Announcement

Collapse
No announcement yet.

prop tunnels: explanation of what they are:

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    prop tunnels: explanation of what they are:

    A few members are wondering what "tunnels" are.
    Well- tunnels;s are an extension of the prop pockets/tunnels for the propellers on the 38XX series, I do not know if the ones I fabricate fit the 38XX series though as well as the 43' series.
    What they do is extend that tunnel 18 inches, the result is: the rooster tail at your stern is largely removed and pushed down,translating to forward push.
    This modification should give more fwd. thrust and little or no rooster tail.
    The first set I sold the owner stated an increased in speed about 1.5 knots, there should be a corresponding decrease in fuel consumption, buy I will be testing that this summer in Alaska with diesels and with my gas powered 3870.
    If anyone has any questions on the modification please contact me.
    boatworkfl on BOC
    I will give you my email and phone number, yes I do build these!
    Last edited by boatworkfl; 12-06-2017, 05:03 PM.
    Pat says: DO-IT-RIGHT THE FIRST TIME!

    Bayliner 3870 "ALASKA33)
    Twin 350 GM power
    Located in Seward, AK
    Retired marine surveyor

    #2
    39's don't have prop pockets...
    Brad & Michelle
    Jet & Maverick
    1993 3688 "the Kraken"
    Hino W06 250HP
    14' Avon RIB, 50hp Tohatsu
    Moored at Shelter Bay
    LaConner, WA

    Comment


      #3
      Originally posted by Dirtyface View Post
      39's don't have prop pockets...
      My error, I meant to type 38 series.
      Pat says: DO-IT-RIGHT THE FIRST TIME!

      Bayliner 3870 "ALASKA33)
      Twin 350 GM power
      Located in Seward, AK
      Retired marine surveyor

      Comment


        #4
        Is there anyone that still makes these for 4588's?
        Yep, my 4588 Bayliner IS my happy place :whistle:

        Comment


          #5
          Originally posted by Foster View Post
          Is there anyone that still makes these for 4588's?
          Do the 4588's have tunnels/prop pockets?
          Pat says: DO-IT-RIGHT THE FIRST TIME!

          Bayliner 3870 "ALASKA33)
          Twin 350 GM power
          Located in Seward, AK
          Retired marine surveyor

          Comment


            #6
            Originally posted by boatworkfl View Post

            Do the 4588's have tunnels/prop pockets?
            Yes - they are very much alike the 38 and 45 tunnels. We owned an 86 - 38 and two 45's.
            Northport NY

            Comment


              #7
              Originally posted by smitty477 View Post

              Yes - they are very much alike the 38 and 45 tunnels. We owned an 86 - 38 and two 45's.
              The actual measurements-wide at the top of the trim tabs and the height up from that line not including the rudder recess.
              I did not think to measure the 45's in the boatyard in Seward AK
              I think I will call Dave at the boatyard in Seward and see if I can get those measurements.
              Are the 45's tail heavy like the 38XX Bayliners?
              If they fit it still should help get rid of that rooster tail which should translate to FWD thrust.
              Pat says: DO-IT-RIGHT THE FIRST TIME!

              Bayliner 3870 "ALASKA33)
              Twin 350 GM power
              Located in Seward, AK
              Retired marine surveyor

              Comment


                #8
                Yep, the 45 has tunnels, that's why we bought it, for the slight smaller draft and the hope for a little more speed/distance efficiency.

                My 4588 isn't that stern heavy, mostly due to how we store things on the boat. With the addition of the dink on Weaver davits it will become heavier.

                Thanks for getting measurements to see if the ones you are making will fit.
                Yep, my 4588 Bayliner IS my happy place :whistle:

                Comment


                  #9
                  For those that keep asking about the fuel economy of installing a pair of tunnels: The current feed back is: You should gain about 1.5 to 3 miles per hour, and either eliminate or significantly reduce the rooster tail behind your boat.
                  If you tow a dingy it is a no brainer, over time the fuel savings work out, you also have less stern sag common with Bayliners when running, especially those with generators or a dingy on the stern.
                  I will be buying a new trailer from Sam's club and will be building a new box for moving my goods and supplies starting mid April.
                  If you are interested in a pair of tunnels do not wait until spring, I will be on my way to Alaska until mid Sept.
                  I will take 1 extra pair to Alaska and will try to have 2 pair available between now and then, for the most part, I will make these to order.
                  I have a permanent retirement income and I do this to stay busy, stay busy and stay young! At 73 it is still working for me!

                  Pat boatworkfl
                  Pat says: DO-IT-RIGHT THE FIRST TIME!

                  Bayliner 3870 "ALASKA33)
                  Twin 350 GM power
                  Located in Seward, AK
                  Retired marine surveyor

                  Comment

                  Working...
                  X