Time for new fuel system. Ideas?
Thread Starter
Race Director
Joined: Mar 1999
Posts: 10,258
Likes: 1
From: Calif.
Time for new fuel system. Ideas?
The old system is poop. Not enough flow. Want to upgrade to something that will be more suitable for this engine. I'm very new to the AN thing, though, but what I'd like to do is something along these lines (pardon the pun):
3/8" AN bulkhead fitting at the bottom rear of the tank. 3/8" stainless hose to a 130-150 gph electric pump mounted "somewhere" in the right rear wheel well area.
About 1 foot of 3/8" stainless hose going to a 3/8" aluminum hard line that runs along the inside of the frame rail and up to a 3-port regulator "somewhere" on the right side of engine compartment.
3/8" stainless with an in-line filter into a nice AN style fuel log for the Holley 4150. Pressure gauge mounted there.
From the other (return) port on the regulator I'd like to run about a foot of 3/8" stainless hose into a 3/8" aluminum hard line that runs along the inside of the frame rail and into a 3/8" bulkhead fitting somewhere in the top of the tank.
All this AN-to-flare-to-pipe-to-whatever adapter stuff makes my head hurt. First of all, is this a plausible sounding system? Second, can somebody point me to a URL that has a good rudimentary walk-through of all this stuff? Any general guidance and/or suggestions would be appreciated greatly also.
Thanks.
[Modified by The Dude, 9:00 PM 1/21/2002]
3/8" AN bulkhead fitting at the bottom rear of the tank. 3/8" stainless hose to a 130-150 gph electric pump mounted "somewhere" in the right rear wheel well area.
About 1 foot of 3/8" stainless hose going to a 3/8" aluminum hard line that runs along the inside of the frame rail and up to a 3-port regulator "somewhere" on the right side of engine compartment.
3/8" stainless with an in-line filter into a nice AN style fuel log for the Holley 4150. Pressure gauge mounted there.
From the other (return) port on the regulator I'd like to run about a foot of 3/8" stainless hose into a 3/8" aluminum hard line that runs along the inside of the frame rail and into a 3/8" bulkhead fitting somewhere in the top of the tank.
All this AN-to-flare-to-pipe-to-whatever adapter stuff makes my head hurt. First of all, is this a plausible sounding system? Second, can somebody point me to a URL that has a good rudimentary walk-through of all this stuff? Any general guidance and/or suggestions would be appreciated greatly also.
Thanks.
[Modified by The Dude, 9:00 PM 1/21/2002]
Melting Slicks
Joined: Dec 2000
Posts: 2,041
Likes: 0
From: Wichita, KS
Re: Time for new fuel system. Ideas? (The Dude)
I think that you'll find that the automotive pipe fittings flow better than AN fittings for the same size tube.
AN fittings use a 37 degree single flare, while auto. pipe uses a 45 degree double flare. AN fittings are not sized for a double 37 degree flare. When you connect the fitting there will not be enough thread engagement for a proper torque.
Double flares are a pain to make correctly.
AN fittings are anodized to prevent dissimmiler metal corrosion when used with steel lines. The anodizing will wear off. Guess what happens then.
So why do all the racers use AN? Race origanizations require braided hose and the AN fittings are easier to locate for braided line. Remember, you need larger AN for equal flow so you step up to -8 AN to equal 3/8 flow but now the fittings don't match the pipe size so you step up to 7/16 pipe. Now you're back to giving up flow. See the cycle. You stay with one or the other throughout the system.
While you're planning all of this, do your engine a favor and use a large volume filter, like a fram, in the system. They only cause 1/2 pound of pressure drop in the system when clean and could save a lot of grief.
AN fittings use a 37 degree single flare, while auto. pipe uses a 45 degree double flare. AN fittings are not sized for a double 37 degree flare. When you connect the fitting there will not be enough thread engagement for a proper torque.
Double flares are a pain to make correctly.
AN fittings are anodized to prevent dissimmiler metal corrosion when used with steel lines. The anodizing will wear off. Guess what happens then.
So why do all the racers use AN? Race origanizations require braided hose and the AN fittings are easier to locate for braided line. Remember, you need larger AN for equal flow so you step up to -8 AN to equal 3/8 flow but now the fittings don't match the pipe size so you step up to 7/16 pipe. Now you're back to giving up flow. See the cycle. You stay with one or the other throughout the system.
While you're planning all of this, do your engine a favor and use a large volume filter, like a fram, in the system. They only cause 1/2 pound of pressure drop in the system when clean and could save a lot of grief.
