Thanks to the chap who posted the Alpine/Renault channel in the Alpine topic.
https://www.youtube.com/watch?v=RvAR28gD_YA
This image which I imagine is from a much earlier (I am sure someone will recognise it) Renault engine shows a detail which helps explain the the problem of the unburnt in the top ring land area, a simple chamfer being the solution.
I wonder if this carried on?
I assume ! that the later engines have moved the single ring much further up to near the chamfer.
I always assumed (what a dangerous practice) that the piston movement allowed that volume to be burnt but of course that reduces the produced pressure , so this is a great solution.
