Ok,

My brother-in-law has an 82 300D that he acquired a couple months back. Runs well, but he wants to start using WVO in it. Fine by me. Anyway, tonight over a few beers we started discussing it, and here is where I simply have to bounce this off of the forum.

He wants to do a two tank conversion, but right now he simply cannot afford one of the pricey ready made kits, so we put our heads together for a simple affordable system he could build himself and here is what we came up with.

He will buy a small tank for WVO and put it in the trunk. To handle the fuel switching, we figured we could get two 3-port valves (one for the fuel supply line and one for the return) and manually control them with toggle switches. The one for the fuel supply would be tee'd in just before the primary fuel filter/primer pump. Return would be tee'd in where the cigar hose meets the metal return line.

A separate fuel line (with an additional filter) would be run from the WVO tank to the supply line tee and a separate fuel return line would go back to the WVO tank. In essence this would give him what he needs...two complete but separate fuel systems. To handle WVO heating the plan was to use a Veg-therm or other fuel line heater connected to a toggle switch just before the additional filter and 3-way valve on the WVO supply line.

To operate he would start on regular dino diesel and bring the engine up to operating temperature. While the engine is warming up, he would flip the switch to pre-heat the WVO line. Once the engine was up to operating temperature, he would flip the switch to change the fuel supply from dino diesel to WVO, and at the same time flip the other switch to change the return fuel flow so it would go to the WVO tank. Conversely, he would switch the fuel flow and return back to dino diesel about 2 miles or so before switching the car off.

There you have it. Please let me know what you think. I'm sure the experts will pick it apart, especially the fuel return set up and the possibility for Dino/WVO cross contamination. I just ask that if you see a problem, please also provide a (inexpensive if possible) solution at the same time.

I think as far as wanting to build his own two tank system as cost effectively as possible, this one should work

Glenn

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2012 Mercedes ML350 Bluetec 91K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 231K (mine)
1998 Volvo S70 T5 Turbo 196K (kids)
1994 Ford F150 4WD 249K (firewood hauler)
1983 Mercedes 300D 376K (diesel commuter)