A while ago I found a Lister CS 6/1 with a radiator. The plan is to restore her to original condition and then take her on engine shows. I have removed the piston and found that the top compression ring is wider than the next one. In fact 2x normal rings were fitted in the groove. I believe some Listers came out with a wider groove and that this could possibly a 8/1. Please note that this is my first try. All help and support will be most wellcome. Kind Regards, Deon.