I have run my zdz 100 on my own mufflers which are made from aerosol cans and the engine ran fine. The cans are 9"longx2.25dia with a 1"dia. header and 1/2"dia. outlet. I am getting 6000rpm's on 40/1 synthetic with a 26x10 menzs standard after a 1/2 hour run on it. I didn't run it for more than a few seconds at full throttle since it's not broken-in yet, but it looks like it will be a very good engine. It will probably gain 4 to 500 rpm's after a proper break-in as my 80"s did and I think It should turn a 27x10 Menzs/S without any problems. The engine runs very smooth and cool. It has a very good throttle response and should have good torque. I have also fitted it into my H9 Sukhoi and hope to fly it when spring time comes. Don't forget guys, this is a long stroke engine so this means they run lower rpm's but give more torque. I hope to run it more as soon as the temperature warms up a little and I will post my findings when I can.
I would like to here about your readings Dick if you don't mind. I am very interested in what you come up with and what your set-ups are as well.
Good luck and have fun !!