Swirl

[PGAHOWELLS@domain.elided]

Nothing wrong with A series engines. Surviving 60ish years. Powering Mini for
years and years. Winning Monte Carlo rallies. Done just a bit better than the
poor old Stag engine, even though the Stag engine obviously has a special
place in my affections.
The article which includes references to swirl and tumble is called Old
Bottle,New Wine and can be found at. 
http://popularmechanics.com/popmech/auto2/9609AUTKM.html
I hope you all enjoy it.
Peter Howells