A lot about how an engine breaks in depends on the metallurgy involved, and for a ringed engine, the hardness of the ring, how round it is, and how round the cylinder liner is are the important things also. I learned that you break any engine in by running it at normal operating temperature under a normal load for extended periods of time. With our engines, we can monitor the process by checking the exhaust for metal in the oil that comes out, and by examining the ring to see how it looks during the process. If it's a ring than has been heat treated , this will take longer. The load is regulated by using a smaller diameter and a little less pitch that you would when flying. Excess load can cause over heating that can have bad results. Generally , we do usually burp the engines a little bit into a higher, cleaner RPM to clear things out and see how it returns to the needle setting. We just usually pinch the fuel line for a fraction of a second to do that. I really don't know if increasing RPM just into a low two stroke setting would speed things up or not. I don't think I have ever seen this question come up before. I guess the best way to tell is to try it, and check the ring frequently during the run, and check the exhaust also. I think you would need to do this to several engines in order to get a feel for how it's working. My experience with ringed model engines is mainly with Super Tiger G-.51 and .60 engines, and those generally don't take very long at all to seat. And again, how round things are can affect all of this one way or the other. That is one thing Tom Lay would check on each engine he did, and if necessary, hone the cylinder a bit to make sure it was truly round.
  Type at you later,
   Dan McEntee

It would help to know some details about the engine. For most sport/stunt ringed production engines I would run a couple ounces through it at a rich setting with a normal prop then put it into service. If you run it too hard/hot before surfaces are smooth, aluminum from the piston can get stuck to the bottom of the ring but, a couple ounces of fuel will smooth it out enough. Just flush it out good after run so goopy oil doesn't stick the ring.   

MM  

Is there a significant difference in running temperature between alcohol- and white gas fuels? I would assume gas runs hotter. For the slower wear with gas makes sense. L

Of course, the mechanic in me hates the idea of brake cylinder hone, but it’s better than nothing for helping to seat the ring. Just limit its use only in making the surface rough.
Unlike a proper hone, like Sunnen or Pemamo for example, it’s not a precision tool. A real hone would also improve the bore geometry, brake cylinder hone does quite the opposite the more you use it.
I must say that to remind that there is also a correct way to do things. That saves time and makes the end result more predictable, and at least in my case, even competitive with other technologies.
But if you have a stock of aftermarket (or even original) rings, the least you can do to ease the running in is to push the ring in cylinder without the piston. Using a bright backlight and trained eye you can easily see which one has the best contact with cylinder wall. L

If your cylinder hone is a ball hone, it will ruin the cylinder. A 3 shoe spring hone is not much better. Even if you use a Sunnen hone you will make the Bore too big before you clean up the worn area. When re-ringing a used cylinder you can use a small piece of 800 paper on your finger with oil to scuff the worn area up around top dead center to help mate the ring. All you want to do is change the surface finish as the piston fit will probably be on the loose side.

MM

I have several engines, some new (un-run) and some used. I will refrain from using any sort of hone unless I have ring seating issues and note that they are to be used sparingly. Also the idea of placing a ring only in the bore and checking for contact is something that I didn't know about but sounds a great idea in eliminating any possibly badly made rings. Thank you all for the help.