Smoking engine

[Ian Williams]

I am interested to know what the effect on this type of ring would be if the gap was too small or too large - the picture suggests, to my mind, that the ring has opened up beyond circular and the section opposite the gap is not making contact with the bore?

If the rings have opened up beyond the circular it would suggest that they are for a smaller bore size, are the compression rings showing the same markings ?

Colin this was exactly why I asked what gap, I believe that at least one of the engines I have encountered was fitted with the wrong size rings and that one had a large gap. Others were less conclusive so it is possible there was a bad batch of rings in circulation or they were over stretched when fitted.