Just a quick note about NACA and SAE papers:
They are usually based on engines with combustion chambers inferior to those we use, so their AFRs might have to be richer just to catch up because of poor atomisation (usually they have no squish, swirl or tumble, hell not even fuel injection often)
Then we have the fuels themselves, they can vary a lot. Even recent SAE papers are based on test engines that would mimic model "T" quite well :lol: and fuels used could be worse than those found in the backstreets of Delhi in plastic containers. That is how you get the range of 80 to 100RON, while we'd be more interested in 95 to 115RON :wink:
The range is still 20RON but I'd bet that the flamefront would move differently.
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