Ok....so I've done lots of research, thermodynamic calculations, etc lately in deciding what to do. I want to make my 4000 mile cross country journey across the country before school starts up again a reality, but the only way it's going to happen is on WVO.
Here's what I came up with...in terms of making my own heat exchanger, using exhaust gases to heat the oil was far and away the best method in terms of getting up to temp in a reasonable amount of time and getting HOT. However, flexible copper is up over $1.00 per foot right now. Hydronic baseboard heaters run about $10 per foot right now. Tranny coolers with enough surface area are $50. A-coils from a central air system contain too many plastic parts. Basically, I've decided against building my own heat exchanger. Instead I'm going to buy a flat plate heat exchanger off eBay. The one I found is comparable to the $170 unit we sell at work (it's actually rated slightly higher). I like how compact they are and they are well proven for WVO conversions. The one I plan to buy is listed below.
As for a tank....again I've been wrestling, but I think I'm just going to buy a new poly tank and avoid all the headaches. I can get either a 35 gallon or a 65 gallons from work for $75 or $135 respectively. They are similar to this one. http://cgi.ebay.com/35-Gallon-Horizo...QQcmdZViewItem
They are heat and chemical resistant. The only problem is that they only have one NPT fitting on them for the supply. I will have to drill and install a return line fitting. The cool thing is that the supply fitting is an inch or two above the bottom of the tank allowing for some settling room. I'm not sure which tank I will go with. The 65 gallon tank has the obvious advantage of not requiring filling up as often, but the 35 gallon will take up far less space and since it will be in the living room behind my seat, that's something to look at. Either way it will be enclosed and have a bench or something on top of it. The size of the tank really doesn't matter in terms of heating has the heating will be done downstream in the heat exchanger.
For valves I'm going to go with the 1/4 turn brass valves. I can get them cheap at work...much cheaper than the $75 Pollack electric valve. I just don't trust anything electronic plus they will allow me to prevent any WVO from returning to the diesel tank, as little as it might have been.
I haven't decided on hose yet. The clear vinyl "beer bong" hose is cheapest and is pressure rated for much more than this system will ever see, but the hot oil will be at the upper end of it's thermal ratings at the given pressure so I'm not sure about that. Rubber fuel hose is much more stout and runs $.70 per foot for 3/8ths, the biggest we carry where I work. Copper is probably the most stout option and allows heating with a torch if all else fails, but is prohibitively expensive right now. We just underwent another price change on it this week.
I have yet to find an appropriate pump for priming, etc. I might just try and see if I can get it to work without it. If I can't get it to run well without it I'll sink some money into a pump. No big deal...I guess. We used to have a neat little pump that chucked into a drill where I work, but we have since changed suppliers and can't get it anymore. Oh well I guess.
For filtering I think I will use a hand pump through a 20 micron fuel filter/water seperater and a 10 micron finishing filter. We sell both of these for cheap and the Goldenrod brand is common enough to not have a problem. They are cheaper than the water filter method and are designed for this purpose locally. I think I may try and figure out a gravity feed system so that when we park and go out and about it can do the work for me as I know we cannot haul anywhere near enough WVO with us on this trip. Even with a 55 gallons drum where the shower will eventually be and the 35 gallon tank full we will only be running 720 miles or so on WVO. Obviously fill ups anywhere possible along the way will be necessary. Thankfully we're never in a rush to get anywhere.
The only problem that REALLY remains is getting it all installed and tested in the next 3 weeks. I also need to come up with as much GOOD veggie oil as possible which may be a little more difficult. Most of the oil around here is partially hydrogenated. It's "liquid" at room temp, but not all THAT "liquid." Perhaps I'll be trying the naptha trick anyway. Either eay I'm going to have a big bottle of cetane boost, injector cleaner, and some spare fuel filters with me. Any thoughts before I proceed as planned?