Turn Fin?
+ Reply to Thread
Results 1 to 6 of 6

Thread:
Turn Fin?

  1. #1
    Frst Round Runnerup Hondog's Avatar
    Join Date
    Jan 2008
    Location
    Turlock, CA
    Posts
    334

    Default Turn Fin?

    I have a Sleekcraft 21 Jr Executive (Day Cruiser)with a 5.7ltr and Alpha 1 outdrive. I find that the low speed manueverability is pretty poor. (it pretty much goes where it wants if there is any crosswind) I have thought about installing a turn fin. anybody have any thoughts on this idea.

    I am not a rookie boater, had I/Os, outboards, jets, and for the last 28 yrs a Hondo runnerbottom. I can do the work, just wondering if anyone has done this before and how it worked out.

    Thanks
    Bob

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Senior Member Bubbletop409's Avatar
    Join Date
    Jan 2008
    Location
    Castro Valley, Ca.
    Posts
    1,394

    Default

    Not sure what a turn fin is on an OD. Low speed wondering is usually slop in the rack/pinion cable type steering typically found in low perf. OD steering assembly's.
    Larry

    62 Bel-Air 409

    260 Eagle XP HP500EFI

    2016 Corvette Z51

    79 Cole TR-2 Sunset Racecraft 565 (RIP Tracy)

    Remember in November

    Well done USN Seal Team 6

  4. #3
    Senior Member f_inscreenname's Avatar
    Join Date
    Dec 2007
    Location
    Pasadena, Maryland
    Posts
    1,527

    Default

    Hard to explain but you want the boat to steer off of the nose of the drive and not further up the boat. Theoretically when running all you want is the prop in the water and the very end of the transom for side to side stability and the rest of the boat is just along for the ride. A fin further up the hull will give it a tendency to hook at higher speeds.

    But I think you are experiencing what Bubbletop409 said and pretty much all steering set ups will do it up to external hydraulic and hydraulic are not cheap.
    A winner is just a loser that got up and did it one more time.
    1959 Biesemeyer - 4pt Hydro Drag - 2013 ACBS Winner - Best Race Boat
    1966 Donzi 16
    1967 Nova Marine - SuperNova24 - ACBS Winner - 2012 Best Race Boat - 2016 Peoples Choice & Best Non Wood
    1972 John Allmand - Nova 19
    1982 PolarKraft -Jonboat - Crab Killer

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    Senior Member
    Join Date
    Jun 2009
    Location
    Discovery Bay, CA
    Posts
    3,362

    Default

    I agree that it sounds like you have steering system problems. A turn fin will not help solve the handling problem you're describing.

  7. #5
    It's what we do BDMarine's Avatar
    Join Date
    Dec 2007
    Location
    El Monte
    Posts
    723

    Default

    I do not recommend a turn fin with a sterndrive. It will create handling problems and not solve the wandering at idle. A cross wind will move any boat at idle. I agree though, that you probably have play in the gimbal ring and/or steering arm at the steering pin. Many boats wander at idle speeds, especially small block/Alpha combinations. They usually have low gear ratio's and small props resulting in low propeller thrust at idle speeds.
    http://www.performanceboats.com//signaturepics/sigpic837_1.gif
    B & D Marine Performance
    El Monte, Ca.

  8. #6
    Frst Round Runnerup Hondog's Avatar
    Join Date
    Jan 2008
    Location
    Turlock, CA
    Posts
    334

    Default Thanks for response

    I had some concerns that there might be some kind of negative reaction, that is why I posted this, even though this boat rarely sees over 30MPH and not enough oomph to pull beyond 43MPH on it's best day.
    Not a steering gear issue(as I said I am not a newby) My concern is not about wandering at idle speed, didnt explain myself very well.
    When in tight quarters, like a marina, if you begin a turn, especially in reverse, it will not respond to the helm when I want to straighten out the way i would like. Instead it will "dogwalk" and continue in direction it was swinging in when I began the turn (zero "bite" in the front of the hull to correct/pivot off). It requires me drive it at idle speed sort of as if it were a jet and apply significant throttle to change it's direction. This can be challenging in a tight marina.
    It could be that i have been driving a v-drive for so long that i have forgoten that this is the nature of the beast. I can live with it, was just looking for a way to possibly improve if i can.

    I can and did imagine that the center fin could possibly cause a tendency to overreact and hook at speed, that is why I posted this question.

    Thank you again for the input.................Bob
    Last edited by Hondog; 11-06-2014 at 02:00 PM.

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Please select your insurance company (Optional)

Log-in

Tags for this Thread

Digg This Thread

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •  
 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95