Tom,
Nothing easier than that. I used the engine of a Nakajima A6 Rufe Floatplane from Trumperter. The scale is 1/24. This engine is also in the Zero plane from Trumpeter. As an alternative you could also use the engine of Focke Wulf FW 190 from Trumpeter or Airfix, North-American P47D Thunderbolt from Kinetic or Revell's 1/28 WW1 air planes. Revell's engines are single row engines while the others are double row engines.