How to make own piston ring and which material are used:

http://modelenginenews.org/techniques/piston_rings.html , http://www.alanstepney.info/page27.html , http://www.homepages.mcb.net/howe/NewsMakingRings.htm , http://www.btinternet.com/~sylvestris/rings/rings.htm . [sm=thumbup.gif]

I used the material from brake disc and camscaft, they are made of cast iron. Works wery well in my model engines.