VE return line upgrade ?

[ChrisWilliams]

I'm in process of replacing the fuel system on my 91. 5 and need a little info on the return line. I was planning on hooking up a larger return line directly to the VE with a 16 psi check valve, tee into the injector return and run back to the tank. When I pulled the return banjo off the VE, I noticed the tiny tiny orifice in the banjo. Now, I'm worried about returning too much fuel to the tank and starving the VE. I have searched and found a lot of discussion about the return line, mainly dealing with increasing HP. I am mainly concerned with increased cooling and lubrication, especially with this new ULSD. So, what kind of pressures will a stock VE see on the pump side of the return banjo? If I plumb the new return line directly into the VE with a check valve, the most pressure I will have is 16 psi. Has anyone done this and how did it work out?

 

[Greenleaf]

The internal pressure on these guys is like 100-120 psi for an average joe rig. It is controlled by the speed of the internal (vane) pump and the setting on the internal regulator... ... ... . AND the return orfice. (and the KSB too!) These return fittings are not adj as you see. On other model pumps, they are.



If you want, you can remove the return restriction but you'll need to make some provision. And thusly, you will need to increase the internal pump pressures accordingly. You gotta have internal pressures becasue this pressure feeds the hi-pressure head AND adjusts the internal advance.



Clear as mud right? No body ever said that re-engineering a fuel system is easy. BTW, there has been much R&D performed and it will be kinda tough to get all the 411 on this. It won't be all free info. You'll have to set-up and do some R&D yourself.



BTW, you can gauge the internal psi and you WILL want to increase this beyond OEM settings. The front pump seal is modified because it is a lip seal. Not an O ring.

 

[ChrisWilliams]

Got it, I suspected something like that. I'll put the stock return banjo back on and connect my new return line to the tee at the back of the motor. I should have her singing by nightfall or a little after. Thanks for the info.