This past weekend I finished the conversion on my 240D and so far all is well. I've driven about 300 miles without a hiccup, and am so far very satisfied with the results. The system is set up as follows:

The stock tank has a heated fuel pickup (hotrod) installed, and is now my veg. oil tank. For startup and purge fuel I have installed a 3 gallon marine tank in the trunk. I used the stock diesel lines for the start/purge fuel lines, and added a HOH under the car for the veg. oil lines. Start/purge fuel returns to the 3 gallon tank, and the injector overflow always returns to the veg. tank.

From the HOH, veg. oil flows to a facet electric lift pump, then to the heated filter, then to the FPHE, then to the valve and finally to the IP. The return fuel is looped back to prior to the lift pump unless I decide to return back to the start/purge tank to purge air. The stock lift pump is used only when running on the start/purge fuels and is deadheaded on veg.

I'm using greasecar valves, one for switching fuel into the IP, and one for switching the return fuel. For system info. I am using an electric temp. gauge whose sender is on the outflow of the FPHE, and a vacuum/boost gauge T'd to the ip inlet. So far my fuel temps. range from about 140 F to 180F depending on speed and coolant flow. My fuel pressure is about 12-14PSI on start/purge fuel, and 4-6 PSI on Veg. oil.

I'm considering switching the fuel pumps and using the stock pump for veg. and the electric pump for start/purge fuel. Other than that I think I'm done tinkering as it is time to get back to the maintenance list.

I've really enjoyed owning and driving this car so far, and now I think I have the ultimate commuter car. To view photos of the conversion, go here:

http://www.kodakgallery.com/mattdavis/benz_wvo_conversion

This sounds like the perfect two-tank Benz conversion. I'm certain that you'll have many, many trouble-free miles on VO. From what I've read, the Benz should be happy with your temp ranges.

If you ever need faster switch-to-VO times, a bit of electric heat would do the trick.

I'd contemplated an almost identical setup as you've described before I decided to single-tank a blend (and may still add a 3-gallon tank this fall). The only addition would have been injector line heaters that, ideally, would have allowed me to switch to VO within a few minutes of cold starting.

At this point, I switch to veg. about a 1/2 mile after cold starting at 50F ambient temps. In the summer I will probably switch as soon as the car is started. I'm pretty impressed with the FPHE as my temps. come up pretty quick.

My hope is to get this car restored to minimal maintenance condition and to where is it consistently driveable in winter VT conditions. For winter use I will have to add more heat, so I will probably add another heat exchanger before the lift pump and perhaps injector line heaters. For summer use, I think I'm good though.

With my plumbing setup my switchover time (post switching the valve) is very quick and it is amazing how quickly the engine changes sound. The injection noises go away within 30 seconds of switching, and the injector nail that I often have on diesel goes away completely. My purge times are also very quick.

Thanks for posting all those photos.

I'm trying to wrap up my 82 300sd conversion (w/25 gal. auxillary tank in trunk this weekend...

Where did you source your power for the 2 valves and the pump? Do you use inline fuses? I have next to zero electrical know-how, so I won't be offended if you could explain to me how to apply power to these three things like I'm a three year old

I'm also using 2 greasecar solenoids, and a small fuel pump for the veggie oil.

Enjoy the conversion - and I'll actually be out in your fine state (stowe) next thursday for a wedding...

I got power for all my components from the ashtray. As you can see in the photos, my veg. system control panel is where the ashtray used to be. For the cigarette lighter, there is a plug with power and ground right in that space, so I just used male spade connectors and tapped right into that plug. There is only power to this plug when the key is on which is ideal.

I drilled a hole in the firewall (the only hole I drilled for the whole conversion) to get the wires and tube for the pressure gauge to the engine bay. The power from the pump comes from the same wire as the veg./diesel switching valve so the pump comes on when the valve is powered. I did use inline fuses between the switches and the components.

You should get an ammeter if you don't have one for testing circuits for power and good grounds. You can also get power form the fuse panel in the engine bay in front of the driver. I believe #6 is a good spot to get power with a female spade connector bent slightly. I have seen several conversions where people got power from here and ran the wire into the engine bay.

Hope this helps...and enjoy your time in Stowe.