Back at it again with another project. Before I start asking questions, I'll start with the plans to put the questions in context.
So, I want to build an E-fuel setup for my 96 PSD
. Being the person that I am, I want to do it myself, do it right and use my creative abilities to save a couple bucks. I am going to be using two Napa 4770 filter bases, CAT
filters, the Super Duty pump, and a Fuel Labs pressure regulator (pretty standard I know). Now, I know that fuel aeration kills performance and reliability, so what do I do? I look at how it's been done before. FASS and Air Dog both have kits that separate air from fuel. Here's how they do it. Aerated fuel comes out of the fuel pump, this in turn flows into the low micron filter of your choosing. Air in the fuel prefers not to flow through a wetted low micron filter membrane, much like how it is harder to breath through a wet cloth than a dry one. The easiest way to get the air out of the fuel being sent to the block is to allow a portion of fuel being sent into the filter to be bypassed. Naturally the aerated fuel gets pushed to the bypass because it is easier for it to flow there, and the non-aerated fuel gets pressed through the filter. The biggest difference between the high dollar kit and this will be that they have a nicer pump (could go buy a better pump), and that their bypass vane is a little more optimized for this type of thing. I think the Napa 4770 base will do just fine for my needs. Normally the aerated bypass fuel is sent to the tank return line. Which is what I plan on doing but my concern is that the stock 5/16" return line wont be able to support the FPR return fuel as well as the bypass fuel.
So, here are the questions. Will the stock return be able to support the extra fuel being dumped into the line? Those of you who are using the Air Dog or the FASS kit, what did you do as far as plumbing for the return line? I am planning to set up a test bench to see if this will all work the way I theorize it will. I suspect I will have to play with bypass line sizes, but that's not a big deal. My next question is what will happen if I end up trying to send too much fuel down the return line? My speculation is a couple of things, increased wear on the pump, higher pressure in the return line, and perhaps more wear on the FPR. Is that a problem? I am not really sure, this will be the first time I have built a fuel system. I do however have plenty of folks around me who have built fuel systems, though mostly for gassers and nothing with a fuel air separator. How do I calculate the the volume of fuel returned from the FPR? Is it as easy as volume from pump minus consumption and bypass? How do I calculate my consumption?
I realize, my goal of keeping the switching valve and dual fuel tanks makes this more difficult. I considered getting a second switching valve, wiring and plumbing them in parallel, and modifying the fuel sender. That seems like a lot of work though. Would love to see the insides of the switching valve to see if it can be modified, but I suspect that would be really common if it was doable. I also looked around for another switching valve, and I found some but I need more information on how the one in our truck is actuated/powered. Any thoughts would be much appreciated. Thanks for reading!
96 F-250 4x4 ECLB XLT ZF-5 4.10
3" down pipe to 4" exhaust, bellowed up pipes, TS 6, pre-turbo pyro, stock injectors, hutch and harpoon
Turbo: 66/88 6+6 billet wheel, KC S300 style turbine, 360° thrust bearing 1.0 A/R exhaust housing, 3.5" ported anti-surge 1.15 A/R compressor housing, EBPV delete tube and pedestal