So I have had some free time and decided to tinker with the extra banjo's I got after putting the FASS on my truck. I have the one with the schrader valve and two extras from the dealer refit after they warranted the stock engine mounted lp with an in tank unit and put the bypass block in.

I am running the 1/2" fuel line to the filter housing then the stock fuel line to the vp.

I drilled the 2 lower, thread side, holes out to 13/64" and eased the exit port like the stock ones and polished them a bit with my dremel. I use a plumber's tool I had to take the burrs off the entry side a bit but can't get in there with a fine stone to polish them up, but they are pretty clean. The exit holes are eased out and look smooth under a magnifying glass.

I plan on replacing the fuel filter housing outlet banjo and the vp entry inlet banjo's with my modifyed ones.

Not expecting huge gains, but just trying to give a little more volume/flow for kicks.

Did I miss anything? I scoped them and cleaned out any debris from my machining attempt.

Ready to install...

 

Sounds like a good project. I would be the most concerned about leaving a hidden burr inside that can come loose and float downstream, but it sounds like you've got that covered.

Do you have a gauge so you can monitor pressure at full load to see how much difference it made? Am curious to hear your findings.

 

Good point, I am going to micropolish the insides just to be safe!

My concern is the one with the test port going into the vp.

I do have a gauge, but am thinking I'll be increasing volume more than anything so am expecting a slight pressure drop....

 

I'm sure the gain will be noticeable on an decent gauge.. for what its worth I gained 2 to 3 psi at WOT with a 15k trailer when I installed a 3/8 inch big line kit between the filter and VP, eliminating the banjo bolts..

Keep us posted!

 

I did the samething to all banjo bolts. I didn't really monitor before/after psi but with this, it increased the volume....not by much but hey it's better than nothing. Eliminating them would be the best option for the most volume flow.

 

SIXSLUG there used to be what was called "high flow" banjo fittings you could purchase. I guess they were basically the same thing you're trying to achieve. The problem though is that when you drill out the OEM ones you make them very weak and you're not really gaining anything worth the time and effort. For around $50 you can purchase a "big line" kit probably from most vendors which consists of two JIC fittings and the line which runs between the filter housing and the VP. There used to be a tapped 90* barbed fitting which is intended for the fitting at the housing but I'm not sure if you can even find them anymore. If you cant and you're pulling fuel pressure readings from that location then you'd need to install an inline tapped barb fitting. If $50 is to costly then you can probably just order the JIC fittings and the length of hose online. Just make sure to get the right thread size.

Now in saying all that, yes the banjo fittings where HUGE flow restrictions and deemed the worst part of the fuel lines but there was on restriction that was worse. All the OEM metal fuel lines are 5/16" ID but between the fuel filter and the VP, one of the metal fuel lines was actually 1/8" ID. Strangely though not all trucks had this tiny ID fuel line so I cant say whether your truck does or does not.

Running larger fuel lines and high flow fittings is a good upgrade because you want to eliminate all unnecessary restrictions in the supply fuel line and make the VP the most restrictive part of the fuel system.

 

Thanks Katoom, good advice.

I only drilled out the lower two holes so I didn't interfere with the seal on the two near the bolt head, but now I am going to look into the line between the filter and vp.

I wasn't really expecting any performance improvements I could feel, just trying to elongate the life of my original vp!

I am gonna look into the bigger line kit. I have 1/2" fuel lone from the tank to the filter now.

Thanks and any new opinions welcomed.

Kurt

 

Sounds like you're onto something good here.

 

Your right Kurt in that doing so the only gain would be potential VP reliability.....and no performance increase unless your fueling was so aggressive that you needed additional volume for feeding a very hungry engine.

Ditching the supply banjo's and increasing the line diameter is a good idea because it allows for better fuel pressure retention and ample flow from the fuel pump during throughout the throttle curve. The smaller lines and restrictive fittings do a poor job of keeping up with demand and therefor ask more from the fuel pump as the pressure drops.

 

I am running the FASS at the stock setting, 16 psi, so I think it can keep up with my internally unmodified engine and at 136K my original vp is always at the back of my mind when traveling.

On my runs to Kalispell and back I am always thinking about potential worst case scenarios for breakdown spots and have already had one when my ecm went out a few years back.

So, I am gonna address this now and hopefully ease a little more life out of it (knocking on head)!!

 

For 50 bucks I'm not going to risk rolling the head off a banjo I hot rodded....(Good advice Katoom!)

Ordered the vulcan kit yesterday!

 

Hope it works out.

 

Thanks!

 

Got the kit from Vulcan yesterday!

Nice stuff.

 

If you got the pushlock fittings, a little wd40 will help getting the hose on the fitting much easier!