Loading ...
Sorry, an error occurred while loading the content.

engines

Expand Messages
  • tysond99
    Happy Hollidays, I wonder if anyone in this group has experience with outboard jet drives. I have talked to designers who say that it is hard to make an
    Message 1 of 8 , Jan 2, 2004
    • 0 Attachment
      Happy Hollidays,
      I wonder if anyone in this group has experience with outboard
      jet drives. I have talked to designers who say that it is hard to
      make an inboard/jet drive work smoothly because alot of air
      (bubbles) are trapped under the hull and consequently fed to the jet
      pump with a poor result in propulsion. I wonder if outboard jets
      would work better since they can be adjusted for depth independent
      of the hull.
      On the Upper Delaware River where I live I see Carolina skiffs
      going though 6" deep water at 20-30 MPH with 100/+- HP engines on
      their transoms. Imagine how nice this might work on some of the PCB
      sharpie boats.

      Don
    • billfye
      Here is a page full of boats that have been adapted for PWC (personal water craft) jet drive propulsion. Notably, some of Jim Michalak s designs have been
      Message 2 of 8 , Jan 3, 2004
      • 0 Attachment
        Here is a page full of boats that have been adapted for PWC (personal
        water craft) jet drive propulsion. Notably, some of Jim Michalak's
        designs have been adapted.

        http://jetjon.homestead.com/page1.html

        Although in theory, it sounds like it shouldn't work that well, in
        practice it seems to be a really good way to power a boat while
        maintaining the shallowest draft.


        --- In bolger@yahoogroups.com, "tysond99" <tysond99@y...> wrote:
        > Happy Hollidays,
        > I wonder if anyone in this group has experience with outboard
        > jet drives. I have talked to designers who say that it is hard to
        > make an inboard/jet drive work smoothly because alot of air
        > (bubbles) are trapped under the hull and consequently fed to the jet
        > pump with a poor result in propulsion. I wonder if outboard jets
        > would work better since they can be adjusted for depth independent
        > of the hull.
        > On the Upper Delaware River where I live I see Carolina skiffs
        > going though 6" deep water at 20-30 MPH with 100/+- HP engines on
        > their transoms. Imagine how nice this might work on some of the PCB
        > sharpie boats.
        >
        > Don
      • dkb715
        Don, I have a Yamaha 115 HP 4 stroke outboard with a jet that I have mounted on a 19 sled I finished about 2 1/2 years ago. The boat has a modified V hull.
        Message 3 of 8 , Jan 3, 2004
        • 0 Attachment
          Don,

          I have a Yamaha 115 HP 4 stroke outboard with a jet that I have
          mounted on a 19' sled I finished about 2 1/2 years ago. The boat
          has a modified V hull. Some of the other replies were right in that
          you lose about 25 - 30% of your power with the jet. You don't want
          the water intake hanging down significantly below the back of the
          transom (mine is pretty much even with it). The whole idea behind
          the jet is to allow you to travel in shallow water. It would also
          produce a lot of drag.

          The jet is also a real pig at slow speeds. Maneuverability is a
          major challenge, especially when docking. The inboard jets seem to
          be much better because they have a bigger bucket.

          Dave B


          --- In bolger@yahoogroups.com, "tysond99" <tysond99@y...> wrote:
          > Happy Hollidays,
          > I wonder if anyone in this group has experience with outboard
          > jet drives. I have talked to designers who say that it is hard to
          > make an inboard/jet drive work smoothly because alot of air
          > (bubbles) are trapped under the hull and consequently fed to the
          jet
          > pump with a poor result in propulsion. I wonder if outboard jets
          > would work better since they can be adjusted for depth independent
          > of the hull.
          > On the Upper Delaware River where I live I see Carolina skiffs
          > going though 6" deep water at 20-30 MPH with 100/+- HP engines on
          > their transoms. Imagine how nice this might work on some of the
          PCB
          > sharpie boats.
          >
          > Don
        • Don Tyson
          Dave B, How is reverse on your 19 Sled? Do you use reverse much while manuvering? dkb715 wrote: Don, I have a Yamaha 115 HP 4 stroke
          Message 4 of 8 , Jan 4, 2004
          • 0 Attachment
            Dave B, How is reverse on your 19' Sled? Do you use reverse much while manuvering?


            dkb715 <lburright@...> wrote:
            Don,

            I have a Yamaha 115 HP 4 stroke outboard with a jet that I have
            mounted on a 19' sled I finished about 2 1/2 years ago. The boat
            has a modified V hull. Some of the other replies were right in that
            you lose about 25 - 30% of your power with the jet. You don't want
            the water intake hanging down significantly below the back of the
            transom (mine is pretty much even with it). The whole idea behind
            the jet is to allow you to travel in shallow water. It would also
            produce a lot of drag.

