Go Back  Offshoreonly.com > General Discussion > General Boating Discussion
Question about planing devices >

Question about planing devices

Notices
General Boating Discussion

Question about planing devices

Thread Tools
 
Old 01-12-2011 | 08:58 AM
  #1  
Thread Starter
Registered
 
Joined: Jul 2007
Posts: 21
Likes: 0
Default Question about planing devices

I picked up a 221 Liberator at the end of the boating season last year and only used it a couple of times. It has a 468 Chevy and King Cobra outdrive. The previous owner installed a large fin on the drive to get it to plane quicker for skiing with his kids. The boat comes up on plane very quickly. I don't use the boat for skiing. Does the fin detract from the boats higher speed performance?
3birds is offline  
Reply
Old 01-12-2011 | 09:07 AM
  #2  
Knot 4 Me's Avatar
Registered
20 Year Member
 
Joined: Jun 2005
Posts: 8,407
Likes: 797
From: Central IL
Default

Ditch the fin and install trim tabs if planning becomes an issue. You can use Marine Tex to fill the holes on the outdrive.
Knot 4 Me is offline  
Reply
Old 01-12-2011 | 09:28 AM
  #3  
Brad Zastrow's Avatar
Registered
20 Year Member
 
Joined: Jun 2001
Posts: 2,303
Likes: 109
From: McHenry, Illinois
Default

I am not sure I agree. Tabs would be better for sure, but drag race outboard boats all use planning fins on the drive. At higher speed they are completley out of the water and I do not think they would slow you down at all. I think a small boat like a 22' it would not be a problem.
Brad Zastrow is offline  
Reply
Old 01-12-2011 | 09:33 AM
  #4  
Registered
 
Joined: Oct 2005
Posts: 5,825
Likes: 612
From: Clarkston, Michigan
Default

You have a 22' boat with a 468 CID Chevy and it needs a planing aid? I don't think so. Take it off now before anyone else sees it.
thirdchildhood is offline  
Reply
Old 01-12-2011 | 10:13 AM
  #5  
Registered
 
Joined: Jan 2009
Posts: 224
Likes: 0
From: Royal Oak, MI
Default

If you don't plan on using the boat for any water sports I would ditch it. The purpose is to get the boat on plane faster and keep it on plane at slower speeds for skiers.

I don't think it would negatively effect the performance, though.
Cousineau181 is offline  
Reply
Old 01-12-2011 | 10:40 AM
  #6  
US1 Fountain's Avatar
Ginger or Mary Ann?
25 Year Member
Charter Member
 
Joined: Oct 2000
Posts: 11,030
Likes: 9
From: L
Default

Originally Posted by 3birds
I picked up a 221 Liberator at the end of the boating season last year and only used it a couple of times. It has a 468 Chevy and King Cobra outdrive. The previous owner installed a large fin on the drive to get it to plane quicker for skiing with his kids. The boat comes up on plane very quickly. I don't use the boat for skiing. Does the fin detract from the boats higher speed performance?
Run it, remove the 4 bolts to remove the fin, do a back to back test run.
__________________
Some people are like Slinkies - Not really good for anything, but they
bring a smile to your face when pushed down the stairs.
US1 Fountain is offline  
Reply
Old 01-12-2011 | 10:41 AM
  #7  
Knot 4 Me's Avatar
Registered
20 Year Member
 
Joined: Jun 2005
Posts: 8,407
Likes: 797
From: Central IL
Default

Originally Posted by Brad Zastrow
I am not sure I agree. Tabs would be better for sure, but drag race outboard boats all use planning fins on the drive. At higher speed they are completley out of the water and I do not think they would slow you down at all. I think a small boat like a 22' it would not be a problem.
Agree it should not affect high speed performance. I just hate seeing these things on any boat. I should have stated such.
Knot 4 Me is offline  
Reply
Old 01-12-2011 | 10:45 AM
  #8  
Ted G's Avatar
Charter Member
20 Year Member
Charter Member
 
Joined: Jan 2001
Posts: 7,663
Likes: 2
From: Edgerock Baby!!
Default

It will actually scrub about 2-3 mph off on top speed and they exert huge forces on the cavitation plate and cause them to break. O your boat with that much power you may not see as much of a speed drop, but on a 40-50 mph I have seen as much as 3 mph more with it off. And of course having the cavitation plate welded back on is always a joy too

Lose it, you'll be happy. Fill the holes with Marinetex or epoxy as someone else said.
__________________
Chesapeake Bay Powerboat Association
www.cbpba.com
Ted G is offline  
Reply
Old 01-13-2011 | 08:07 AM
  #9  
Thread Starter
Registered
 
Joined: Jul 2007
Posts: 21
Likes: 0
Default

I'll pull it off and fill the holes. Worse case is to put it back on if needed. I also think I can go a larger prop.
3birds is offline  
Reply
Old 01-13-2011 | 09:26 AM
  #10  
Registered
 
Joined: Oct 2005
Posts: 5,825
Likes: 612
From: Clarkston, Michigan
Default

Originally Posted by 3birds
I'll pull it off and fill the holes. Worse case is to put it back on if needed. I also think I can go a larger prop.
Good call. Those things belong on 4 banger Bayliners and such that can't get on plane without some help! You can always have two props; A power prop and a top end prop.
thirdchildhood is offline  
Reply

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 On
Pingbacks are On
Refbacks are On



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.