Re: [bolger] Re: engines
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
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
--- Inbolger@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
>
>
> --- Inbolger@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
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> - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
>
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>
>
> [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
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[Non-text portions of this message have been removed]
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
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To visit your group on the web, go to:
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[Non-text portions of this message have been removed]
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/
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[Non-text portions of this message have been removed]
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
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
--- Inbolger@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
>
>
> --- Inbolger@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]
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
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
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
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
--- Inbolger@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:
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[Non-text portions of this message have been removed]
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
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
--- Inbolger@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
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.
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.
--- Inbolger@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
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
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