            The jet is also a real pig at slow speeds. Maneuverability is a
            major challenge, especially when docking. The inboard jets seem to
            be much better because they have a bigger bucket.

            Dave B


            --- In bolger@yahoogroups.com, "tysond99" wrote:
            > Happy Hollidays,
            > I wonder if anyone in this group has experience with outboard
            > jet drives. I have talked to designers who say that it is hard to
            > make an inboard/jet drive work smoothly because alot of air
            > (bubbles) are trapped under the hull and consequently fed to the
            jet
            > pump with a poor result in propulsion. I wonder if outboard jets
            > would work better since they can be adjusted for depth independent
            > of the hull.
            > On the Upper Delaware River where I live I see Carolina skiffs
            > going though 6" deep water at 20-30 MPH with 100/+- HP engines on
            > their transoms. Imagine how nice this might work on some of the
            PCB
            > sharpie boats.
            >
            > Don


            Bolger rules!!!
            - no cursing, flaming, trolling, spamming, or flogging dead horses
            - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
            - Pls add your comments at the TOP, SIGN your posts, and snip away
            - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
            - Unsubscribe: bolger-unsubscribe@yahoogroups.com
            - Open discussion: bolger_coffee_lounge-subscribe@yahoogroups.com

            Yahoo! Groups Links

            To visit your group on the web, go to:
            http://groups.yahoo.com/group/bolger/

            To unsubscribe from this group, send an email to:
            bolger-unsubscribe@yahoogroups.com

            Your use of Yahoo! Groups is subject to:
            http://docs.yahoo.com/info/terms/



            [Non-text portions of this message have been removed]
          • doug6949
            Jet drives are not very efficient in terms of power conversion but they are quite common in whitewater boats. The folks down in NZ have them figured out. I
            Message 5 of 8 , Jan 4, 2004
            • 0 Attachment
              Jet drives are not very efficient in terms of power conversion but
              they are quite common in whitewater boats. The folks down in NZ have
              them figured out. I think the Kiwi brand is Shotover. Jet boats were
              also popular in Idaho for awhile. I do not recall whether they were
              sterndrive or full inboard though. My guess is full inboard because
              they routinely jump sandbars, rocks and logs with them.

              This type of propulsion is even less efficient in displacement hulls.
              If shallow water is your main concern you might consider a Thai
              longshaft. Go-Devil is a popular American rendition of this idea. They
              are incredibly easy to build.

              Doug
            • dkb715
              Don, Reverse is not very efficient. Again, I think it s because the bucket on outboards isn t very large. (The bucket is the piece that moves up over the
              Message 6 of 8 , Jan 4, 2004
              • 0 Attachment
                Don,

                Reverse is not very efficient. Again, I think it's because
                the "bucket" on outboards isn't very large. (The bucket is the
                piece that moves up over the jet to re-direct the water back to the
                sides.) I don't use reverse very much for this reason. If I need
                to hold myself in a current, I face into it. The other use is
                docking which isn't good.j

                I don't mean to sound too negative. I love the jet for running in
                the rivers. I can definitely go where others can't, and that's what
                it's for. For slow speed manuevering, it's not worth a hoot.

