AN Adapters For Fuel Feed And Return. Also Fuel Filter To Use?

B

Blown&Injected

Active Member
Joined
May 31, 2001
It seems to have been a long time since this issue has been discussed. I am thinking about going with -8 feed and -6 return. I currently have an internal pump and an external pump with -6 line going from the external pump to the stock filter, then stock stuff after but that stuff is rusted and leaking.

The reason I am looking at a different filter is that the -6 to O-ring adapter used to adapt the stock filter chokes the line down to less than 1/4" on the O-ring side!!!

I have read about cars running into the 9's with the stock fuel lines but if going with all new stuff, the volume from the 1/2 lines may just make it all work easier. Besides, I never liked the way the fuel line runs right up on the block and no more rust.

1) What AN adapter is needed on the fuel rail?
2) What adapter is needed on the fuel pressure regulator?
3) Any filter recommendations to get away from the adapter that chokes down to less than 1/4" on the feed side?

I do not have to keep the external pump if you guys have some better ideas - I have always wondered how effective it is to have two different pumps in line. maybe just weld a steel AN adapter to the steel line from the tank and bag the external pump? How fast are people going with just a single 340 in the tank?

Thanks
:)
 
PhilM said:
Russell makes the fittings for the GM o-ring conversion... check out PNs: 648060 & 648070
http://www.russellperformance.com/auto/adapt/adapt_fit_fuel-3-27.shtml

As for the filter, im running a System 1 "pro street" filter Jegs PN: 888-20140. Very nice unit, with good stainless filter element that is reuseable. I'd imagine most of the billet filters are about all the same tho.

Phil
Click to expand...

Those are all -6 and guess what not big enough for what was used in the old days (Or at least on my car) it was all -8 and I have yet to find the damn fitting that fits -8 line to filter as the one on my car is striped!!!!!!! :eek:
Russels dosnt make it already called them and Areoquipe said they used to but no more :( Just not enough demand for them. So I am thinking aftermarket fuel filter and -8 line to the tank :)
God's only know when Ill get to that one :eek:
 
Blown&Injected said:
The reason I am looking at a different filter is that the -6 to O-ring adapter used to adapt the stock filter chokes the line down to less than 1/4" on the O-ring side!!!

:)
Click to expand...

I just ordered those fittings from PTE. Then I found an old fitting I had gotton a while back. When I compaired to two, the PTE fitting had a much smaller bore and o-ring then the other fitting I already had. I used the larger bore fitting because the o-ring matched the fuel filter better. The point is, there is more then one fitting floating around.
 
Cool man!

Thanks for the ideas. I was/am thinking about welding a fitting on the fuel rail and on the feed line out of the tank.

Anybody useing the aluminum tubing to make the run under the car and braided between the tank/filter and the front of the frame to fuel rail?
 
I used -8 and -6 braided hoses all the way from the rail to the tank. Used all Earl's stuff and adapters for the tank line and rail from John Butler (JB powdercoating I think).
I have his phone number so PM or email me if you want it. The adapters work great and do not leak.
They were cheap but all that braided line sure isn't!
I used an Earl's inline filter.
 
Blown&Injected said:
Anybody useing the aluminum tubing to make the run under the car and braided between the tank/filter and the front of the frame to fuel rail?
Click to expand...


Doubt it. Aluminum can fatigue caused by movement and vibration. And it would also just be a pain to work with trying to route it safely from front to back. Use pushlock, braided, etc.

And if you are upgrading line size, it might be a good idea to upgrade to a good high flow aftermarket style filter as well.
 
The down side to the adapters is that you are still stuck with the small I.D. of the Saginaw style fitting. The fuel rails are plenty large, but the restriction will now be the inlet at the rail if you use the adapters. Best bet is to cut the stock "nut" with the threads off the stock rail and get a steel male -8 or what ever size AN you are using and welding it right to the rail. That way you will eliminate the restriction. There is no sense in adding large lines if you are reducing them down to approx 5/16" where the fuel passes through the part of the fitting that has the o-ring.
It should also be noted that you could play hell with the fuel pressure regulator because of where the outlet is. Best bet is to keep part of the stock steel hardline that goes into it and clamp the hose to it. A budget set up could be using the stock feed lines as the return as the stock return lines are horrible in the rear of the vehicle where they step from 5/16" to 1/4" over the axle. I personally as well as some others on here have had the stock return line plug in this location.
 
GNVAIR said:
The down side to the adapters is that you are still stuck with the small I.D. of the Saginaw style fitting. The fuel rails are plenty large, but the restriction will now be the inlet at the rail if you use the adapters. Best bet is to cut the stock "nut" with the threads off the stock rail and get a steel male -8 or what ever size AN you are using and welding it right to the rail. That way you will eliminate the restriction. There is no sense in adding large lines if you are reducing them down to approx 5/16" where the fuel passes through the part of the fitting that has the o-ring.
Click to expand...

Exactly.


GNVAIR said:
It should also be noted that you could play hell with the fuel pressure regulator because of where the outlet is. Best bet is to keep part of the stock steel hardline that goes into it and clamp the hose to it. A budget set up could be using the stock feed lines as the return as the stock return lines are horrible in the rear of the vehicle where they step from 5/16" to 1/4" over the axle. I personally as well as some others on here have had the stock return line plug in this location.
Click to expand...


Unless cut the bottom threaded part off the regulator and use a weld fitting.

attachment.php
 
disco stu said:
Exactly.





Unless cut the bottom threaded part off the regulator and use a weld fitting.

attachment.php
Click to expand...

If you are using an aluminum regulator such as an accufab that could get tricky as aluminum likes to warp when you weld it so plan on remachining the face that the diaphram sits on.
 
I used a 1/4" npt to -6 90*fitting. The bottom of the regulator is not 1/4"NPT but it threaded in a couple of threads then had it welded all the way around. No problems with warpage. The inlet is a steel -8 straight fitting that I hacksawed off and welded.
With the -6 return line, I use an intank ATR double pumper running both pumps full time. No Problems
 

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Those fuel lines are running over the dp, they must get hot, couldn;t you run them on the driver side some how?
 
norbs said:
Those fuel lines are running over the dp, they must get hot, couldn;t you run them on the driver side some how?
Click to expand...


No problem with heat. They're about 4-5 inches away and the pipe is thermal barrier coated.
 
I think people tend to overeact to so many things on here someitmes. I too was worried about the heat from the downpipe until I saw how the factory fuel line came off the rail inlet and went right by the dp.
Also, the adapters I used are not any kind of restriction at all, Just a safe and practical method of connecting the two components.
I know I have driven my car on some pretty good trips and was concerned about heat also but I do have the shield on the turbo still and I have never felt any kind of heat to be concerned about. No I wouldn't grab the downpipe or anything stupid like that I am just saying it's not 1000 deg. like everyone makes it sound.
Sorry for the rant.
I hope you found your solution for your fuel lines.
Oh and I second the post about not using the hardline unless you are excellent at bending lines. I looked into it and it was far easier to use the braided.
 
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