Bending fuel filler pipe - PeachParts Mercedes-Benz Forum

pdxwaker · #1 04-25-2004, 12:05 PM

I pulled a fuel tank from a W123 that I plan to use for WVO in my '85 300DT. It should mount pretty cleanly in the trunk but I haven't figured out how to modify the filler pipe yet. I'm looking for ideas on the best way to bend this pipe so I have easy access when the trunk is open (for filling the tank with veg oil). The pipe is fairly long so the length shouldn't need to be adjusted... it just has to be bent and re-routed. Any ideas on the best way to bend this pipe (without expensive specialized tools)?

-John

TonyFromWestOz · #2 04-25-2004, 12:16 PM

Hacksaw and rubber hose, secure with hose clamps.
I have the intention of doing the same with my '84 300D also. The tank from the 250 is perfectly clean and would be a good candidate for a WVO tank. I want to have a coolant line (copper) brazed to the bottom of the tank, to allow the use of oils with high tallow content. By brazing to the bottom of the tank, there is no possibility of coolant/fuel contamination.

leathermang · #3 04-25-2004, 10:02 PM

I don't know exactly what diameter pipe you are talking about.. but the usual way to bend pipe with less chance of crimping it is to fill it with sand before bending it ...

pdxwaker · #4 04-25-2004, 10:52 PM

Tony from Oz... I'm interested in your 'brazing' suggestion. Do you think this would provide good heat transfer to the fuel in the tank? I was planning on using copper lines inside the tank so there would be some (though not much) chance of coolant/fuel contamination. Have you seen this brazing method used before?

-John

coachgeo · #5 04-25-2004, 11:10 PM

another possible tank for Veg. oil that is plastic, somewhat portable etc. is one of these

Nice wide openings since they are made to attache RV sewage line. They have available for them simple gauges etc. Cost are reasonable too.

Find them here

I think JC whitney has them too.

TonyFromWestOz · #6 04-26-2004, 08:56 AM

Quote:

Originally posted by leathermang
I don't know exactly what diameter pipe you are talking about.. but the usual way to bend pipe with less chance of crimping it is to fill it with sand before bending it ...

This pipe is the fuel tank filler pipe. A steel pipe, and not really suited to the sand method, due to the fact that it is short and attached to the fuel tank.

.

TonyFromWestOz · #7 04-26-2004, 09:21 AM

Quote:

Originally posted by pdxwaker
Tony from Oz... I'm interested in your 'brazing' suggestion. Do you think this would provide good heat transfer to the fuel in the tank? I was planning on using copper lines inside the tank so there would be some (though not much) chance of coolant/fuel contamination. Have you seen this brazing method used before?

-John

No, I haven't, but I attach a photo of the tank from my 250. The metal is flat around the strainer location and the steel tank would provide reasonable heat transfer to the fuel in the tank. The problems with doing this to a tank, in the normal tank location, relate to the height that adding a copper pipe would add to the tank mounting position, and the vacuum resivoir above the tank would then not fit there.
There may also be problems with the copper rubbing on the trunk floor.
With an additional tank, this could be catered for in the installation, with appropriate insulation and tank supports.
But then, you need to bend(?) the filler neck.
I was thinking of using the tank flap from the exterior of the body of the donor vehicle, fitted to the other side of the body, as an external WVO tank filler.

TonyFromWestOz · #8 04-26-2004, 09:38 AM

W123 Fuel tank filler neck

leathermang · #9 04-27-2004, 07:10 AM

Sometimes things can not be done with them still in the car....
No one has said how much more bend is needed and in what distance it has to be accomplished....
I don't work with heat on empty gas tanks.... they are filled with water after several total cleanings.
Tubes for musical instruments ( horns ) used to be filled with tar before being bent.
With the straight section showing .... I would use a pipe cutter, take the part of the tube off needing bending and fashion proper jigs to do the job... then put it back in place and weld it back on.
Or you might find a muffler shop which will use their hydraulic machine to bend it for you.....

coachgeo · #10 04-27-2004, 09:33 AM

Leathermang may just have hit on the easiest thing to do. Cut off the pipe with enough left on the tank to clamp too. Take it to a muffler shop and have them bend a piece out of stainless steel the way you need. Have them expand this to fit over the tank end for clamping. Seal it with JB Weld. Cut the fuel cap end piece from what you removed from the tank and have the stainless part expanded so you can clamp this over the end of the for your fuel cap. They can weld this part on while it is not connected to the tank. Mock it up and mark it good first before welding.