Long story short, when I decided to convert my car, I wanted to save some money and reduce the impact a VO kit would have on my trunk and engine space. Since most of the pre-made kits had large rectangular box tanks, this ate up all the room in the trunk. And since the Jetta's trunk space is limited, I needed to move elsewhere. Also, I wanted my engine space to just have the selector valves and hoses occupying it. The rest (Heat Exhangers, Filter, Filter Head, Pump) would need to be underneath the car and in the inner fender area.

These two tasks (the Fuel Tank and the Valves) needed to be custom.

The valves were easy: I constructed a "frame" of sorts that that was made out of 1/8"x1"x36" aluminum bar bent in the shape of a "U" with a slight jog at the side. The jog accommodated the oil dip-stick. Image here. I drew a tracing of this when I installed it (that shows the bends and hole locations), but I don't have a digital copy of it. I'll try to upload it soon.

The Tank design was not as easy. I needed to find space to make an aluminum tank (steel reacts with WVO--polymerization) that would hold at least 10 gallons. Underneath the trunk in the 1998 VW Jetta is a large open space. I took some measurements and calculated that if I didn't want to make some minor changes to the bumper cover flanges, it would be about a 6-gallon volume under the trunk. However, if I just pulled out my reciprocating saw, I could remove the bumper cover flange and have space for a ten-gallon tank, with a sloped bottom.

I drew up a quick schematic and started looking for fabrication shops. I wanted someplace local so I could avoid shipping costs. I drew up this and started emailing shops. Royal Manufacturing of Santa Ana was the lowest bidder and I re-submitted a more detailed drawing with what we mutually called the "Ear Flange." This was the actually shop drawing and feel free to download this, if you want to have this custom fabbed. The "Ear Flange" was designed by me to make a thru-bolt connection for my 19" HotFox Fuel Pickup. Arctic Fox sells A-1721 or A-2060 horizontal adapters, but they are a couple hundred dollars a piece, plus you have to wait to have them shipped. This "Ear Flange" works great and I don't have to worry about stripped threads if I need to do a hotfox removal.

The tank was finished quite quickly and looked great. I gathered the other items necessary for the kit and laid them out. The last portion of the custom install was how to organize the components into hidden areas. This image shows how the Filter Head, Pump and First Heat Exchanger were organized between the Diesel and VO Tanks. This space was unintended, but appeared after I had installed the new tank (happy accident).

The last heat exchanger was installed in a small space in front of the passenger side tire.

There is a lot more about this in detail on my site and the Installation Pages start here. The total installation took only two weekends to do, but gathering the parts took probably a month prior. Since then, I've been adding more to the site, regarding the Modifications Page.

Lastly, feel free to use my designs or drawings--they are free to use as is. I accept no responsibility for them (all the old legal mumbo jumbo ), but I've been using them for over a year now it's great. I try to give away as much as possible and if you use them, please post your images to this forum (or others). In the spirit of giving, a colleague of mine and I known for our VO marathons and if you happen to live on our path, we'd like to see your VO setups--And if you can spare a cube (or many ), we'd greatly appreciate it.

Oh I almost forgot, here's the entire 1998 VW Jetta Custom WVO Schematic.