OK, for those wanting more specifics, it's for an experienced modeller (but not an expert). It will be used on a .40-sized sport plane (perhaps a Big Stik .40 or a Tiger 2) and it will most likely use a 10x6 or 11x6 prop depending on which is more suitable for the engine selected.

Asmund - I haven't found a reliable source for Magnum/SC/ASP engines in the .40 to .52 size range for less than $79.99 plus S&H. Any idea where they can be found for less?