Need little help, Starting my Vege Conversion, have fuel filter questions (617 turbo) - PeachParts Mercedes-Benz Forum

coachgeo · #1 08-03-2003, 11:36 PM

ok... all the conceptual planning has come to head now and I sorta figured out my plan on this step of things for my WVO conversion.

I could use Ya'll help please. With out getting into all the theories of why it seems to not be damaging to the IP.. I want to run what I call a "Modified Fuel Return Loop" on my 5cyl Turbo engine.

"Modified Fuel Return Loop"

Quote:

Take the fuel return hose and loop it back to the filter (or just before it) instead of it going back to the tank. This is what is considered a normal "Fuel Return Loop" in WVO set ups. My modified version does the same but bleeds off a "little" fuel and any air into the normal fuel return line.

ok... that being explained now. Anyone got an idea on how the stock fuel filter on the 617's can be modified to allow a little fuel/air to bleed off the top into the regular fuel return line to the tank? I dont have a manuel nor have I taken the fuel system apart before to know the flow paths of the fillter in stock form. I understand that Ford filters this is not to much a problem. Other filters you cant do it at all. I have a plan (I hope) if that is the case with the MB filter system as well.

Thank you in advance for your comments.

coachgeo · #2 08-04-2003, 06:54 PM

Originally posted by dang10010 on the Biofuels B.board:

Quote:

The fuel filter has a T on the filter where it either returns to the tank or back to the pump. I have had a clogged filter (not the stock filter) and it resulted in no oil (fuel) being returned to the tank. Hope this helps.

From this I gather that in stock format the fuel return cycles back thru the filter then gets T'd off to either engine or tank. Basically it has a built into it what I was calling the "Modified Fuel Return Loop"

Can anyone verify this?

If this information is correct I could see putting a valve in the return line after it leaves the filter that I could use to restrict the flow of the returning fuel thus forcing more to go to the engine than goes to the tank.

More detail on the other option I mentioned:

3-port gasser fuel filter:

Maybe put this on the return before the MB fuel fliter line and loop the main fuel out back to a T into going into the fuel filter and "smaller line" going out to the tank. Plug the return line from filter to tank at the filter. Though this is inexpensive it is sorta dumb to add this in if the MB fuel filter sorta does air bleed already.

Originally posted by JonO on the Biofuels B.board:

Quote:

...common disposable automotive fuel filters that have a 3rd port with built-in restriction. This is to keep fuel flowing through the lines therby avoiding vaporlock (obviously for carbureted cars). Cost about $4 at any parts store. Just clamp one into the loop and it'll vent a trickle of fuel anywhere you like.
Cheers,
JohnO
Fram G3798, G3583, Purolator F21117, Wix 33040

COMMENTS PLEASE!!

some question areas are:

How much fuel is returned to the tank in general in stock form on the MB 617 engine. 90% 30% ??? 100%

what are all the lines into and out of the fuel filter. Their are quit a bit. Sorta looks like a sprouting potatoe its got so many hoses branching off it

I'm sure I could figure most out but I dont have one sitting next to me in this little messy office of mine

and it would nice to have something to verify my thinking is correct when I stat putting it all together anyway.

coachgeo · #3 08-04-2003, 08:17 PM

thanks for the title Change Eng...!!

Greasy · #4 08-04-2003, 08:57 PM

I have a 83 300Td that I have converted to wvo.
What I did was use a 6 port sol valve, tee the wvo return back to wvo supply, but the diesel from main tank I kept the supply and return to tank.
I did this so if I get air from the wvo, (I feel the engine start to hesitate) I can switch to Diesel and any air will be purged to the tank. Works good. I have run about 5000 miles so far on wvo.
So I dont think you will need a modified return system

coachgeo · #5 08-04-2003, 09:07 PM

Quote:

Originally posted by Greasy
I have a 83 300Td that I have converted to wvo.
What I did was use a 6 port sol valve,...

Yep that is one way of doing it. One of the most common ways infact, but I dont like it. The method Im looking at doing removes the need to do like you say and switch to diesel to remove air. Also I am not using a 6 port valve. I have 4 fuel tanks and buying enough 6 port valves etc. is crazy. Also if Im in the middle of South America or OZ (ok so Im sorta dreaming) and a electrical problem kills the 6port valves Im in a world of hurt. The previous owner of my Mog; who traversed the Saraha and Siberian deserts, and Iceland in this truck, hince so many tanks, already had 4 manuel valves installed for swithcing from tank to tank with the return only going to one of the tanks. I'm using this same format with my system.

If you want to get totaly confused here is a link to what Im doing.

http://biodiesel.infopop.cc/6/ubb.x?a=tpc&s=447609751&f=159605551&m=372600382