With a fresh battery in the tach, I did some more running today. These are both used engines that I cleaned up and restored. I'm sure I could trim a bit more off the headers and gain a bit more, but I'm very impressed with what I got. Readings are peak. I would back off a few clicks for flying.

Rossi RE with old-style Mac's Muffled Pipe:

81°
Powermaster GMA 5% nitro/22% oil
OS #8 plug
APC 11x8
14,164
10.11lbs static thrust
2.06hp
93.2mph

Webra 1030 RE with new-style Mac's Muffled Pipe:

81°
Powermaster GMA 5% nitro/22% oil
K&B 1L plug
APC 11x8
14,420 WOW!!!
10.48lbs static thrust
2.18hp
94.9mph

The Rossi was fitted with an OS #7L carb and the Webra has a Dynamix. The #7L was leaking a bit around the needle valve, so it needs a new O-ring. The seal against the case might have been leaking a bit, too, since it didn't want to shut down. The Dynamix is maybe the nicest carb I've ever used. Both the low speed and high speed needles have a very broad range. Transition is great with no loading up in the midrange. No problem at all with fuel draw at any setting. Though, the fact that my test stand has an 8oz tank might be helping that a bit.

I think the Webra absolutely deserves to have a plane built for it.

I also ran my Super Tigre Bluehead .40 with a pipe, but I'll put that data in the Tach forum.

David