50psi hose for return lines?
- Thread starter Cubey
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DrCharles
Full Access Member
The pressure in the return line is next to nothing... it's an open 5/16" line all the way downhill to the tanks. I think the cover is there more as abrasion/heat protection than actual reinforcement.
Huh. Well, I guess I'll go get some cheap fuel hose then. I kept the old braided from my F250 and its original caps. I used separate viton orings i had bought separately before i realized the ends of the hoses were cracking. So I have brand new orings from the bwd kit i bought 2 years ago. I just need hose since the E350 probably needs it too.
DrCharles
Full Access Member
Just make sure it's diesel-rated (which won't be quite as cheap). Gates' Green Stripe or Barricade should work, can be had at O'Reilly etc. That stuff is rated at 50 psi anyway 
I'm using a piece of it to connect the left and right banks in front of the intake opening since adding the turbo.
I'm using a piece of it to connect the left and right banks in front of the intake opening since adding the turbo.
That looks like the same stuff I used fyi. No problems that I've seen yet.
DrCharles
Full Access Member
That'll work too, and Gates says it's OK with diesel
http://gatesunitta.com/en/gates-submersible-fuel-line-hose-4219-series
http://gatesunitta.com/en/gates-submersible-fuel-line-hose-4219-series
That'll work too, and Gates says it's OK with diesel
http://gatesunitta.com/en/gates-submersible-fuel-line-hose-4219-series
Great. Now parked in a driveway where I can work on it as long as I need to. Hopefully it won't be too horrible.
I've done the job before so I know how it goes, its just different when you're working inside a small cave instead of under a large, open hood.
ttman4
Last Nite's Dream..
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I have used that clear braided 1/4"-5/16' hose from Lowes & Home Depot on two of my rigs for return lines for several yrs with no air intrusion or leaks. I also use it from fuel filter to nearly the IP so I can see any air. I just cut the steel line supplying the IP 3-4" from IP, clamped clear braided hose on. I like it because I can see any air if ever any is there anywhere.
lonnoid
Registered User
I have a question, does anyone know how much fuel returns to the tank in the return lines? i.e. ounces/gallons per hour?
IDIBRONCO
IDIBRONCO
The ONLY place in our fuel systems that sees even close to 50PSI (stock) is between the injector pump and the injectors. Hence the steel lines.
that is going to be a steady trickle, how much exactly is up in the air. depending on driving load and the age of the injectors. the more they are worn, the more they will pass though some fuel.
The_Josh_Bear
Full Access Member
Yep, the volume of fuel returned to the tank via the return lines is the same amount that your lift pump is rated for, minus: filter restriction, lift, fitting restrictions and whatever small amount the engine is using too.
Basically all the fuel not used by the injectors is returned via the return line coming out if the IP. Whatever comes out of the injectors themselves is very very little.
Of course a mechanical pump will have a varying fuel supply that rises with engine RPM, and with an epump it won't change much except it will lower slightly at WOT vs cruise since you're burning more fuel.
At idle, the pump is calibrated for 1 cc per stroke at 750 rpms. At that rpm That’s 100cc per second the pump will output in the injection lines, not a 100% of that goes to the cylinders, let’s say 30% of that goes out the return, so 70cc of fuel per second is being used by the engine at idle. So take a flow rating of the lift pump at idle, and subtract what the engine is using and you have your exact return flow.
Or as said in the other thread just unhook the main return line and take measurements in a graduated cylinder
Or as said in the other thread just unhook the main return line and take measurements in a graduated cylinder
