@corsac @theUnrequited They are the normal O-320 and O-360 engines. Many (if not most) of the low-compression #Lycoming and #Continental engine installations have an #STC for #autogas.
They were originally designed for #AVGAS 80/87 so require 87 MON (Motor #Octane Number, used for aviation engines) at full rich mixture. SuperPlus, a common "high octane" fuel in Europe) has a RON (Research Octane Number) of 98, and a MON of 88, so can be used safely.
#generalaviation #mogas