Good day all,

I did some more reading (till my eyes glazed over and my brain siezed ). You convinced me that the process of cooking veggie oil as some have been using is not the same as making biodiesel.

I just rediscovered a forum that Andy already had about biodiesel stuff.

http://biodiesel.infopop.cc

I have posted some questions about our cooking veggie oil process with relation to biodiesel in the hope that someone in the know will provide a clearer understanding.

here : http://biodiesel.infopop.cc/eve/foru...1/m/5151043661

and here: http://biodiesel.infopop.cc/eve/foru...3/m/3361084661

for anyone cooking up a batch of veggie oil, common consensus from much reading of the above web site seems to indicate that Canola oil is the better choice with soya oil not quite as good; however the difference between better and not quite so good is very small and with all things gleaned from the internet, to be taken with a grain of salt.

This is an interesting site if you have any interest biodiesel / green fuels. Lots of rhetoric but lots of interesting tidbits as well.

In any respect, I took some time to continue my biodiesel testing yesteday before the rain started. In these tests I added 10% kerosene and 10% ether to the straight B20 biodiesel (20% biodiesel 80% mineral diesel). Assuming that the unburnt oil's that I have been seeing in previous tests is the biodiesel and has been acting as my lubricant, the addition of the kerosene and ether reduced my oil content from 20% to about 15 to 17%, still acceptable I belive - remember my test engine is a old nearly worn out PAW 2.49CC.

This mix ran well, better than the B20 biodiesel + 5 or 10% ether. Less messy, less oil coming out of the exhuast but still a white/light blue tinged exhaust. Notice that I did not use any Cetane Boost.

Next test was the same mix with the additon of 2.5% Cetane Boost (Amsoil brand). It did not run as well. Compression and needle valve setting where more sensitive and it did not run out the full tank of fuel before stopping on it's own.

I have never had a clear indication in any of my testing of what effect more or less Cetane Boost had until now. Clearly 2.5% Cetane Boost had a deterimental effect over the mix without. I have been using 2.5% as it seemed to be a good figure, common convention or wisdom was always to add ignition improver at about that percentage. From now on I think I will less, 1.5 to 2% in fact. I realize that ambient temperature and humidity has an impact and under certain conditions more may be beneficial but I would rather compromise and a more all around figure.

I repeated my test just to verify what I saw the first time; mix without cetaine boost and then with, same results.

And then the rain came ;(

All this messing about with the B20 Biodiesel has been fun and interesting I think it may be a bit of red herring. While it does work I/we have not proven that it has sufficient long term lubricating properties although my test engine shows no short term wear but as Andy commented on the condition of his connecting rod it may just not be good enough.

I am not sure we will ever find a substitute for ether but we have shown that you can run these small engines without it and that some is still handy for starting. During one of searches of the net I found an article on the use of ether in commercial diesel fuel use; proposed for much the same reason we have been using it - it's low self ignition temperature.

Incidentally did you know that many years ago ether was drunk like alcohol for the same inebriating effects? Those that drank ether were called (I think) ethermaniacs. Apparently the effects where shorter lived than when one drinks alcohol. And, in order to get as much ether down your throat and into your stomach, they would have a drink of very cold water first before the shot of ether. Ether was commonly available at that time and drinking it was common until they re-classified ether as a poison which ended it's easy availablity. This over 100 years ago.

for an interesting time line of Ether see: http://www.erowid.org/chemicals/ethe...r_timeline.php

If nothing else, this thread has shown that we do not need to use ether in the amounts previously specified and there are alternatives to castor oil, amyl nitrate and IPN as well.

In reference to my previous post about the self ignition temperature of mineral spirits (I can often buy it at a lower cost than kerosene) Turpintine has a self ignition temperature of 220 to 255 C. Turpentine is usually a non-petroleum product and may have some interesting properties in a fuel. I wonder what burned diesel fuel spiked with turpentine would smell like ? better? worse? Another experiment for another non-flying day.

cheers, Graham in Embrun near Ottawa Canada.