The Magnum 1.80 and other engine like it (e.g. OS BGX-1) were really designed to compete with the weedwacker gas engines. As such, they are typically heavy and not exactly powerhouses. I know this is not what you want to hear, but they are best suited for laidback big-winged floaters that the typical weedie engines or the Zenoahs would fly nicely.

Any of the 1/4scale aerobats (H9 CAP232, GP Giles, etc.) are really not good matches for this type of engine. Perhaps a Stinger 120?