fuel lines

DTanklage

DTanklage

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Jan 2, 2009
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i know that most think bigger is always better

was wondering what is the most hp anyone has made with -6 going into the pump? (3/8 id)

am gonna run a -8 return (cuz the tank is already set up for that)

so i need to keep supply one size smaller (-6)

would be nice to run -8 or -10 into the pump but that would require -10 or -12 return and i got no where to put a line that big into the stock tank

pretty sure -6 will be fine for what i am doing was just curious what kind of numbers have been achieved with this sort of system

thanks, don
 
AD150 use 1/2 or -8 feed, return and inj pump feed. If running a sump, i would run a -10 or -12 to feed the pump then -8 to the pump and a -8 return to the tank I think fass uses all -6 3/8 lines. Tim
 
I pretty sure those who made 1000hp and more didn't have anymore than 1/2 ( -8 ) lines. You'd have to be using a lotttt of fuel to require much bigger.
 
ILLINOISRAM said:
-8 to the pump and a -8 return to the tank

Tim
Click to expand...

thats not the right way to do it tim

return is always supposed to be larger than the feed

and further the tank is from the regulator - the larger the return is supposed to be


like i said, for what i am doing i am pretty sure -6 is gonna be fine...

but i am curious what kind of hp numbers have been made with a -6 feed

if all the fuel that came thru the feed went into the motor it would be different but a lot is returned to the tank

thats my only concern

thanks, don
 
what do you need to hook up some AN -6 and -8 lines to the tank? is that draw straw thing what I need?
 
my vp truck has done 700 on 3/8 lines. my brothers 12 valve is probably around 750 right now on 3/8 line. No problems with either.
 
thnx rockjeep

lance, a draw straw or a sump

either or those or something like the abomination in the middle of that 20 dollar pile of parts n hose

: )

RegnPlumbing016.jpg


ps - thank you mesa hose

i love you brooks
 
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DTanklage said:
thats not the right way to do it tim

return is always supposed to be larger than the feed

and further the tank is from the regulator - the larger the return is supposed to be
Click to expand...

Really? I guess you had better explain that one to the automotive manufacturers then. Every car I've worked on has a smaller return line than the feed.

You can't return more fuel than you feed to the pump so at worst you would need the same size line as the feed IMHO. Smaller is likely just fine since you're using some of the fuel you're pumping anyway.

I'm running a 1/2" feed and a 3/8" return FWIW.
 
maybe they didnt mind some pressure building up in the return?

when you are using the regulator as a bypass you dont want that

if it is present the reg cant hold the pressure steady

i build a lot of nitrous systems (and nitrous fuel systems) so i am pretty sure about it

i dont have much experience with the boost reference stuff but i believe that part of the operation would be the same

hey, maybe i am wrong. was wrong about where to plumb the return when using the boost ref earlier

if so - i appologize

almost 50 and still learning

unfortunately i am forgetting too...

lol - if you cant laugh at yourself you might as well quit!
 
sorry dude, this time i am right

with the pump i am running if my return is 0-5 feet long it can be -8

if its 6-10 foot long it should be -10

and if its 11-15 feet long it should be -12

thats according to the aeromotive chart

not me talking out the side of my neck
 
I've never bothered to check fuel pressures on the return lines of anything I've worked on. I might have to try that at some point...

I have worked on a few cars that have had pressure regulation issues like you are talking about, but they were typically vehicles that the owners put a high volume pump on and the stock pressure regulator couldn't bypass enough fuel to keep it under control.

Back on topic, I would expect that a 3/8" feed line would be sufficient for most applications.

EDIT: Your last post is interesting considering that the feed ports on the regulators I have worked with are usually bigger than the return line port. The regulator on my truck has two -10 feed ports and one -6 return port. If the manufacturers really wanted a bigger return than a feed I would think they would build their parts that way.

It looks like I need to do some more reading on this subject...
 
DTanklage said:
thats not the right way to do it tim

return is always supposed to be larger than the feed

and further the tank is from the regulator - the larger the return is supposed to be thanks, don
Click to expand...


