Originally Posted by
jonnyjetprop
There is on going research into electricon ignition systems that would allow big bore engines to run on a special aviation fuel. It's unleaded gas that I think is around 93-94 octane. The issue is that the ignition system would detect knocking and adjust the timing.
On a second note, it's problematic to run a low compression engine on auto gas. You can't use fuels that have ethanol mixed in it.
On the contrary. Ethanol is used as a detonation buffer. It takes much more ethanol to make the same power as a petrol based fuel, but it also generates significantly less heat, which is one reason why the lead is added to av-gas. I for one, am against an ethanol based fuel, because it costs energy to make it (more energy goes into making than it yields).
The reason why we don't add ethanol to av-gas is because of the what the engine cases are made of. There is a measurable amount of magnesium in the case (block) of opposed engines to save weight. Ethanol corrodes magnesium, and the unburnt fuel that makes it way past the rings would corrode the case over time.
We can do it without completely overhauling the system. If we increase the octane (which will generate less heat) and eliminate the lead, in theory, problem solved.