Yes, but you are talking relatively small engines, low horsepower etc. Neither the engine under discussion or the engine I mentioned fit those criteria, although they are small by ship sizes. Kapanui (30ihp Simpson Strickland Compound 4.5 + 9 * 5.5) has no flywheel, but a large 29 by 31 prop (four large blades), and yet her engine is incredibly smooth, even flat out (400rpm). As a testament to its smoothness, there was a mark on the brass cylinder block cover that showed where the oil can sat all its working life, obviously for many years. I could put the oil can in the same spot and leave it there for weeks if only running in sheltered waters, and it won't come off. Only a big rolling sea or wake with throw it off the engine.
In a smaller engine, a flywheel would be necessary, as shaft and prop are smaller, over 25IHP i doubt they are necessary provided the engine is well balance in the first place.
Daniel
DetroiTug wrote:
I used to believe this as well. After running without a flywheel and with the flywheel, I have concluded that a balanced multi-cylinder engine definitely runs smoother with a flywheel even though one is not needed for rotational inertia. The propshafts we typically run are long and smaller than ship-sized diameter in scale which can twist under torque loading.....
-Ron