Im not sure here but why is the stock feed on our trucks a 3/8 steel line and the return is a 5/16 steel line.

I dont know if we are on the same page with this. My AD150 has a built in return that uses a 1/2 line that splices in to the fillerneck. Plus i ran a 3/8 return line from the overflow valve, t'ed in a 3/8 line from the back of the 24v head, then ran that back to the tank. The ppump is feed with a 1/2 inch line straight from the AD150. So if the return is allways supossed to be bigger than the feed, AD and FASS i guess dont know what they are doing.:what:

If i understand, you are running a aeromotive A1000? pump which does not have a built in return. So you have your return from the ppump. Then i could see uping the size of the return line but i still not sure i agree with the bigger part.

Tim
 
Umm.... you can run whatever size lines you want on the feed and return. The normal way to run is to have a larger feed line than return, every auto maker does this, and every hotrodder/car builder I know or have talked to does it this way. I have never personally met anyone that has said the return needs to be bigger than the feed although it has been discussed before.

What is the reasoning behind needing a bigger return than a feed? You cant return more fuel than you send. I think 1/2" feed and 3/8" return will handle a very large amount of power, maybe if you go over 1000rwhp I would consider going 5/8" feed and 1/2" return.

If you still dont believe anyone here I would call aeromotive and let them tell you to make your feed larger than the return since that is how they make their kits.
 
I agree totally with running an equal or larger size return because of the style pumps that aeromotive builds. You need the flow to keep cool fuel running through the pump.

This also coinsides with the hydraulic training I have for applications where flow is very closely controlled.

On The other hand, This isn't how I intend to plumb mine because I want the pressure to remain fairly high ahead of the restriction.

The most accurate way to control a hydraulic circuit is to regulate return flow.

Kyle
 
does anyone know what size fittings are on the 12v stock lift pump and filter block? what kind of adapters do I need for running some AN hoses? and on the P-pump also? feed and return?
 
wow, woke up to everyone jumping down my throat

think about it for a minute, okay? with an open mind...

think about how it all works...

i do not have a regulator in my pump anymore, so yea, it is kinda like a a-1000, not a ad or fass. how long is the return line in a AD? less than 5 feet, from reg (in pump) to tank. my deal the reg is up by the motor (after the ip) so my return lines have to be a lot longer than that. take a foot of -6 hose and try to blow thru it. take 15 feet of it and try it again, makes restriction, right? well, if your return line is making restriction than that restriction is doing part of the regulating (normally the job of the spring on the other side of the diaphram). the fuel pressure is supposed to lift the diaphram and what is not needed dumps out the bottom of the reg. if the return line is a restriction (pressure) than it is doing part of the springs job and the spring wont be able to keep the pressure steady

go to the pits and look at a prostock car

or go to aeromotives site and read a little

good morning

don
 
Lance said:
does anyone know what size fittings are on the 12v stock lift pump and filter block? what kind of adapters do I need for running some AN hoses? and on the P-pump also? feed and return?
Click to expand...

metric 14mm and 18mm

thread pitch for both the big n small is 1.5

only thing i am not sure about is the lift pump. it has those compression fittings for flared tubing

don

ps - there is not a lot of room where the return comes out of the p-7100 so you will have to get creative or use a metric AN banjo fitting
 
carcrafter22 said:
call aeromotive and let them tell you to make your feed larger than the return since that is how they make their kits.
Click to expand...

what kits are you referring to?

i have built a lot of nitrous fuel systems (not from kits but from scratch). with nitrous it is very important to keep the pressure steady, if the pressure creaps you lift a ring land cuz it ran fat, if the pressure drops you melt a piston cuz it ran lean. (gassers, not diesel)

for what we are doing it probably dont matter 5 psi +/- but truely, the right way to return fuel to the tank behind a bypass reg is in a large line. and the longer the line the larger it has to be for the regulator to function correctly

can you picture how it works?

don

ps - the info i posted above (the req retun sizes) IS from the aeromotive site. hard to believe no one believes me (cept the guy with hydrolic training)
 
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