You're quite right, making the tunnel would really just be a fun little project. If one isn't doing it for the amusement value as much as for a the possibility of a small performance gain, then it truly might be a waste of time. In such a case, start with a better airframe from the get-go - Matney Zoomer, whatever..

Myself, I figured on doing it just because it is a nod towards what the aircraft really could have been. It goes like snot with a side exhaust engine, and if it is the first aircraft a guy ever flies at these sorts of speeds, it is plenty enough as is! It is not slow, while at the same time it is NOT a 200mph airplane as Weston implies. Except perhaps wound right out in a dive. But 150 and a bit more, yessir.

krkenned: the nice thing about a Jett FISE is that if you crack up the Magnum, you still own a very powerful, durable, and versatile engine that throttles wonderfully and that is well suited to many other projects. The West .50 handles really well and is a bear for power too, but is slightly more limited in prop selection and application - I guess you could say it is a bit more high-strung than the Jett. Can't speak about the Rossi, don't own one.

MJD