Page 73 of Charles Fayette Taylor's book
"The Internal Combustion Engine in Theory & Practice"
has this set of graphs showing that in addition to Quench Clearance,
Quench Area is also important.

The 'Performance Number' on the left hand side is another name for Octane Rating of Gasoline, in this case the US Army-Navy substitute that they claimed to be superior to either ROM or MON, but where PN=100 is still what the chemical octane acts like when used as fuel.