pitch x rpms
----------------- = speed x efficiency = true speed
1056 x gear ratio

1056 is just a conversion factor to get the numbers into MPH.


--
Tony
my boats at http://t.thomas.home.mchsi.com

"Short Wave Sportfishing" wrote in message
...
On Mon, 30 Aug 2004 00:30:40 GMT, "Tony Thomas"
wrote:

The numbers don't add up.
The 4 blade must have been a 24 pitch prop. Otherwise you would have to
turn 6200 rpms w/ a 21 to get that speed.

Assuming the 4 blade is a 24 pitch prop then that should be about your
best
performance w/ this rig.
You could drop down to a 22 and get a few more rpms which will help w/
the
hole shot but it will slow you down on top end.

Help me out here.

How, exactly, is speed/rpm/pitch figured?

Take care.

Tom

"The beatings will stop when morale improves."
E. Teach, 1717