Veg Oil

[Timelord]

I did a load of research into this WVO thing a few years back. At the time I was happily running a 300D merc & Disco landie on Biodiesel & straight veg oil a lot of the time - that was until they put the prices way up on veg oil and also when the biodiesel outlets mostly closed down as the suppliers concentrated on big haulage companies only.
I started looking into the WVO option. there were loads of sites on different ways to do it. After quite a lot of searching, I came across a site that was run by a very experienced vehicle racing engineer and he explained some very important facts that were omitted from all the other sites. This is that WVO is not the same as Veg oil with just food waste bits in it. He explained the complex chemistry as to a lay person. I can not remember it all, but basically - When the veg oil is used for cooking, typically in a Fast Food outlet, then it undergoes complex chain molecule changes. Also this is enhanced by the repeated reheating of the oil in the fryer units of the restaurant. Often the oil is used all week with just the particulate matter scooped out - until the end of the week, when it is changed completely.
These molecular changes produce some very bad chemicals that are now contained within the oil. Cleaning at home & removing water etc with the conventional kits does not remove these chemicals. This means that when you then burn it in your engine as a fuel, it not only produces various toxic gases exiting from the exhaust, but also these chemicals can have serious effects on the longevity of the engine and its associated components, like seals etc.
Also, the engineer had stripped down quite a few WVO engines and found that bore glazing was common place. This is the result of incomplete combustion of a very small amount of WVO, especially when the engine was cool. (It pays to start up on normal diesel). this glazing was absolutely miniscule per operation of the engine, but it built up in layers over time, until it impeded the piston ring movement within the bore and causes piston ring break up or chamber damage due to "gumming up". The glaze proved to be almost impossible to remove without re-machining. This was due to the multilayers all being effectively baked on as a hard glaze.
Different engines were effected more or less by this but it was characteristic of the chamber burning process of the fuel.
I do hear many mutterings about veg oil cars generally having engines that do not last as long as they should. I do not know if this is true and I sold mine before it ever had any problems.
I believe this glazing problem applies to WVO & straight veg oil.
I do not now have the web address of the article, but it may be possible to locate by searching the web.

I am listing this info for general knowledge on the subject and am not able to verify its content. also, It may or may not be useful to anyone considering WVO or veg oil.

(Some engines & fuel pumps can be seriously damaged by running on veg oil or WVO - pls do your research - info for novices only)
Regards, TL