RE: Performance of MVVS/Evolution 26 gas
Keane,
MVVS do post some [link=http://mvvs.cz/mvvs%2026SP.html]benchmark numbers for the 26 cc engine[/link].
As you can see, with the #3266 tuned-pipe, this engine spins a 16x10 prop and an 18x8 prop, at about the same RPM.
For the 18x8, there is also a number with the #3270 Pitts style side muffler, which is ~900 RPM lower than the piped figure.
The same number is what you would expect for the 16x10 prop.
But do take note; the Mejzlik C/F props, with which these numbers were taken, offer less load than, say, a Bolly wood prop of the same dimensions, but with wider blades...