Where did you get those AI #s Andy. I got totally different #s like 210 C. for kerosene, 280 C. for gasoline and 550 C. for naptha - oposite ends of the scale.

Here is where I got my info:

http://www.engineeringtoolbox.com/fu...res-d_171.html

Personally I think that my free used RPM Dello 400 15-40 may be as good or better than single vis. 50 wt aviation oil. We need the oil to be thinner when it is cold so it can go through the carb. and thicker when it gets exposed to higher heat wich is what multi vis does.

Vegatable oil would be great if it works well as a lubricant but I don't trust it. As far as I know it has never been used ( except castor ) as a lubricating oil in any engine in modern times ( last 75 years or so ) One of my concerns is it may not have good viscosity stability at different temps. Say the rod bearing beggins to get hot due to friction and high loading like a little over compression - you sure wouldn't want the oil to thin out too much then....

I flew for another hour yesterday on my 5% either Black Brew mix. This works well. I still haven't tryed kerosene yet....