Reply
 
Thread Tools Search this Thread Display Modes
 
Old 05-19-2017, 11:24 PM   #1
TF Site Team
 
Baker's Avatar
 
City: League City, Tx
Country: Texas
Vessel Model: Carver 356
Join Date: Oct 2007
Posts: 6,264
Pop quiz hotshot...prop pitch

I will admit I have always been baffled by the terminology of prop pitch. We talk about it in inches. My prop is 24 inches of pitch and there is nothing that I can see while looking in the pitch plane that represents 2 feet(24 inches). I did learn what it meant yesterday....finally!!! There are likely many people on here that know what it means. But I asked around my part of the world and many otherwise very knowledgeable people could not explain it.

Can you???
__________________
Advertisement

__________________
Prairie 29...Perkins 4236...Sold
Mainship Pilot 30...Yanmar 4LHA-STP...Sold
Carver 356...T-Cummins 330B
Baker is offline   Reply With Quote
Old 05-19-2017, 11:31 PM   #2
Guru
 
rochepoint's Avatar
 
City: Sidney BC
Country: Canada
Vessel Name: RochePoint
Vessel Model: 1985 Cheer Men PT38 Sedan
Join Date: Apr 2009
Posts: 1,467
Theoretical distance it would travel in one revolution with no slippage........
__________________

__________________
Cheers Mike Barge
RochePoint
Sidney, British Columbia
Yes, I have my "AnchorRight"
rochepoint is online now   Reply With Quote
Old 05-19-2017, 11:43 PM   #3
Guru
 
AusCan's Avatar
 
City: Adelaide
Country: Australia
Vessel Name: Kokanee
Vessel Model: Cuddles 30 Pilot House Motor Sailer
Join Date: Jul 2012
Posts: 2,890
Quote:
Originally Posted by rochepoint View Post
Theoretical distance it would travels in one revolution with no slippage........
That it!

I get my head around the "no slippage" term by thinking of the prop slowly turning in a semi-solid like butter.
AusCan is offline   Reply With Quote
Old 05-20-2017, 12:39 AM   #4
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 12,332
Rotate your prop through jello for one full revolution and the pitch is the distance it traveled through the jello.
__________________
My boat is my ark. It's my mobile treehouse and my floating fishing cabin. It's my retreat and my respite. Everyday I thank God I have a boat! -Al

@DeltaBridges - 25 Delta Bridges in 25 Days
FlyWright is online now   Reply With Quote
Old 05-20-2017, 02:54 PM   #5
TF Site Team
 
Baker's Avatar
 
City: League City, Tx
Country: Texas
Vessel Model: Carver 356
Join Date: Oct 2007
Posts: 6,264
WoooHooo!!!! Jello shots for all!!!
__________________
Prairie 29...Perkins 4236...Sold
Mainship Pilot 30...Yanmar 4LHA-STP...Sold
Carver 356...T-Cummins 330B
Baker is offline   Reply With Quote
Old 05-20-2017, 09:21 PM   #6
Senior Member
 
greysailor's Avatar
 
City: Matagorda Bay
Country: Republic of Texas - USA
Vessel Name: Salty
Vessel Model: 2005 Defever 44
Join Date: May 2013
Posts: 192
Ha! John, if you were a prop job crop duster instead of a jet jockey, you might have known that answer! ��
greysailor is offline   Reply With Quote
Old 05-21-2017, 12:02 AM   #7
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 12,332
Quote:
Originally Posted by greysailor View Post
Ha! John, if you were a prop job crop duster instead of a jet jockey, you might have known that answer! ��
ROFLMAO!
__________________
My boat is my ark. It's my mobile treehouse and my floating fishing cabin. It's my retreat and my respite. Everyday I thank God I have a boat! -Al

@DeltaBridges - 25 Delta Bridges in 25 Days
FlyWright is online now   Reply With Quote
Old 05-21-2017, 12:23 PM   #8
TF Site Team
 
Baker's Avatar
 
City: League City, Tx
Country: Texas
Vessel Model: Carver 356
Join Date: Oct 2007
Posts: 6,264
Quote:
Originally Posted by greysailor View Post
Ha! John, if you were a prop job crop duster instead of a jet jockey, you might have known that answer! ��
But they have variable pitch propellers....
__________________
Prairie 29...Perkins 4236...Sold
Mainship Pilot 30...Yanmar 4LHA-STP...Sold
Carver 356...T-Cummins 330B
Baker is offline   Reply With Quote
Old 05-21-2017, 12:37 PM   #9
Senior Member
 
greysailor's Avatar
 
City: Matagorda Bay
Country: Republic of Texas - USA
Vessel Name: Salty
Vessel Model: 2005 Defever 44
Join Date: May 2013
Posts: 192
Quote:
Originally Posted by Baker View Post
But they have variable pitch propellers....
Yep....but that just determines how much Jello they cut per revolution! Break out another round of Jello shots!
Sure is some nice looking "boat bling" you have there...should be good for a little extra speed and fuel economy.
greysailor is offline   Reply With Quote
Old 05-21-2017, 12:42 PM   #10
Guru
 
Ski in NC's Avatar
 
City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 5,354
What makes pitch tricky to measure is that as you get further from the center, the blade angle changes. The blade is curved so with each say 10deg of rotation, the amount of advance is constant from hub to tip. So blade angle changes as you get further from the hub. Need a jig of some sort to measure pitch.
Ski in NC is offline   Reply With Quote
Old 05-22-2017, 02:53 PM   #11
TF Site Team
 
Baker's Avatar
 
City: League City, Tx
Country: Texas
Vessel Model: Carver 356
Join Date: Oct 2007
Posts: 6,264
I can tell I got a little more performance out of them. Maybe a knot or knot and a half. Funny thing is i didn't lose that much RPM. I can still get 2950 on a 2800 RPM engine. And I just started an 8 day trip so this bitch is loaded up. Oh well. I at least know that I'm not working her too hard.
__________________
Prairie 29...Perkins 4236...Sold
Mainship Pilot 30...Yanmar 4LHA-STP...Sold
Carver 356...T-Cummins 330B
Baker is offline   Reply With Quote
Old 05-22-2017, 04:07 PM   #12
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 16,080
I agree John,
Let'um sing and w/o too much load.
Like a truck climbing a hill. Work'in like they could do it forever.

Ski,
There are props designed to have the same pitch all around a given diameter. Like my MP prop from Michigan. The "MP" stands for "machined pitch". I like my old skewed blade prop better. Looking for an excuse to haul the boat and stick it back on. Kinda thin though. Been ground uppon by too many "prop men" .. probably.
__________________

__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 01:40 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012
×