Bulk virgin VO should be filtered too. The human digestive tract is SIGNIFICANTLY less picky than a BOSCH diesel injection pump.

I don't mind filtering the oil at all. The part that turns me off is the heating of it which I thought until now wasn't necessary if mixed with dino and run at warm ambient temps. (60F+)

Thanks
David

I would certainly filter store oil myself. But I would not worry about de-watering it, nor settling it. That is the difference.

If you filter it at near 60°F and it doesn't get significantly colder than that you should be ok. You may do better to mix the veg and diesel thoroughly before you dump it in the tank. The real risk would be to let the oil sit out in the sun and get hot, say 90°F, filter it and then the temp dropped to the 50s you may be changing some extra filters.

Put some test batches in the fridge and look for it to cloud.

I don't filter store bought oil, I have only run a little, not enough to have strong feelings for it. I would filter bulk oil from a processor.

I was just reminded of this good read on oil fron Neoteric:
http://www.biofuels.ca/page16.html

David,
I collect oil which is mostly liquid at 60'F, It contains ~30% solidified oil, which is suspended in the oil. As I filter this oil, without ANY heat, the high melting point solid oils are retained in the filter.
I agree that the oil and diesel should be mixed before adding to the fuel system.
Although I recommend adding a fuel heater, many people have had success without adding heat to the fuel.

There was one person who (reported on the biodiesel forum) had a bad experience using an unheated blend, (IIRC, not in an MB vehicle) where it is suggested that petroleum waxes in the diesel were released from the diesel some time after the blend was made, causing issues with his IP.
If you are concerned that this may occur, you should consider using kerosine or gasoline as the blending agent, rather than diesel.

Have you seen much feedback on heating blends? It seems that heating a blend with RUG could lead to vapor lock. Anything above 125°F, 51°C would worry me a little. Diesel blend should heat to 140°F safely.

Twitchkitty,
Not much on the subject, but it would depend on the blend ratio and the location of the heater (before or after lift pump) and it's efficiency.

As I do not blend with diesel, petrol or kero (only biodiesel) I do not have any personal experiences, although, come to thinlk of it, I did add about10% petrol to some WVO when I was having lift pump problems, to help diagnose the problem. I did not have any vapour lock issues at that time, but I agree that it is possible.

If your system gets that hot there is inline fuel filters with a bleed port that can be used to prevent vapor lock. These were designed for gasser engines prone to vapor lock. These 3 port inline filters are available at any cheapo Autopart store.

What about lubricating qualities of a heated blend? This is of course going to be ultimitely variable with percentage, types of fuel/oil used, but through testing a rough approximation standard could be developed.
If I were going to do blends, I would be concerned about this.

Ok, so do you guys wire the heaters to run anytime the key is in the "on" position or do you guys have a switch?

I wouldn't mix the diesel and oil outside the car. I wanted to maybe have 2/3 tank of diesel then top off with WVO or SVO (you get the idea).

If I went the heater route, would I want to heat the tank or fuel lines?

Thanks
David

This isn't exactly what you asked, as I am running straight veg on a second tank, but I do have an electric inline heater (in addition to coolant heating), and I have it wired to a toggle switch which is lighted as well. That gives ultimate flexibility for various fuel use. If I were to run blends, I either would not coolant heat the tank or lines at all, or I would have ball valves in the coolant lines so I could eliminate heating entirely when I wish to run diesel.

Fractional crystallization is the concept behind what I am saying about clean oil plugging filters as the oil cools. This is the process used to separate air products, that was my exposure to it. Different components in the air freeze at different temperatures and pressures. A similar concept is fractional distillation which is one of the processes used to refine petro products.

Wire your heater with a fuse, switch, and relay.

That three port filter, I assume the vapor vent would go back to the fuel return?

As the vegetable oil has a MUCH better lubrication than diesel, the lubricity of the heated blend (even at 5% WVO), would be significantly better than cold diesel.

This is a good question and I don't know the answer. I suspect that the lubrication qualities are good up to the temperature where the oil smokes. IIRC, that is when the fatty acid chains molecularly rearrange themselves to form trans and/or CIS fats. Or maybe they carbonize and form free fatty acids, something like that.

I have a real good link somewhere about veg oil chemistry if anyone is interested I can probably find it. Just don't read the part about the synthetic fats that are in the food chain, it may make it hard to sleep at night.

Besides, my buddy will probably give me an injection pump if I really need one.