ORIGINAL: Bosch232
I agree with Bill, see if you can get that engine running better.
Really, the G-26 flies my sopwith quite well.
And I only say that to give you a baseline comparison.
I don't remember what it's tach-ing at, but I'm sure it's in the 7's.
And I agree too. The Quadra 50 /52 wasn't that much of a dog in its day. I can remember when they were mainline engines and I thought they ran quite well though not up to current standards. Here in my area we have several of the B-USA WW1 planes flying very well on various engines that include the US-41 and various Fuji models .... not considered powerhouses either but they fly these planes very well with reasonable vertical performance. Also surprisingly short take off distances.