Single vs Double (fuel line, that is.)
Thread Starter
Staging Lane
Joined: Feb 2006
Posts: 50
Likes: 0
From: Sacramento, Ca
Single vs Double (fuel line, that is.) Hey,
Ready to run the fuel line, 3/8 stainless, and a friend said, " be sure to run a double line " he claims the single line with the return at the tank has a lot of problems. Any one have any experience with this?
Jim
Ready to run the fuel line, 3/8 stainless, and a friend said, " be sure to run a double line " he claims the single line with the return at the tank has a lot of problems. Any one have any experience with this?
Jim
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
I have not had a single line rail but I have not heard of anyone having any problems with them. Millions of f-bodies and vettes run them from the factory so it can`t be that big of a problem. The only thing that I have heard that would be a problem is that then if water makes it up there it is stuck there since I have read that fuel injectors cannot pass water. But even if you have the regulator on the rail there is still a chance that water could make it past it and get trapped in the rail. I have only heard of people getting a rail full of water a few times and I heard it from mechanics that were working on someones daily driver, never heard of any problems in a conversion car. The only other problem I have heard of is that the single feed rails become a slight restriction at high horsepower. I think that everyone agreed that anything below 500hp and you don`t even have to think twice about the rail, that a single line rail will be just fine at that power level. I was going to just run a single line rail with a vette regulator on my car but then when I picked my truck motor up I found out that trucks ran a dual feed fuel rail with the regulator on it......so thats what I ended up running.
i ran the single also with no problems. my regulator was mounted just above the tank in the trunk with about a three foot return. your buddy might be talking about a "true" single line with no return at the regulator where the fuel pump "dead heads" full pressure which is not a good set-up. you want to try to have a return somewhere in the system so the fuel pump isn't pushing it's max pressure all the time, if that makes any sense to you, lol.
The single setup is fine up to around 500rwhp like stated above n/a. If you run forced induction or big spray then a bigger feed line with a regulator and return from the rail is a good idea. When i did a dual intank pump system on my buddies car it had problems regulating pressure with both pumps running. Pressure would jump from 59 to 65psi.
TECH Enthusiast
Joined: Sep 2005
Posts: 618
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I'm just a little confused...brand new here.
So, it sounds like the single line you are talking about is like this: two physical fule lines, one for feed, one for return. But at the engine, the feed is a single. Is it plumbed with a T or something? The T hooking to both fuel lines, and the fuel line at the engine?
So, it sounds like the single line you are talking about is like this: two physical fule lines, one for feed, one for return. But at the engine, the feed is a single. Is it plumbed with a T or something? The T hooking to both fuel lines, and the fuel line at the engine?
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TECH Regular
Joined: Jan 2004
Posts: 426
Likes: 4
From: Austin, TX
Originally Posted by ewingr
I'm just a little confused...brand new here.
So, it sounds like the single line you are talking about is like this: two physical fule lines, one for feed, one for return. But at the engine, the feed is a single. Is it plumbed with a T or something? The T hooking to both fuel lines, and the fuel line at the engine?
So, it sounds like the single line you are talking about is like this: two physical fule lines, one for feed, one for return. But at the engine, the feed is a single. Is it plumbed with a T or something? The T hooking to both fuel lines, and the fuel line at the engine?
As far as problems, all Fbody cars since 98 and all Corvettes use the single line setup. I do not believe that GM has used the 2 line setup since 98 on any vehicle, and the single line setup seems to work just fine. If you had a real fire-breathing monster, there could be some advantage to the regulator at the fuel rail, but for the average street-driven car, The single line should work just fine.
Regards, John McGraw
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Verdad Gallardo Joined: Sep 2004
Posts: 3,148
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From: Downers Grove, IL
Originally Posted by John McGraw
As far as problems, all Fbody cars since 98 and all Corvettes use the single line setup. I do not believe that GM has used the 2 line setup since 98 on any vehicle
Now that I think about it it may have been because of tighter evaporative emissions on cars.
TECH Enthusiast
Joined: Sep 2005
Posts: 618
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The other only has one line running forward to the engine and the regulator is mounted in the rear near the tank.
I have a high volume electric Holley pump already. It's been feeding my 350 with a small blower. I'll check it's rating to see if it would work.
On the regulator: Any specific type? I presume it regulates how much pressure. I'm regulated at 7lbs at the moment. But it sounds from your description that you regulate at the return to the tank, as opposed to the egress (i.e. after the engine rather than before). Does it make any difference?
TECH Regular
Joined: Jan 2004
Posts: 426
Likes: 4
From: Austin, TX
Originally Posted by ewingr
This sounds easier, and less expensive. Sounds like a good way to go.
I have a high volume electric Holley pump already. It's been feeding my 350 with a small blower. I'll check it's rating to see if it would work.
On the regulator: Any specific type? I presume it regulates how much pressure. I'm regulated at 7lbs at the moment. But it sounds from your description that you regulate at the return to the tank, as opposed to the egress (i.e. after the engine rather than before). Does it make any difference?
I have a high volume electric Holley pump already. It's been feeding my 350 with a small blower. I'll check it's rating to see if it would work.
On the regulator: Any specific type? I presume it regulates how much pressure. I'm regulated at 7lbs at the moment. But it sounds from your description that you regulate at the return to the tank, as opposed to the egress (i.e. after the engine rather than before). Does it make any difference?
Regards, John McGraw
Thread Starter
Staging Lane
Joined: Feb 2006
Posts: 50
Likes: 0
From: Sacramento, Ca
regulator/filter I tried to get one at the local Chevy dealer and they could not find such an animal so I had to go on line. It is a ACDelco product and the # is GF822 and I paid $50.
Jim
Jim
if your chevy dealer doesnt know how tolook up a 99 vette fuel filter ..... you need to shop somewhere else. nothing against handicapped er i mean handicapable people , but i dont trust um to look up my parts. not to be mean i just want the right thing the first time. i dont like to order something (cuz the dealer never has it in stock) wait two days and THEN find out its wrong.
