zu,

I know where you're coming from. Growing up near metro boston my family cut, stacked and split 6 cords of wood a year to heat our home for 20 years. After I went to college Id go back home to help my dad out with it.

I throw the monetary/time facts out right away for folks looking into WVO because it is not necessarily the best bang for the buck. You have to enjoy it. It is not easy to do long term, neatly (as in your garage and car don't smell like grease pits) and correctly, IMHO. Some people would say otherwise.

My in-vehicle rig in my 85 300D is essentially a stock Frybrid 3-valve system. I added to that a ISSPRO temperature gauge right before the IP inlet so I could monitor the temperature of the fuel. The frybrid site has a good explanation of the basic plumbing of the system and the reasoning behind it.

I also added a shut off valve for the system. This means if I do not intend to use the 2nd tank, I cut coolant off to it with a valve (in this case a simple ball valve). This means you don't heat the WVO on short trips - important to do to keep the fuel from polymerizing in the system (BAD).

My fuel tank is 21 gallons, and sits right behind the stock tank - I like that arrangement better than replacing the spare tire with the 15 gallon tank that is popular with grease car kits.

Why 3 valves? The third valve is a purge valve - it allows you to purge the fuel system in 15 seconds or so at 1000 RPM. This means you don't need to 'burn off' all the fuel in your IP and it also makes sure that no WVO goes to your diesel tank.

The system is automatic - theres a controller that monitors the coolant temp and turns the system on automatically. You push a button to purge the VO and the controller automatically purges for a set amount of time. The automation is nice and allows me to give the vehicle to anyone and send them on there way. All they have to do is push one button.

So in practice it takes me about 4 miles to heat the system up to temperature on a fall or spring day. If I am not going more than 10 miles I leave the system off.

Fuel temperature in operation is about 175F-180F. In the winter, I block the radiator with a piece of plastic (ironically, a for sale sign) to maintain this temperature. I have a stock 80 degree thermostat. For purge, I purge about 22 seconds. It is a little more than I have to do, but I like to ensure that Im totally free of VO in the fuel system.

So no-no's for VO use:
- not generally a good idea to idle for a long time. This encourages carbon build up on the cylinder walls using VO. (It should be noted idling for a long time on diesel isn't good either)
- not a good idea to heat the oil up and down repeatedly if its not being used. as I mentioned before...
- don't use biodiesel in the main tank! this sounds like heresy, but petrodiesel is much more stable and since the main tank doesn't get used much it's better this way. also, you can verify switchover of the fuel purely via exhaust smell between the petrodiesel and the WVO.
- dont depend on your in vehicle filter. i filter my VO outside the car to 2 microns, even though the vehicle fuel filter is 10 microns. I don't want to be on the side of the road changing filters.

That's all for now on the vehicle side of it.

And by the way, this seems like a Frybrid love letter, but it is hardly. I would not encourage anyone to buy from them if they want to be running WVO this decade. If you have the skills you can fab your own kit easily. I should have.

The preceding is all from my experience running VO for three years and 40k miles. Opinions will vary.

HTH,
dd

PM me anytime, Im happy to share what I know.

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car