If this is true why has every attempt to use Auto engines in aircraft ended either in abject failure or major disappointment in the sustainable power reliably produced?
It's typically not problems with the engine itself, but with changes or systems that have to be designed to install it in an aircraft:
- A custom cooling system, to provide enough cooling without excess drag
- A system to turn the propeller at an appropriate speed, without transmitting vibrations to the engine that it is not designed to handle
- Perhaps, you put a different ignition system on to give you redundancy
- Perhaps, the oil system (sump) is not designed to work in the range of attitudes encountered in an aircraft.
- You probably have to fit all this in a space designed for some other type of engine
None of these systems are likely to have the detailed engineering work done that was done on the original engine installation, and they are the typical areas where problems are encountered. It's no different to dropping a Lycoming in a car and discovering you have cooling problems, and have to strip the engine after a sudden stoppage when your foot slipped off the clutch.
I'm not arguing for auto engines in aircraft. Creating a reliable installation is a major undertaking. It's much easier to choose an engine that was designed for the task, where it is well known what is required for a reliable installation. But I don't agree that aircraft engines are superior technology to auto engines.
Some of the things encountered in aircraft engines that would not be acceptable in a car engine:
- manual mixture control. My car engine automatically runs lean cruise (lean of peak) when power settings allow.
- worries about shock cooling
- having to strip an engine or check the crank after any sudden stoppage.
- a manual primer pump, or the incantations required to start a hot fuel injected engine. Chokes on cars disappeared decades ago, if you told people a fuel injected engine could be harder to start than a carby engine they would think you are mad.
- new engines making metal with the frequency that seems to happen with aircraft engines
- worries about corrosion in engines that sit unused for a while
- changing a cylinder etc. way before the projected engine life.