Do stock fuel lines have hp limit?
12-25-2012, 08:47 PM
#1
Do stock fuel lines have hp limit? Currently trying to find out what all I need to put fuel system together. Going from LT1 to turbo LQ4. From what I understand, my stock LT1 fuel lines are 3/8" feed line and 5/16" return.
First question is, are those big enough? I'm assuming they are smaller than LS fuel lines.
On the Aeromotive page they have a hp calculator and it says to have AN-10 feed line all the way to FPR, and an AN-6 return line. I'm looking at an conversion chart and it says 3/8" is an AN-6. So does this mean my feed line is too small?
Also on the page they say use either a 13101 or 13109 FPR. The 13101 has ORB-10 feed and, ORB-6 return. The 13109 has an ORB-6 feed and ORB-6 return. Why would they recommend the 13109 if it was an ORB-6 feed but they just said to use an AN-10 feed?
. I'm not completely sure what AN and ORB is, just assuming its line size, but am I missing something?
First question is, are those big enough? I'm assuming they are smaller than LS fuel lines.
On the Aeromotive page they have a hp calculator and it says to have AN-10 feed line all the way to FPR, and an AN-6 return line. I'm looking at an conversion chart and it says 3/8" is an AN-6. So does this mean my feed line is too small?
Also on the page they say use either a 13101 or 13109 FPR. The 13101 has ORB-10 feed and, ORB-6 return. The 13109 has an ORB-6 feed and ORB-6 return. Why would they recommend the 13109 if it was an ORB-6 feed but they just said to use an AN-10 feed?
. I'm not completely sure what AN and ORB is, just assuming its line size, but am I missing something?
12-25-2012, 09:42 PM
#2
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^ IIRC, the LS feed line is 5/16".. Not sure. Forgot what sizes I bought for my build.
But for what you're doing, a -6 would be too small for a feed line. I think -8 is closer to 3/8" so you should be fine there. I think a -10 would be a little big, but I'm not real sure. In your case, I would imagine max effort, I'd try to stay -10 ORB feed which can be stepped to a -10 and under. See if you can match your feed and return. -8 and -8, for instance.
AN ORB = O-Ring Boss fitting. Boss fittings thread into a block. Almost always have an o-ring for the seal. Don't trust pipe thread.
JIC fittings are the -8 (example) fittings. That's the taper that makes the seal.
FF would be a flat face with an o-ring, but those are mainly for hydraulic fittings and not for fuel.
But for what you're doing, a -6 would be too small for a feed line. I think -8 is closer to 3/8" so you should be fine there. I think a -10 would be a little big, but I'm not real sure. In your case, I would imagine max effort, I'd try to stay -10 ORB feed which can be stepped to a -10 and under. See if you can match your feed and return. -8 and -8, for instance.
AN ORB = O-Ring Boss fitting. Boss fittings thread into a block. Almost always have an o-ring for the seal. Don't trust pipe thread.
JIC fittings are the -8 (example) fittings. That's the taper that makes the seal.
FF would be a flat face with an o-ring, but those are mainly for hydraulic fittings and not for fuel.
Last edited by bayer-z28; 12-25-2012 at 10:16 PM.
12-25-2012, 10:03 PM
#3
"Turbo LQ4" could really mean a lot of things - it could be mild or really aggressive. If you're doing a budget-minded build with stock internal and keeping the HP reasonable, I think the 3/8"/AN6 line would be fine with the appropriate fuel pump. If you're doing a really expensive and aggressive build, you might need to go up in size.
Tell us a little more about your build!
Tell us a little more about your build!
12-25-2012, 10:05 PM
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^ IIRC, the LS feed line is 5/16".. Not sure. Forgot what sizes I bought for my build.
But for what you're doing, a -6 would be too small for a feed line. I think -8 is closer to 3/8" so you should be fine there. I think a -10 would be a little big, but I'm not real sure. In your case, I would imagine max effort, I'd try to stay -10 ORB feed which can be stepped to a -10 and under. See if you can match your feed and return. -8 and -8, for instance.
AN ORB = Anodized O-Ring Boss fitting. Boss fittings thread into a block. Almost always have an o-ring for the seal. Don't trust pipe thread.
JIC fittings are the -8 (example) fittings. That's the taper that makes the seal.
FF would be a flat face with an o-ring, but those are mainly for hydraulic fittings and not for fuel.
But for what you're doing, a -6 would be too small for a feed line. I think -8 is closer to 3/8" so you should be fine there. I think a -10 would be a little big, but I'm not real sure. In your case, I would imagine max effort, I'd try to stay -10 ORB feed which can be stepped to a -10 and under. See if you can match your feed and return. -8 and -8, for instance.
AN ORB = Anodized O-Ring Boss fitting. Boss fittings thread into a block. Almost always have an o-ring for the seal. Don't trust pipe thread.
JIC fittings are the -8 (example) fittings. That's the taper that makes the seal.
FF would be a flat face with an o-ring, but those are mainly for hydraulic fittings and not for fuel.
-6 = 3/8"
-5 = 5/16"
JIC is very general. which spec?
most GM vehicles i've messed with came with 3/8" feed and 5/16" return lines. i'm pretty sure even the zr1 has a 3/8" feed
op, what's your power goal and how low will your fuel pressure be that -10 is required?
