pair of the efi style hose clamps. On 3 different occasions (within a month) The pump blew the hose off the steel lines. Those pumps can pump a lot of gas in a hurry. The only fix that has lasted was when I stepped up to the hard plastic lines with the special ends those plastic line require. Its been well over 6 months and the plastic line are doing well. Haven't had a fuel leak since they were installed.

My guess? The steel lines and short hoses fail too often under the high pressure the efi pumps put out. The flexible plastic lines and their connections do not fail. I would NOT recommend using steel-nickle-copper, or any other hard line with a high pressure hose and high pressure hose clamps. Use the efi designed plastic line with the correct fittings for the plastic lines. Gene

Re: EFI fuel line ?? [Re: poorboy] #2662400
06/04/19 09:41 PM
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Barbed to compression fitting and EFI clamps do the trick every time. You cannot just put a slight flare on the end of the hard line, it will not hold as you found out.

Hardline and hoses contain thousands of pounds of pressure in the brake lines, less than 100lbs fuel pressure is nothing.

You can even get flared to barb fitting so you can flare your hardlines just like brake lines and properly attach the EFI hose to the barbed end.

Re: EFI fuel line ?? [Re: Sniper] #2662435
06/04/19 11:17 PM
06/04/19 11:17 PM
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Stanton Offline OP
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Quote
Pretty sure Fine Lines or whomever will roll you a set of bigger fuel hard lines


There is nothing on Fine Lines web site which indicates they make any lines other that the shorties from the master cylinder.

I'll keep searching for another manufacturer.

Re: EFI fuel line ?? [Re: Stanton] #2662484
06/05/19 07:05 AM
06/05/19 07:05 AM
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Every remotely modern semi truck headed down the road has nylon braided fuel and oil lines on it that live with absolutely no problems over hundreds of thousands of miles. Yes, diesel is different than gasoline, but today's rubber lines are all ethanol-rated.

Hardlines are fine if that is what you want to run, but they are by far not a requirement for a successful, long-lasting system.


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Re: EFI fuel line ?? [Re: GoodysGotaCuda] #2662511
06/05/19 08:34 AM
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Originally Posted by GoodysGotaCuda
Every remotely modern semi truck headed down the road has nylon braided fuel and oil lines on it that live with absolutely no problems over hundreds of thousands of miles. Yes, diesel is different than gasoline, but today's rubber lines are all ethanol-rated.

Hardlines are fine if that is what you want to run, but they are by far not a requirement for a successful, long-lasting system.


Assuming you know how to properly install plastic/nylon lines and have the appropriate tools.

Re: EFI fuel line ?? [Re: poorboy] #2662797
06/05/19 07:54 PM
06/05/19 07:54 PM
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Originally Posted by poorboy
Can I guess too?
I think the problem is where the hard line connects to something else. With the pressures many of the efi fuel pumps are putting out, the old rubber hose with a hose clamp can't stand the pressure very long.

I'm running a 97 Dodge efi system on my 39 Dodge truck. Originally I ran a steel line, with slightly flared ends with high pressure efi rubber hose. I clamped the hose to the line with the end of the hose past the flared part of the steel line with a pair of the efi style hose clamps. On 3 different occasions (within a month) The pump blew the hose off the steel lines. Those pumps can pump a lot of gas in a hurry. The only fix that has lasted was when I stepped up to the hard plastic lines with the special ends those plastic line require. Its been well over 6 months and the plastic line are doing well. Haven't had a fuel leak since they were installed.

My guess? The steel lines and short hoses fail too often under the high pressure the efi pumps put out. The flexible plastic lines and their connections do not fail. I would NOT recommend using steel-nickle-copper, or any other hard line with a high pressure hose and high pressure hose clamps. Use the efi designed plastic line with the correct fittings for the plastic lines. Gene


That is why you flare the steel line instead of sticking with the bulb/beaded end. 37 degree single flare JIC will work for AN fittings.


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Re: EFI fuel line ?? [Re: astjp2] #2662799
06/05/19 07:56 PM
06/05/19 07:56 PM
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my guesses:
1. people are lazy, its easy to run a hose and install a few clamps
2. people dont have the skills to work with hard line
3. I will fall back to number 1 which eliminates number 2


1941 Taylorcraft
1968 Charger
1994 Wrangler
1998 Wrangler
2008 Kia Rio
2017 Jetta

I didn't do 4 years and 9 months of Graduate School to be called Mister!
Re: EFI fuel line ?? [Re: Stanton] #2663666
06/08/19 12:02 AM
06/08/19 12:02 AM
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I think it is mostly that the flexible lines are easier and cheaper.
With the hard lines, you still need flexible hose at each end which is two more hose fittings per flexible line and two more hard line fittings per line, so with a return type system, and extra 4 hose fittings, and 4-hardline fittings.
In addition to that, it would be even more expensive for them to supply new hard lines for all the different vehicles. Most cars these aftermarket EFI systems are going on only have 5/16" hard line, and no return line, and on our old cars the old steel lines are likely full of rust and other trash that will get into the injectors. I like new stainless 3/8" hard lines, but it adds several hundred dollars more to go that route.

Re: EFI fuel line ?? [Re: 451Mopar] #2663667
06/08/19 12:05 AM
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Stainless can be difficult to flare without cracking for most if you DIY. Nickle copper is fine for this, flares easy, forms easy, doesn't rust.

Re: EFI fuel line ?? [Re: Sniper] #2663743
06/08/19 09:40 AM
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moparx Offline
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stainless is nice, but i'm not into shiny stuff. nickel/copper works for me.
beer

Re: EFI fuel line ?? [Re: moparx] #2663768
06/08/19 12:08 PM
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Wrong post

Last edited by BDW; 06/09/19 07:30 AM.
Re: EFI fuel line ?? [Re: moparx] #2663909
06/09/19 02:53 AM
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You guys are right about the NickleCopper. Good stuff to work with.







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