Hi Andy,
I thought I would post the method of making modified olive oil as the original posts around modifying vegetable oil are a good way back in the pile now... saves rooting back to find them.

The olive oil is by far the best way to go, I wouldn't bother with cheap cooking oils anymore having seen the difference, and also heard the difference when the engine is running.

I haven't a clue what the temperature is when "cooking" the oil, it was bubbling merrily so I guess it was boiling. If the oil gets too active just turn down the heat a bit. Once the foam has stopped increasing put the oil on a very low simmer until the foam goes. With cheap cooking oil there was a lot of foam and the heat had to be turned down otherwise it would have overflowed from the pan. The olive oil doesn't exhibit this behaviour, there is not a lot of foam produced at all.I find there is still a bit of foam left on the surface after simmering... don't sweat it as it doesn't seem to make any difference. If there is anything critical about the process I haven't found it

Foam will appear when the oil heats up, there won't be a lot with olive oil and you can soon put it onto simmer. If you spend more than 20 minutes on the process then you are being waaaay too fussy.

Use 15 cc (or even 20cc of glycerine as it appears the olive oil will benefit from a bigger amount than cheap cooking oil.

It might be worth using about 30% olive oil in the fuel mix until we find out more about it.

I made up a litre of fuel today. I made it to the 10% ether recipe. This fuel is intended for flying purposes in my non-sacrificial engines so I used castor oil as the lubricant. The fuel mix looks a bit cloudy... it's in a brown glass bottle so can't tell properly. I am wondering if the castor is not dispersing properly with only 10% ether content ? It may be that I will need to use part castor and part olive oil if I am making a "super safe" mix. I want to use the super safe mix while I continue experimenting with olive oil lubricant and non-ether mixes in my "sacrificial" engine.

I bought some easily read measuring jugs, including very small ,size with a view to mixing accurately. Some things, like the ignition improver where more of an inspired guess rather than an accurately measured amount.

I only put in 5% of the 2-ethylhexyl nitrate ignition improver.... good job I did as my original intention was to use 10%.

I put some of the mix in the tank of a PAW 1.49 and choked to get fuel to the carb. A spin or two of the starter was needed to establish the required starting compression setting. Once I found the setting the engine started and ran straight up to speed without any effort. I backed off the compression and let it run for a few seconds. I adjusted the needle and compression for optimum running and...................... the compression was equal to or even slightly lower than when using 30% ether fuel !!!! Needle was just about 1 turn out from closed.

The ignition improver seems to be compensating for the lower ether content. The engine runs with much less compression than I expected.... glad I didn't use 10 % as I originally intended.

This could bode well for a 5% ether mix as a bit more ignition improver or a slight compression increase might give equally good running.... work in progress

I need to try a non-ether mix with a measured 5% of this ignition improver and see if I get the same effect - or - if it is only apparent when ether is present. I noticed an improvement the other day whe running 10% ether with olive oil mix, but that was just adding a few drops extra. Measuring it more accurately so the correct amount is present gave very good results.

I am hoping to go do some flying tomorrow, I will be using a couple of PAW 1.49's one with RC carb and one without.... should be interesting [X(]

Reg