12-25-2012, 10:11 PM
#6
Tell me if I have this straight. So an AN-10 fitting and AN-6 fitting doesnt mean the line is bigger, its the size of the fitting? They say have an AN-10 from pump to filter, AN-10 from filter to Y block, AN-8 from Y block to fuel rails, AN-8 from fuel rails to FPR, and AN-6 from FPR to return.
So when they give these AN number thats not the size of the line thats the size or taper of the fitting?
And if I need to get larger fuel lines where would I get these? From tank all the way to rails.
So when they give these AN number thats not the size of the line thats the size or taper of the fitting?
And if I need to get larger fuel lines where would I get these? From tank all the way to rails.
12-25-2012, 10:15 PM
#7
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^ The taper is all the same across what we have access to. -10 is larger, -8 is smaller than that. Bigger the number, the bigger the ID of the hose.
-8 fittings goes with a -8 hose
-10 fitting goes with a -10 hose. etc etc..
-8 fittings goes with a -8 hose
-10 fitting goes with a -10 hose. etc etc..
Last edited by bayer-z28; 12-25-2012 at 10:20 PM.
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12-25-2012, 10:18 PM
#8
Whoa ok, three more posts since I typed last one. Thanks, I'll try to catch up.
So I'm not going completely stock, hp will be around 600-650 rwhp. But eventually I'll forge and go for 800-900 so I'd like to get it all done and right the first time, no matter the cost.
I plan on using the A1000 fuel pump. They say thats in the 1000hp chart.
So the LS cars use a 3/8" feed line also? I would imagine I would be fine then for up to 800rwhp then right?
Would the Y block they talk about be used in my setup?
Sorry for all the questions, both LS and FI is both new to me but I'm learning
So I'm not going completely stock, hp will be around 600-650 rwhp. But eventually I'll forge and go for 800-900 so I'd like to get it all done and right the first time, no matter the cost.
I plan on using the A1000 fuel pump. They say thats in the 1000hp chart.
So the LS cars use a 3/8" feed line also? I would imagine I would be fine then for up to 800rwhp then right?
Would the Y block they talk about be used in my setup?
Sorry for all the questions, both LS and FI is both new to me but I'm learning
12-25-2012, 11:42 PM
#11
A 5/8" fuel feed line is huge and probably unnecessary for you. I am thinking that 1/2" will get you to 1,000rwhp. There are plenty of +600rwhp cars out there running 3/8" fuel lines.
The jump from 3/8" to 1/2" is pretty big. Roughly speaking, a 1/2" line will flow about 150% of a 3/8" line.
The jump from 3/8" to 1/2" is pretty big. Roughly speaking, a 1/2" line will flow about 150% of a 3/8" line.
12-25-2012, 11:59 PM
#12
I guess that answers all my questions. Instead of worrying about it now I'll just keep the factory lines. Just three more questions.
1. Do you know the limits, about how far past 600. If its 700 I'm golden for now.
2. So if I'm using the factory lines, not going past 650hp, which FPR would you use. I'm assuming the aeromotive 13109. It uses ORB-6 feed, ORB-6 return, and operates at 40-75psi.
3. There are two feed ports on the side and one return on the bottom. Why is there two feed. Would I use both or just one.
1. Do you know the limits, about how far past 600. If its 700 I'm golden for now.
2. So if I'm using the factory lines, not going past 650hp, which FPR would you use. I'm assuming the aeromotive 13109. It uses ORB-6 feed, ORB-6 return, and operates at 40-75psi.
3. There are two feed ports on the side and one return on the bottom. Why is there two feed. Would I use both or just one.
12-26-2012, 12:33 AM
#13
Let me try to clarify something.... lines do not typically have a HP limit. Given enough available pressure, you can get a lot of flow through a small line.
What you have to consider is the entire system. First you determine the power level of the engine, then size the injectors & pump so they flow the appropriate amount of fuel at a pressure they can both operate at. Also factor in the boost reference.
For example you cannot size a set of injectors for 58psi & then boost reference 20psi boost & but a pump that is rated for less than 78psi. This is where the line size comes into play. How much safety factor is left between the pump flow/pressure & the injector flow/pressure.
If you are close with the 2, then your line has to have minimal restriction.
If your pump has 20psi of extra capacity, then the line can be smaller.
It is all about matching the system to the need.
I try to go with -8 if buying new lines as the cost is minimal over a -6.
If you have a -6 already, I would not worry about it unless you are planning well over 750rwhp. Then it is a function of the pump being able to overcome the line restriction. I have seen -6 support over 1000rwhp, but I do not recommend a -6 for 1000rwhp if you are buying new parts. There is a significant difference between designing a proper system & making due with what you have.
What you have to consider is the entire system. First you determine the power level of the engine, then size the injectors & pump so they flow the appropriate amount of fuel at a pressure they can both operate at. Also factor in the boost reference.
For example you cannot size a set of injectors for 58psi & then boost reference 20psi boost & but a pump that is rated for less than 78psi. This is where the line size comes into play. How much safety factor is left between the pump flow/pressure & the injector flow/pressure.
If you are close with the 2, then your line has to have minimal restriction.
If your pump has 20psi of extra capacity, then the line can be smaller.
It is all about matching the system to the need.
I try to go with -8 if buying new lines as the cost is minimal over a -6.
If you have a -6 already, I would not worry about it unless you are planning well over 750rwhp. Then it is a function of the pump being able to overcome the line restriction. I have seen -6 support over 1000rwhp, but I do not recommend a -6 for 1000rwhp if you are buying new parts. There is a significant difference between designing a proper system & making due with what you have.
