I don't believe there are very many gaps in power plant sizes beginning with CO2 motors and Cox .010ci through 36 cylinder turbo charged WWII engines. Where Satio and OS leave off, 3W takes over. Where 3W ends, Rotax fills in... and on it goes. There may be some thin spots in the power plant size-line but I'd guess there are very few if any gaps.

3W's largest... http://www.3w-modellmotoren.com/engl...r404.html~main

Rotax's smallest... http://www.rotax.com/en/Engine/2004/...ine.Models.htm


Bill