I should know this, but apparently I'm confused about something.

Therefore an appeal to the group for the following questions.

What is the net effect of increasing diameter with the same pitch?

What is the net effect of increasing/decreasing the pitch with the
same diameter?

I ask because I was discussing props with a friend today and I had
something totally confused.

On Fri, 28 Mar 2008 23:06:32 GMT, Short Wave Sportfishing
wrote:

Therefore an appeal to the group for the following questions.

What is the net effect of increasing diameter with the same pitch?

More thrust, greater prop efficiency (less slip), requires more torque
(horsepower) to maintain the same RPMs, more vibration if tip
clearance is insufficient.

What is the net effect of increasing/decreasing the pitch with the
same diameter?

Greater forward motion with each turn, more slip unless a light easily
driven hull, requires more torque (horsepower) to maintain the same
RPMs.

Either should cause speed to increase by some amount if RPMs can be
maintained.

"Short Wave Sportfishing" wrote in message
...
I should know this, but apparently I'm confused about something.

Therefore an appeal to the group for the following questions.

What is the net effect of increasing diameter with the same pitch?

What is the net effect of increasing/decreasing the pitch with the
same diameter?

I ask because I was discussing props with a friend today and I had
something totally confused.



A friend (who posts here) explained it to me once. But, now I forget.

Eisboch

"Wayne.B" wrote in message
...

On Fri, 28 Mar 2008 23:06:32 GMT, Short Wave Sportfishing
wrote:

Therefore an appeal to the group for the following questions.

What is the net effect of increasing diameter with the same pitch?

More thrust, greater prop efficiency (less slip), requires more torque
(horsepower) to maintain the same RPMs, more vibration if tip
clearance is insufficient.



*That's* what I forgot ..... better prop efficiency with less slip.

Eisboch

On Fri, 28 Mar 2008 20:06:35 -0400, Wayne.B
wrote:

On Fri, 28 Mar 2008 23:06:32 GMT, Short Wave Sportfishing
wrote:

Therefore an appeal to the group for the following questions.

What is the net effect of increasing diameter with the same pitch?

More thrust, greater prop efficiency (less slip), requires more torque
(horsepower) to maintain the same RPMs, more vibration if tip
clearance is insufficient.

What is the net effect of increasing/decreasing the pitch with the
same diameter?

Greater forward motion with each turn, more slip unless a light easily
driven hull, requires more torque (horsepower) to maintain the same
RPMs.

Either should cause speed to increase by some amount if RPMs can be
maintained.

That's what I thought.

Hmmm...

On Fri, 28 Mar 2008 20:15:01 -0400, "Eisboch" wrote:


"Short Wave Sportfishing" wrote in message
.. .
I should know this, but apparently I'm confused about something.

Therefore an appeal to the group for the following questions.

What is the net effect of increasing diameter with the same pitch?

What is the net effect of increasing/decreasing the pitch with the
same diameter?

I ask because I was discussing props with a friend today and I had
something totally confused.

A friend (who posts here) explained it to me once. But, now I forget.

That's my problem. I was talking about props and by the time I
finished the conversation, I was totally confused about something that
I thought I knew. :)

Of course being older than dirt, sometimes 'ya forget stuff 'ya know?

"Short Wave Sportfishing" wrote in message
...


Of course being older than dirt, sometimes 'ya forget stuff 'ya know?

It's a blessing in disguise.


Going to look at a boat tomorrow.

Eisboch

On Fri, 28 Mar 2008 21:11:29 -0400, "Eisboch" wrote:


"Short Wave Sportfishing" wrote in message
.. .


Of course being older than dirt, sometimes 'ya forget stuff 'ya know?

It's a blessing in disguise.

Going to look at a boat tomorrow.

Cool.

Outboards? :)

You hit the rocks sooner(lol).

"Short Wave Sportfishing" wrote in message
...
I should know this, but apparently I'm confused about something.

Therefore an appeal to the group for the following questions.

What is the net effect of increasing diameter with the same pitch?

What is the net effect of increasing/decreasing the pitch with the
same diameter?

I ask because I was discussing props with a friend today and I had
something totally confused.