The long-term report on the Electroair electronic ignition retrofit on a Lycoming O-360 engine (October 2023 Aviation Consumer) proved there is a significant advantage over traditional magnetos, but there are also significant differences between the Electroair and the SureFly electronic ignition. I’ve been flying with one SureFly electronic mag installed on the Continental IO-470-N engine (I installed it myself with the supervision of my A&P) on a Beech Debonair. Here’s my field report.
Advancing the timing
We know from experience with air-cooled auto engines (old Volkswagens as one example) that advancing the ignition timing causes the engine to run hotter. This is likely due to more complete burning of the fuel/air mixture and the longer duration of the hot gases in the cylinder. SureFly’s installation requires a digital engine monitor to monitor temperatures if the spark advance is to be enabled, while Electroair’s does not. Apparently, since Electroair does not advance the spark quite as much as the SureFly, Electroair did not think digital engine instrumentation or 100-octane fuel was necessary with their installation. SureFly included those requirements likely due to the slightly higher maximum spark advance. Moreover, I don’t conclude that SureFly’s engine monitor requirements make the SureFly inferior—buyers investing in ignition upgrades likely have them anyway.