Fuel line routing and banjo bolt help requested for two tank system - Page 2 - PeachParts Mercedes-Benz Forum

Jimmy Joe · #16 05-09-2004, 11:23 PM

I sure am glad that I am not the only one freaking out about how to filter veggy oil.
And that damn Mercedes banjo bolt plumbing...
Don't mean to imply that you guys are necessarily freaking out, but I know I am.
How about filtering the veg prior to running it through the stock filter? Running a solonoid switching the returns? (diesel to diesel tank, veg looped)
Wouldn't have to change much Mercedes plumbing.
Plug the banjo bolt, maybe.
How much mixing of fuels would occur with proper timing of solonoid switching?

I just want to get this pig rollin on the veg, biodiesel is too damn expensive...

djugurba · #17 05-09-2004, 11:46 PM

have you looked at www.greasel.com and read their suggestions on plumbing? I have some other components, but I'll probably go with that method I think. I don't want to mix fuels in different tanks, and I don't share a filter and dont want to backflush, and I need to look at my stock fuel filter housing to see if I've got that hollow banjo nut.
My set-up will be as follows: veg tank heated w/coolant heat exchanger, hose on hose travels to veg filter, through additional heater, through pollack, through lift pump, into IP. diesel will go from tank to stock filter through pollack, into lift pump, into IP. return will make a loop into the post pollack feed. If I get air, I'll put a 3 way brass valve in there or maybe just purge through the #6 injector end. but, my sdl has an automatic priming system; no hand pump like the 85-older has. I have to crank the engine to get the fuel through and it purges the air back to the tank. So, I was thinking the 3 way brass valve could have a return to the stock tank (biodiesel in my case) and I could use that if I had air. Yeah, I'll probably do that...
cheers!
Kevin

Jimmy Joe · #18 05-10-2004, 12:32 AM

Thank you all,
You are making it materialize in my brain.
Dugurba, you sure make it easier to visualize the plumbing with purge.
Yes, I have read everything Greasel has to offer, and still the specifics of the banjo bolt don't make sense.
They give the specifics of the solid bolt, but not what happens to the IP return line. If the bolt is solid, doesn't the IP return line hit a dead end?
How is that ok?
Just leave the three lines and block them?
Anyhow, I am not so worried about temp of veg oil, for the last thing before my oil hits the IP will be the Veg Therm from Neoteric.
I just really don't want to mix fuels.

coachgeo · #19 05-10-2004, 11:48 AM

Quote:

Originally posted by Jimmy Joe
Thank you all,
..., and still the specifics of the banjo bolt don't make sense.
They give the specifics of the solid bolt, but not what happens to the IP return line. If the bolt is solid, doesn't the IP return line hit a dead end?
How is that ok?...

Upon looking back I can see how a solid would work IFFF my memory of how the design works. Just take yours off and see. Replace the brass washers. Very easy to remove and wont harm anything.

Here is a pic to show how the flow from the ports not be blocked by a solid bolt.

pdxwaker · #20 05-10-2004, 12:11 PM

take a look at this thread
http://biodiesel.infopop.cc/eve/ubb.x?a=tpc&s=447609751&f=159605551&m=740601947
for info on a looped vegi/return to tank diesel w/ filter backflushing (diagram included!).

Jimmy Joe · #21 05-10-2004, 04:54 PM

Coachgeo,
You totally rock!
If you are correct about the return still functioning with a solid bolt, you will have saved the veggy community a whole lot of grief! Thanks a bunch for your thoughts here.

coachgeo · #22 05-11-2004, 12:36 AM

Quote:

Originally posted by Jimmy Joe
Coachgeo,
You totally rock!
If you are correct about the return still functioning with a solid bolt, you will have saved the veggy community a whole lot of grief! Thanks a bunch for your thoughts here.

Just unbolt yours and take a look. As you look at the Banjo part you'll see that the walls of the banjo allow fuel to flow around the bolt. I think there will be holes in the sides of the bolt near the head. This is where the air and fuel from in the filter below comes up thru the bolt and mixes with the two inputs from the Injectors and the IP.

Bolt is metric. Take it with you to a bolt/nut place to get one w/matched threads.

Jimmy Joe · #23 05-11-2004, 01:46 AM

Quote:

Originally posted by coachgeo

Bolt is metric. Take it with you to a bolt/nut place to get one w/matched threads.

The bolt is hard to find at hardware stores, and easy to find at cheapo auto stores like Kragen. Thanks to Greasel for the specs:
12-1.50 X 20 MM C/S 8.8