Originally Posted by
NutLoose
One thing that struck me of interest was a while ago I attended a Shell seminar on their products.... they i am sure said that because of the PC'ness against leaded fuels they had been trying various cocktails to try to produce a lead free Avgas but they were not getting anywhere close to the power output,
Having much experience with dime a dozen auto engines that run on 87AKI fuel at 10:1 compression ratios with zero knock via modern combustion chamber design and ignition control, I'm absolutely floored by how ridiculously bad a motor as agrarian as an aircraft motor has to be to not run well on this fuel. Lots of aircraft engines can't even run at rated power on 100LL without using excess fuel for cooling/detonation margin. The dual plugs aren't just for redundancy, the mag check demonstrates that these motors actually need two plugs to burn most of the mixture.
IMO the problem is not the availability of suitable alternative fuels, its the availability of the capital needed to certify modern sensible alternative powerplants. It looks like the industry is going to skip right over the modern gasoline powerplant it should have been using for the last twenty (or forty) years and go straight to oil burners.