Upgrading fuel lines help

[Jetpilot]

I am upgrading my fuel lines from the stock lines. My question references the weber adapters that go into the OEM fuel filter and VP44... . Has anybody tried drilling them out to see if we could get better fuel flow? The hole in these fittings that the fuel flows through looks even smaller than the OEM fuel line between the fuel filter and VP44. Can this be done and still get a good seal with the aeroquip fittings? All of the other holes are normal -6AN but these are ALOT smaller .



Any thoughts are appreciated.



Doug

 

[HVAC]

Aluminum Fittings

Jet, I'd advise against drilling aluminum fittings. I have noticed a difference in one manufacturers weber adapter I. D. compared to another.

 

[Jetpilot]

Nowel,



These are the areoquip fittings. Do you recall which brand has the largest orfices?



Thanks,



Doug

 

[Diesel Freak]

I did not bother drilling my Aeroquip fittings. They flow much more than the OEM Banjos and drilling them is more trouble than it is worth.



They should have a little over . 25" ID... this is not a problem since the filter is the main restriction after installing a custom fuel system.

 

[Jetpilot]

Diesel Freak,



People have said the OEM filter will only flow about 40-45 GPH, but I have been unable to confirm this. I am not sold that the . 25" diameter hole is large enough... . All the fuel lines are around 3/8" so that is a pretty small hole for the fuel + there are 3 fittings of this type to restrict flow. just my $. 02 worth.



Doug

 

[Todd T]

I drlilled my aeroquip fittings out to 3/16"



like you i thought they were pretty small to start. i have only had them on the truck for a few thousand miles but no problems yet.

 

[Jetpilot]

WOW,



Drilled out to 3/16"!!! That means the orfice is alot smaller than . 25"!..... Boy I am going to have to go take a look and see what I can do to help them out No pun intended!



Doug

 

[Jetpilot]

Went out and measured the I. D. of the weber fittings, they were 5/32"! So drilled them out to 1/4" they now match the -6AN I. D. much better. I will report back once there are on as to leaks or any other abnormallity. Hopefully I didn't just ruin 3 weber fittings.....



Doug

 

[Bigsaint]

Good info Doug, keep us posted on the results .



Scott W.

 

[Floor It]

you guys know that thay do make a #8 to 12mmx1. 5 thread fitting dont you?

John

 

[HVAC]

It took me two pieces to adapt from fe 12mm to m -8 flare. I only encounter this combo at the pump since everthing else is larger.

 

[Floor It]

The fitting I'm talking about is one piece, its from Earl's products.

12mmx1. 5 straight to a #8 fitting.

John

 

[Turboman]

Ted Jannetty has them. Also look at Wag Aero , they have all the AN stuff you could hope for. Oo.

 

[Jetpilot]

Ok guys here is what I did... . drilled out the weber adapters to 1/4" installed -6AN lines from the OEM fuel pump and VP44. Prior to this I had installed new 3/8" lines from the tank to the OEM fuel filter and used Rays banjo bolts. A Mallory 4140M was installed back next to the fuel tank outlet with a Mallory 200 GPH pre-filter. This setup was yeilding 17 PSI at idle, but I could drag the fuel pressure to zero with the box on 5X5! Now I have the idle set at 16. 5-17PSI at idle and NEVER see below 12 PSI . In fact the only time I see the fuel pressure drop is when the peddle is on the floor and on level 4 or 5.



Needless to say I am very happy!!! With the OEM lift pump I could drop fuel pressure to zero with just the Super Mental injectors. So to be able to keep 12 PSI when the fence posts are blurred is wonderful. I also installed my adapter for my fuel pressure gauge close to the VP44, my concern was to see fuel pressure at the pump not upstream. I plumbed it so the sender is mounted close to the firewall, this kept the added weight off the VP44 and adapters used in the install. The gauge seems very solid and accurate, I know some members had erroneous readings from this location but I think plumbing it the way I did worked out well.