                Dave B


                --- In bolger@yahoogroups.com, Don Tyson <tysond99@y...> wrote:
                > Dave B, How is reverse on your 19' Sled? Do you use reverse much
                while manuvering?
                >
                >
                > dkb715 <lburright@c...> wrote:
                > Don,
                >
                > I have a Yamaha 115 HP 4 stroke outboard with a jet that I have
                > mounted on a 19' sled I finished about 2 1/2 years ago. The boat
                > has a modified V hull. Some of the other replies were right in
                that
                > you lose about 25 - 30% of your power with the jet. You don't want
                > the water intake hanging down significantly below the back of the
                > transom (mine is pretty much even with it). The whole idea behind
                > the jet is to allow you to travel in shallow water. It would also
                > produce a lot of drag.
                >
                > The jet is also a real pig at slow speeds. Maneuverability is a
                > major challenge, especially when docking. The inboard jets seem to
                > be much better because they have a bigger bucket.
                >
                > Dave B
                >
                >
                > --- In bolger@yahoogroups.com, "tysond99" wrote:
                > > Happy Hollidays,
                > > I wonder if anyone in this group has experience with outboard
                > > jet drives. I have talked to designers who say that it is hard
                to
                > > make an inboard/jet drive work smoothly because alot of air
                > > (bubbles) are trapped under the hull and consequently fed to the
                > jet
                > > pump with a poor result in propulsion. I wonder if outboard jets
                > > would work better since they can be adjusted for depth
                independent
                > > of the hull.
                > > On the Upper Delaware River where I live I see Carolina skiffs
                > > going though 6" deep water at 20-30 MPH with 100/+- HP engines
                on
                > > their transoms. Imagine how nice this might work on some of the
                > PCB
                > > sharpie boats.
                > >
                > > Don
                >
                >
                > Bolger rules!!!
                > - no cursing, flaming, trolling, spamming, or flogging dead horses
                > - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred'
                posts
                > - Pls add your comments at the TOP, SIGN your posts, and snip away
                > - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA,
                01930, Fax: (978) 282-1349
                > - Unsubscribe: bolger-unsubscribe@yahoogroups.com
                > - Open discussion: bolger_coffee_lounge-subscribe@yahoogroups.com
                >
                > Yahoo! Groups Links
                >
                > To visit your group on the web, go to:
                > http://groups.yahoo.com/group/bolger/
                >
                > To unsubscribe from this group, send an email to:
                > bolger-unsubscribe@yahoogroups.com
                >
                > Your use of Yahoo! Groups is subject to:
                > http://docs.yahoo.com/info/terms/
                >
                >
                >
                > [Non-text portions of this message have been removed]
              • Don Tyson
                Are go Devils ever installed to utilixe remoe controls or must one stand by and hoist or steer manually? they are pretty simple and therefore atractive to me.
                Message 7 of 8 , Jan 4, 2004
                • 0 Attachment
                  Are go Devils ever installed to utilixe remoe controls or must one stand by and hoist or steer manually? they are pretty simple and therefore atractive to me.

                  doug6949 <prototype@...> wrote:Jet drives are not very efficient in terms of power conversion but
                  they are quite common in whitewater boats. The folks down in NZ have
                  them figured out. I think the Kiwi brand is Shotover. Jet boats were
                  also popular in Idaho for awhile. I do not recall whether they were
                  sterndrive or full inboard though. My guess is full inboard because
                  they routinely jump sandbars, rocks and logs with them.

                  This type of propulsion is even less efficient in displacement hulls.
                  If shallow water is your main concern you might consider a Thai
                  longshaft. Go-Devil is a popular American rendition of this idea. They
                  are incredibly easy to build.

                  Doug


                  Bolger rules!!!
                  - no cursing, flaming, trolling, spamming, or flogging dead horses
                  - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
                  - Pls add your comments at the TOP, SIGN your posts, and snip away
                  - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
                  - Unsubscribe: bolger-unsubscribe@yahoogroups.com
                  - Open discussion: bolger_coffee_lounge-subscribe@yahoogroups.com

                  Yahoo! Groups Links

                  To visit your group on the web, go to:
                  http://groups.yahoo.com/group/bolger/

                  To unsubscribe from this group, send an email to:
                  bolger-unsubscribe@yahoogroups.com

                  Your use of Yahoo! Groups is subject to:
                  http://docs.yahoo.com/info/terms/




                  [Non-text portions of this message have been removed]
                • Don Tyson
                  Dave I have to confess that I don t know a hoot about motor boats, having been a sailor for many years. I assume reverse is often used at moderate speeds to
                  Message 8 of 8 , Jan 4, 2004
                  • 0 Attachment
                    Dave I have to confess that I don't know a hoot about motor boats, having been a sailor for many years. I assume reverse is often used at moderate speeds to slow or stop a motor boat. Reverse never worked on my sailboat on account of the boat being 8000lbs and the 8hp engine having only a 6" prop. When I hit reverse at 6 knts it took several hundred feet to stop the boat. I don't ever want that arrangement again.

