Reply
 
Thread Tools Display Modes
 
Old 10-07-2014, 01:09 AM   #1
Guru
 
drb1025's Avatar
 
City: Bellevue, WA
Country: USA
Vessel Name: Fiddler
Vessel Model: DeFever 46
Join Date: Oct 2012
Posts: 501
Props

Having just filled up the tanks, fuel and water, I decided to take it fully loaded at WOT to see if the engines would reach their rated 2,600 rpm (JD 4045). The port engine topped out at exactly 2,600 but the stbd only made it to 2,535. My question to you prop experts out there is whether the shortfall is enough to merit changing the pitch on the stbd prop, or if its close enough. I usually cruise at 7.5 to 8 kts, or 1,600- 1,900 rpm, and usually with half the load.
__________________
Advertisement

drb1025 is online now   Reply With Quote
Old 10-07-2014, 01:17 AM   #2
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
Might want to pose your question to a reputable and experienced prop shop. We used Kruger & Sons near the Seattle Ship Canal.
__________________

Marin is offline   Reply With Quote
Old 10-07-2014, 02:22 AM   #3
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
Assuming the tachos are correct, the shortfall is .025%. Close enough?
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 10-07-2014, 04:54 AM   #4
Guru
 
drb1025's Avatar
 
City: Bellevue, WA
Country: USA
Vessel Name: Fiddler
Vessel Model: DeFever 46
Join Date: Oct 2012
Posts: 501
Props

65/2600= .025, or 2.5%. Is that within an acceptable tolerance?
drb1025 is online now   Reply With Quote
Old 10-07-2014, 05:42 AM   #5
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 7,573
Quote:
Originally Posted by drb1025 View Post
65/2600= .025, or 2.5%. Is that within an acceptable tolerance?
Not sure, but my math is certainly not acceptable. Never was. Apologies.
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 10-07-2014, 05:43 AM   #6
Guru
 
Tidahapah's Avatar
 
City: Mooloolaba
Country: Australia
Vessel Name: Tidahapah
Vessel Model: Bert Ellis Timber motor cruiser
Join Date: Oct 2007
Posts: 1,779
Before doing anything and personally I don't think it is worth it with such a small discrepancy I would check both engines with a quality digital tacho.
Cheers
Benn
__________________
"When I die I hope my wife doesn't sell my toys for what I told her I paid for them"
Money: It's made round to go round , not flat to stack.
"Get out and do it"
Tidahapah is offline   Reply With Quote
Old 10-07-2014, 06:53 AM   #7
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,531
Forgetabout it.

Your cruise RPM , at over 500rpm down will never tax the engine .
FF is offline   Reply With Quote
Old 10-07-2014, 08:48 PM   #8
Senior Member
 
City: G
Country: usa
Join Date: Feb 2014
Posts: 142
i certainly would not touch the props from those readings, sounds close to perfect to me
__________________

stone beach is offline   Reply With Quote
Reply

Thread Tools
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 12:04 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012