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627Re: Small air cooled inboard motors

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  • dmede808
    Apr 6, 2005
      No problem Mike. I appreciate the help. I do know about the thrust bearing issue. There
      is a load spec for the PTO bearing on the HATZ but I dont have any idea what the prop and
      shaft thrust load will be, or how to calculate it.

      HATZ has several gearbox options for those motors and I may use one for gear reduction
      and reverse gearing if possible. Hopefully that gearbox will be able to take the thrust load
      but if not I'll have to rig an inline thrust bearing. Mcmaster Carr has pillow-block bearings
      that may do the job.

      http://www.mcmaster.com/ctlg/DisplCtlgPage.asp?
      ReqTyp=CATALOG&CtlgPgNbr=1026&CtlgEdition=&RelatedCtlgPgs=1026,1027,1028,102
      9,1030,1031,1032,957,967,969,972,973,1010&sesnextrep=432744623004951&ScreenW
      idth=1600&McMMainWidth=1003


      --- In AtkinBoats@yahoogroups.com, "Mike Dolph" <jdolph@s...> wrote:
      >
      > Those are really interesting engines. I'm sorry to keep adding
      > problems with no real ability t help but there is one more necessary
      > component for a marine engine. You need a thrust bearing. This is
      > the bearing that absorbs the push of the propeller that's
      > transimitted up the shaft and transfers it to the hull usually via
      > the engine body and engine mounts. The alternative is to have the
      > shaft trying to spear through the engine.
      >
      > The marine engines have this designed into the reduction gear and the
      > forces are taken into account if they will be transmitted via the
      > engine block. This might be why we have "reduction/reverser" gears
      > vs "transmissions" in other vehicles. It's a fundamentally different
      > useage of the power. The United Nations FAO has a design for
      > something like this they used in India and I suspect Robb White did
      > something similar in his Rescue Minor. As I recall it makes use of
      > an automotive constant velocity joint fixed to a plate that's fixed
      > to the hull to allow the shaft to be raised out of the water. The
      > thrust bearing may have been "homebuilt".
      >
      >
      > John Dolph
      >
      > --- In AtkinBoats@yahoogroups.com, "dmede808" <dmede808@y...> wrote:
      > >
      > > Atkin specified a 10" prop with 6" pitch for the Victor Slocum.
      > >
      > > As you mentioned, RPMs are one of my big concerns. The small
      > diesel I found delivers
      > > 7.6hp at max 3600rpms and idles at 800rpms. Highest torque is
      > 13.5lbs.ft at 2000rpms.
      > > It delivers roughly 5hp at max torque 2000rpm. Probably higher RPM
      > range than the
      > > Palmer. The Palmer was rated at 6hp at 2500rpms.
      > >
      > > You can find PDF spec sheets of the motor I'm looking at here:
      > > http://www.hatz-diesel.de/englisch/produkt/1b20_e.htm
      > >
      > >
      > >
      > > --- In AtkinBoats@yahoogroups.com, "Mike Dolph" <jdolph@s...> wrote:
      > > >
      > > > I don't know of any air cooled engines being made today that are
      > > > equivalent to motors like the Baby Husky Palmer. Those engines
      > had a
      > > > long stroke to cylinder diameter ratio that let them deliver more
      > > > torque at lower rpm's. You would need a reduction gear and
      > probably
      > > > need to buy a motor rated at a higher horsepower than Atkin
      > specified
      > > > and run it at near it's best torque instead of at it's highest
      > speed
      > > > in order to deliver the same power to Atkins specified
      > propeller. I
      > > > Have been looking at some Brazilian Yanmar diesels (water cooled)
      > at
      > > >
      > http://www.yanmar.com.br/site/ing2/produtos/nacional/bm/especificacoes
      > .
      > > > doc
      > > >
      > > > These will deliver the torque to turn your specified propeller
      > but I
      > > > imagine you will end up changing that propeller to one that fits
      > the
      > > > motor you finally settle on.
      > > >
      > > > Does anyone know all these facts for the Baby Husky and the prop
      > > > speced for the Victor Slocum?
      > > >
      > > > John Dolph
      > > >
      > > > --- In AtkinBoats@yahoogroups.com, "dmede808" <dmede808@y...>
      > wrote:
      > > > >
      > > > >
      > > > > I am considering building the Victor Slocum, a 15' modified
      > Jersey
      > > > > skiff. The plans call for
      > > > > a small (6hp) air cooled gas inboard. I'm considering a small
      > air
      > > > > cooled diesel from HATZ
      > > > > instead but the hookup should be about the same.
      > > > >
      > > > > Anybody have any good reasources on how to install a small
      > inboard in
      > > > > an open boat like
      > > > > the Victor Slocum?
      > > > >
      > > > > Anybody know of someone who has built the Victor Slocum?
      > > > >
      > > > > Thanks,
      > > > > David
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