ORIGINAL: Bax

The Hanno isn't really a BPA-type of engine. It was designed to turn an APC 12 x 12 prop at about 9,600 RPM when on the pipe. The pipe was required because that's how the engine was ported. The Hanno was designed for the early type of turnaround pattern that replaced the old ballistic pattern.

Ballistic-types needed a high-revving engine to enable the speed.

For late-60's-style pattern, then you might be able to do OK with a Hanno, but, again, the pipe is a necessity for the Hanno's performance.

If you want to compete in old-style pattern, then the O.S. .65 LA may not be an option, but if you're wanting to fly the older designs as they flew back then, then the .65 LA is a very viable choice. Keep a Kaos, Quik Fli, New Orleanian, Eyeball, and so on, all within their intended weight limits, and you'll have quite a nice-flying bird.