Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Given that the engine is now more than 145 years old, it is hard to say of the timing is still set correctly which is critical to smooth operation on water. Steam and air are more forgiving. Steam inlets closing early is an efficiency measure applied to let the expanding steam continue to work without putting in steam not needed. Steam inlets opening early can help provide a padding effect for steam and air engines. Water motors do not have the luxury of expansion. Both air and steam under pressure will expand back to atmospheric pressure quickly and provide that extra efficiency. The water motors would also not likely ever run as fast as a steam engine is capable of. I believe that for power, the pressure applied by air, water, and steam should all give the same torque at the same level. I don't believe a water motor with reciprocating pistons would ever be capable of high speed high powered operation. These were designed to run off a municipal water supply or off the water pressure from a cistern in the attic of a taller house.