greg,
to be short, suppose you are using a 2 stroke and you substitute the ether of a simple mix1/3, 1/3, 1/3. Within the crankase the kerosene is yet in liquid phase, so the oil is diluted 50-50 by the kerosene. This means that the natural viscosity of the lube is halved. Now pass to the mixture where ether has been substituded by some fuel similar to kerosene (an bio IS similar to kerosene by this point of view). Now the diluition is 33-66, that means FURTHER HALVING of the viscosity. Do you really think your engine happy to run on such a stuff?.
It may seem absurd, but it is true, REDUCING ETHER REDUCES WORKING VISCOSITY OF THE FUEL!!!! So this is the FIRST problem, the LUBRICATION. Instead of asking " does whale oil burn in place of ether? " one has to ask " does whale oil in place of ether reduce engine lubrification?"
.... next we will reflect of what mean for COMBUSTION the droplets of an etherless mix and their coalescence.....
ugo