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posted to rec.boats
Injam
 
Posts: n/a
Default I'm trying to understand propellers

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


wrote in message
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.