Merugo,
I have followed your olive oil experiments with some interest. I have made modified oilive oil to use as a lubricant but only by means of "cooking" it in a pan on the stove.... however the stuff seems to work !

I take a commercial model diesel engine fuel with 30% ether content and 24% castor oil content and dilute it down as follows....

To make 1 litre of fuel with a 10% ether content ...

2.5% ignition improver 25mls
12.5% Synthetic engine oil 125mls
16% modified olive oil 160mls
10% ether 100mls
8% castor oil 80mls
kerosene 357mls

This was the last fuel mix I tested and is so far the best. Winter has intervened and more testing will be done in the better weather with the intent to reduce the ether content and also reduce some of the oil content in favour of more kerosene.

The mix shown gives easy starting... with a starter motor, and runs exceptinally well. The idle is very slow and very steady and acceleration is fast and smooth even after idling for a couple of minutes at a time.

I have tried other mixes... some with no ether at all and some with just synthetic oil as the lube and kerosene as the fuel component.

From my testing I found that...

Fuels with no ether at all will run OK in my model diesel engines.
However.... they require high ether primes to get the engine hot enough to start and the crankcase temperature increases considerably.

High ether content i.e. 30% reduces engine temperature but more noticeably the crankcase runs considerably cooler with a lot of ether present.

I also tried using just castor oil and reduced ether content, and here I hit problems. If the ether content is reduced then there will come a stage where the castor starts precipitating out of the mix. I found that 25% castor oil needed 15% ether content. If the ether was reduced then the mix would go cloudy when left for a few minutes and a deposit would appear at the bottom... this would probably get worse at lower temperatures.

To recap...

My experimenting got as far as the mix shown above. That mix gives incredibly good running and would be acceptable both on performance and especially price for my use. It gives reasonable engine temperature and the crankcase is at (what I think is ) a temperature which is acceptable.

The mix has been thoroughly tested and I included engine runs of 20 minutes at a time with up to 4 minutes at a time at idle speed. The engines would accelerate without any "hiccups" after several minutes idling, throttle response was very good throughout the range.

I will be happy to use this mix but will also experiment a bit more just to see what else I can achieve. The castor oil is in the mix only because I haven't a source of ether so I dilute normal high ether content fuel in order to get ether into my "homebrew" mixes.

Including modified olive oil in the lubricant has definitely given easier starting and smoother running.

Engines used were PAW both 1.49 and 2.49 models. Fuel mix was initially tested in non-RC Paw engines and when they didn't destroy the engines then it was further tested in RC versions so that the throttle response could be evaluated.

Somone else is having great success with a somewhat simpler fuel mix....
18% used engine oil..... drained from his crankcase at oil change time !!!
2% ignition improver
80% ordinary diesel fuel obtained from the garage pump !!!

Reg