So you are saying that the heavier motor would not slip as much as the
lighter one?


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oups.com...

Injam wrote:
Think of it this way.

If I'm screwing a wood screw into a piece of wood and my friend Charley
is
doing the same thing. The wood is the same and the pitch on the screws
are
the same. Screws are identical, but Charley is a lot stronger than I am.
We
turn the screws at the same RPM. Will Charley screw his screw in before
me?


Yes, because Charley is able to apply greater downward pressure on the
screw as he turns it and thereby increase the efficiency, even if the
torque and speed is identical. But that doesn't apply to your boat
example.

The higher HP engine could produce more torque, but the amount of work
being done to turn the prop 6000 rpm is not a variable in your example.
If the prop is turning 6000 rpm and all the other factors are the same
the two boats would travel the same distance per rotation of the prop.

Injam wrote:
So you are saying that the heavier motor would not slip as much as the
lighter one?


No. I'm saying that the greater amount of downward pressure applied
when turning a screw into wood, the more efficiently it drives. Much
different than you boat example.

We're not talking about the "engine" slipping at all. We're talking
about the prop slipping. All props slip. Two props of idential diameter
and pitch will slip the same amount at the same RPM in the same medium.