[thedrbrian]

They don't use magnetos because they're scared of modern tech, its because magnetos self excite and don't need an external power source to start or keep running. And that modern 2 litre engine isn't going to put out max power like the aero engine will.

[jandrese]

The aero engine is also air cooled (so no water pump or radiator) and generally simpler all around. But at the end of the day it has a hilariously large displacement for the horsepower delivered. It's not like the thing is using fancy variable timing or partial charge ignition or cylinder deactivation to save fuel either, it has to fill those cavernous cylinders with a combustible mix on every fourth stroke.