Something that I thought about a while ago, but perhaps deserves a mention......

When playing about with lubricants other than castor oil I reckon it is vital to ensure that the engine doesn't run with a lean mix.

A chief benefit of using castor oil is that it will protect the engine against a lean mix and the very high temperatures generated much better than any other oil, including synthetics. Nothing has quite the same protective qualities that castor oil provides.

It will be far safer to run the engine slightly rich, but NEVER lean when using alternative lubricants. This means we need to remember that the engine "unloads" a bit in flight and the mix will go a bit leaner as it will when the tank level drops low.

If playing with "modified" vegetable oils it would not be a good idea to subject them to operating conditions that only castor oil could survive ! []

Reg