Announcement

Collapse
No announcement yet.

Bravo III Drive.

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

    #76
    Thanks for all the input, next you would like my bank No. right Reading Bams info. the B III was designed for 2500 RPM but has gone through upgrades, so reading on it tells me to use the highs pitch for the gear ratio, So next is to talk to Hill Marine - prop seller as to what is the best RPM performance for there props! then we will hold a POOR BOY collection to get the right gears, Rick I know will help. Lineman I know of the shop in Texas but don't know how much marine info is there. The preformats graph is steep sweet spot is 2800 to 3000 I have 2 trucks with that Eng. Red line 3600, so on with the education process. On a cooler Note, had to scramble yesterday to winterize the boat- weather Today 65H in the morning 37 by Mon. High 30 Low 16 it is TOO Soon.
    Slightly modified 2859 6.5 Diesel Bravo III X drive
    96 Dodge 5.9 5 speed Gear vender OD.

    Comment


      #77
      Fritzman, as I understand it, the engineers decide upon a final drive reduction based on the engine's horse power, torque and idea engine cruising RPM for a given hull.
      The OEM specified WOT RPM is used to determine if all is working correctly (not to be sustained for any duration), and is also used as part of the equation to determine the final reduction.
      More importantly will be your engine's ideal cruise RPM.

      If you know what the ideal cruise RPM will be, you can then determine which final drive reduction will turn the prop shafts at the desired RPM.
      In other words, if your engine's "sweet spot" is let's say 3,000 RPM, then you would do the math to determine the necessary over-all or final gear reduction that will spin the prop shafts at the desired RPM.
      Once that is known and installed, you can then experiment with a few different prop pitches.


      .
      Rick E. Gresham, Oregon
      2850 Bounty Sedan Flybridge model
      Twin 280 HP 5.7's w/ Closed Cooling
      Volvo Penta DuoProp Drives
      Kohler 4 CZ Gen Set

      Comment


      • 2850Bounty
        2850Bounty commented
        Editing a comment
        Ooops, that should have read: ................ based on the engine's horse power, torque and "ideal" engine cruising RPM for a given hull.

      #78
      Thank you Rick I am getting the picture, will know more after visiting with Hill Marine as to best RPM for there props.
      Slightly modified 2859 6.5 Diesel Bravo III X drive
      96 Dodge 5.9 5 speed Gear vender OD.

      Comment


        #79
        Just a little up date, during the Holidays, I am allowed in to the shop with the boat So yes I am going to change to a 181:1 ratio, but I concentrated on a bit of F.G. repair and changing the intake for more air, and eliminated the muffler all to boost power.
        Slightly modified 2859 6.5 Diesel Bravo III X drive
        96 Dodge 5.9 5 speed Gear vender OD.

        Comment


          #80
          Fritz, I hope it turns out to be the correct ratio for your new power plant.
          Fingers crossed for you dude 🤞 😉
          Dave
          Edmonds, WA
          "THE FIX"
          '93 2556 5.7 Bravo II 2.0:1 18 1/4x19 P
          (.030 over-Vortec top end-part closed cooled)
          The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
          Misc. projects thread
          https://www.baylinerownersclub.org/f...56-gctid789773

          Comment


            #81
            Dave, thanks for your support .
            Slightly modified 2859 6.5 Diesel Bravo III X drive
            96 Dodge 5.9 5 speed Gear vender OD.

            Comment


              #82
              OK I have a slight problem, searching drive ratio on my old drive Bravo II with 350 Chevy. 260 HP. where can I find that?
              Slightly modified 2859 6.5 Diesel Bravo III X drive
              96 Dodge 5.9 5 speed Gear vender OD.

              Comment


                #83
                Supposed to be stamped on the input yoke but I had nothing there on mine. Ensure the shift cable jaws are out and open, this will have the drive engaged in forward gear. Now count the number of input shaft revolutions in takes to rotate the prop shaft one time and that will bee the ratio.
                Dave
                Edmonds, WA
                "THE FIX"
                '93 2556 5.7 Bravo II 2.0:1 18 1/4x19 P
                (.030 over-Vortec top end-part closed cooled)
                The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
                Misc. projects thread
                https://www.baylinerownersclub.org/f...56-gctid789773

                Comment


                  #84
                  Thanks Dave, drive is in cold storage packed under a pile in a different shed, I am considered a pack rat so just looking for a simper answer.
                  Slightly modified 2859 6.5 Diesel Bravo III X drive
                  96 Dodge 5.9 5 speed Gear vender OD.

                  Comment


                    #85
                    Fritzman, Dave's suggestion to determine the ratio is right on.
                    However, there is a small catch to it.

                    The cone clutch sliding sleeve oiling groves are designed to hold oil and then allow the oil to dissipate as friction begins to occur.
                    This cushions the gear engagement as to make a smooth transition.

                    When you start rotating the main drive gear, there may be a slight lag before the sliding sleeve and gear cup lock up.
                    You will know when they do.

                    Once you start rotating the main drive gear, don't let up.... keep going.
                    If you let up, you will be starting over.

                    Also, hold some resistance against either prop shaft while you rotate the input shaft (i.e, main drive gear).



                    If you have the 1.81:1 reduction, the input shaft will turn one full revolution, plus approx 8/10 of a second turn, while the prop shaft makes only one revolution.




                    Rick E. Gresham, Oregon
                    2850 Bounty Sedan Flybridge model
                    Twin 280 HP 5.7's w/ Closed Cooling
                    Volvo Penta DuoProp Drives
                    Kohler 4 CZ Gen Set

                    Comment


                      #86
                      Thank you Rick.
                      Slightly modified 2859 6.5 Diesel Bravo III X drive
                      96 Dodge 5.9 5 speed Gear vender OD.

                      Comment


                        #87
                        Different question but related, some time back Norton Rider posted a picture of a ? 2858 or ? with the same engine as I am dealing with so ! it would be great to find boat and or owner to learn drive and prop information still struggling but will change gears to 181:1 but have ) prop information???
                        Slightly modified 2859 6.5 Diesel Bravo III X drive
                        96 Dodge 5.9 5 speed Gear vender OD.

                        Comment

                        Working...
                        X