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View Full Version : A Propellor Theory..



gcarter
06-27-2005, 04:10 PM
that goes something like this;
How about a cruising prop. I haven't heard anyone comment on something like this. My engine seems to develop a lot of torque, and seems to run a very high cruise speed with a 25" prop. I seem to be able to cruise about 50 MPH at about 3000 RPM. Of course it kills the top end, only good for about 60 MPH @ 41-4200 RPM. But if you were trying to move your boat 100 miles or so, it might be interesting. It's definately out of the carb secendaries, your turning a lower engine speed so it should be kinder to the engine.
What do you think?

MOP
06-27-2005, 05:18 PM
There is a lot of sense in what you are thinking, over the years I have been able to play prop games with a ton of customers boats. As long as you can keep the engine in its proper operation RPM range go for higher pitch for long cruises, most manufacturers recommend 42 to 4600 in single apps twins can be run a bit less. Give up some hole shot and gain fuel economy.

Phil