Hello All, I don't normally post on very many sites but I was asked to describe how I make rings, and the difference between my rings compared to other rings. After reading some of the other posts I just want to say if you are happy with your engines that is great, happy flying. If you want more performance with smoother lower idle, more peak RPM, better compression and lower operating temperatures then maybe you need a different ring. Manufactures generally make rings oversized, cut pin notches & slit rings with various sizes of slitting saws so when rings are installed the ring will close gap. Often pre load tension in rings is too much to try & force ring to seat in cylinder. Their machineing methods sometimes will cause rings to be out of round or uneven. By the time the ring seats ring gap widens and during operation that much tension just heats engine more than low tension rings like mine. My rings are round to begin with so I don't need to force them to seat and the low tension prolongs ring life with lower temperatures during operation. I will tell somewhat of my methods of making Piston Rings but please understand there is a lot more involved than what I will discuss here. I make my rings from solid fine grained cast iron bar stock. My finish cut on outside diameter of ring tube is .002. I machine the O.D. to exact cylinder bore dimension. This will insure a round ring without grinding OD. After finishing I.D. I part off rings from machined tube, ring thickness + .002. I use a feeler gage in Piston Ring Land to determine what correct top to bottom ring thickness should be. I hand lap ring to correct thickness, cut in anti rotation pin notch in rings if pistons are equipted with pins. Then I use a custom made tool to snap ring. I then stack rings on jig, secure with tie wire so rings stay flat on the jig during heating process. I place an outer sleeve over the rings and mount jig on my home made turn table. I then spin jig slowly while heating outer sleeve to a little over 1,850 degrees F, red hot. Radient heat goes through outer sleeve to rings stacked on jig. After slight cooling remove rings from jig to cool. I then hand file ring to get .001 to .002 gap to a bore gage that I make for every ring size. Cast iron is the one of the least expanding metal during the heating process soo ring gaps need to be kept tight as possible as all other metals from steel, aluminum, plated metals, chromed metals all expand more than cast iron. There is a lot of confusion as to ring gaps, which includes large gaps for lubrication of cylinder walls, etc. I have found large gaps allowing hot gas to escape down into crankcase and just heats engines more. All I know is a tight ring gap doesn't affect lubrication but does increase power. Loose gap means lower compression, less power, higher idle, lower peak RPM. I have made thousands of cast iron rings for Gas, diesel, glow fuel, 2 cycle, 4 cycle, marine, motor cycle, snow mobile, engines all with tight gaps. I'll let my customers tell what my tight ring gaped round rings do for their engines. There are 2 employees in my business, My Wife & Me. I get my insperation & guidance from my Lord and always try to deal fairly with all in my business. All I wish for is to make the best ring & do the best I can in everything that I do. Thanks Frank Bowman