                    dkb715 <lburright@...> wrote:Don,

                    Reverse is not very efficient. Again, I think it's because
                    the "bucket" on outboards isn't very large. (The bucket is the
                    piece that moves up over the jet to re-direct the water back to the
                    sides.) I don't use reverse very much for this reason. If I need
                    to hold myself in a current, I face into it. The other use is
                    docking which isn't good.j

                    I don't mean to sound too negative. I love the jet for running in
                    the rivers. I can definitely go where others can't, and that's what
                    it's for. For slow speed manuevering, it's not worth a hoot.

                    Dave B


                    --- In bolger@yahoogroups.com, Don Tyson wrote:
                    > Dave B, How is reverse on your 19' Sled? Do you use reverse much
                    while manuvering?
                    >
                    >
                    > dkb715 wrote:
                    > Don,
                    >
                    > I have a Yamaha 115 HP 4 stroke outboard with a jet that I have
                    > mounted on a 19' sled I finished about 2 1/2 years ago. The boat
                    > has a modified V hull. Some of the other replies were right in
                    that
                    > you lose about 25 - 30% of your power with the jet. You don't want
                    > the water intake hanging down significantly below the back of the
                    > transom (mine is pretty much even with it). The whole idea behind
                    > the jet is to allow you to travel in shallow water. It would also
                    > produce a lot of drag.
                    >
                    > The jet is also a real pig at slow speeds. Maneuverability is a
                    > major challenge, especially when docking. The inboard jets seem to
                    > be much better because they have a bigger bucket.
                    >
                    > Dave B
                    >
                    >
                    > --- In bolger@yahoogroups.com, "tysond99" wrote:
                    > > Happy Hollidays,
                    > > I wonder if anyone in this group has experience with outboard
                    > > jet drives. I have talked to designers who say that it is hard
                    to
                    > > make an inboard/jet drive work smoothly because alot of air
                    > > (bubbles) are trapped under the hull and consequently fed to the
                    > jet
                    > > pump with a poor result in propulsion. I wonder if outboard jets
                    > > would work better since they can be adjusted for depth
                    independent
                    > > of the hull.
                    > > On the Upper Delaware River where I live I see Carolina skiffs
                    > > going though 6" deep water at 20-30 MPH with 100/+- HP engines
                    on
                    > > their transoms. Imagine how nice this might work on some of the
                    > PCB
                    > > sharpie boats.
                    > >
                    > > Don
                    >
                    >
                    > Bolger rules!!!
                    > - no cursing, flaming, trolling, spamming, or flogging dead horses
                    > - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred'
                    posts
                    > - Pls add your comments at the TOP, SIGN your posts, and snip away
                    > - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA,
                    01930, Fax: (978) 282-1349
                    > - Unsubscribe: bolger-unsubscribe@yahoogroups.com
                    > - Open discussion: bolger_coffee_lounge-subscribe@yahoogroups.com
                    >
                    > Yahoo! Groups Links
                    >
                    > To visit your group on the web, go to:
                    > http://groups.yahoo.com/group/bolger/
                    >
                    > To unsubscribe from this group, send an email to:
                    > bolger-unsubscribe@yahoogroups.com
                    >
                    > Your use of Yahoo! Groups is subject to:
                    > http://docs.yahoo.com/info/terms/
                    >
                    >
                    >
                    > [Non-text portions of this message have been removed]


                    Bolger rules!!!
                    - no cursing, flaming, trolling, spamming, or flogging dead horses
                    - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
                    - Pls add your comments at the TOP, SIGN your posts, and snip away
                    - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
                    - Unsubscribe: bolger-unsubscribe@yahoogroups.com
                    - Open discussion: bolger_coffee_lounge-subscribe@yahoogroups.com

                    Yahoo! Groups Links

                    To visit your group on the web, go to:
                    http://groups.yahoo.com/group/bolger/

                    To unsubscribe from this group, send an email to:
                    bolger-unsubscribe@yahoogroups.com

                    Your use of Yahoo! Groups is subject to:
                    http://docs.yahoo.com/info/terms/




                    [Non-text portions of this message have been removed]
                  Your message has been successfully submitted and would be delivered to recipients shortly.