Realistic cruising under sail
 

"Larry" wrote in message
...
nom=de=plume wrote:
wrote in message
...

Even the best sailboat cannot sail much closer than 45 degrees to the
wind so this means at least 1/4 of the time you cannot sail directly
toward your destination (2*45 =90 which is 1/4 of 360). On a loaded
cruising boat, you will be lucky to get to within 55 degrees of the
wind so this eliminates 110 out of 360 degrees or 30%.
Where I live, NO wind at least 1/2 the time leaving only 35% of the
time you can sail toward your destination. About half the time while
trying to cruise, you get short of time so you end up motoring
directly toward your destination getting you down to 17.5% of the time
you can sail directly toward your destination. Around here, roughly
30% of the time the widn is blowing, it is a thunderstorm or tropical
storm getting you down to somewhere between 10 -13% of the time you
can sail toward your destination. This is why cruising sailboats need
adequate engines.


Interesting numbers. Of course, out here the wind is pretty high I think.
By
adequate... what do you mean? It needs to power the boat in most
conditions,
but if you're offshore and there's wind, you're likely sailing right? I
can
see needing something adequate in the bay or on the coast. The link I
found
said the boat had a 50hp, which seems pretty good for a 42' boat. Perhaps
fuel capacity is also an important issue...


Perhaps?


Well, again, if you're sailing and mostly relying on the wind, then the only
time you need the engine is in/out of a harbor or charging batteries (and
perhaps a couple of other uses like refridgeration). Seems to me if you're
conservative about how you use the engine, then it might not be such a big
deal.

--
Nom=de=Plume

Realistic cruising under sail
 

On Apr 21, 9:17*pm, Wayne.B wrote:
On Wed, 21 Apr 2010 18:09:16 -0700 (PDT), Tim
wrote:

There's a lot of sail boats that have 125 hp on up. The Ford Lehman
diesels are or at least were a popular marine engine for large sailers
as well as trawlers.

I know this is a 72 ft'r but it has twin Leymans at 120 hp each.

It turns out that the horsepower required for a boat to reach so
called hull speed is mostly a function of weight, and it is a
surprisingly small number for boats less than 100 tons or so.
Then you have to add in a fudge factor however for adverse conditions,
plus parasitic losses for things like alternators, refrigeration
compressors, hydraulic pumps, etc. * There are also losses in the
transmission and cutlass bearings. * A 70,000 pound trawler in theory
needs less than 90 hp to reach hull speed *but to have reasonable
margins of safety you need 3 or 4 times that much.

That's kid of what i was thinking Wayne. especially for the 'adverse
conditions' . in a bad storm I'd want to make it to a port or at least
to a harbor as fast as I could. But like I said, I'm not a blow
boater, but it would be nice to have all the punch you could get when
it's called upon.

Realistic cruising under sail
 

On Apr 22, 10:00*am, Tim wrote:
On Apr 21, 9:17*pm, Wayne.B wrote:



On Wed, 21 Apr 2010 18:09:16 -0700 (PDT), Tim
wrote:

There's a lot of sail boats that have 125 hp on up. The Ford Lehman
diesels are or at least were a popular marine engine for large sailers
as well as trawlers.

I know this is a 72 ft'r but it has twin Leymans at 120 hp each.

It turns out that the horsepower required for a boat to reach so
called hull speed is mostly a function of weight, and it is a
surprisingly small number for boats less than 100 tons or so.
Then you have to add in a fudge factor however for adverse conditions,
plus parasitic losses for things like alternators, refrigeration
compressors, hydraulic pumps, etc. * There are also losses in the
transmission and cutlass bearings. * A 70,000 pound trawler in theory
needs less than 90 hp to reach hull speed *but to have reasonable
margins of safety you need 3 or 4 times that much.

That's kid of what i was thinking Wayne. especially for the 'adverse
conditions' . in a bad storm I'd want to make it to a port or at least
to a harbor as fast as I could. But like I said, I'm not a blow
boater, but it would be nice to have all the punch you could get when
it's called upon.

I'd almost like to have an Atomic 4 engine, small, reliable and enough
power. If one is careful a gasoline engine can be very safe.

Realistic cruising under sail
 

On 4/22/10 10:35 AM, Frogwatch wrote:
On Apr 22, 10:00 am, wrote:
On Apr 21, 9:17 pm, wrote:



On Wed, 21 Apr 2010 18:09:16 -0700 (PDT),
wrote:

There's a lot of sail boats that have 125 hp on up. The Ford Lehman
diesels are or at least were a popular marine engine for large sailers
as well as trawlers.

I know this is a 72 ft'r but it has twin Leymans at 120 hp each.

It turns out that the horsepower required for a boat to reach so
called hull speed is mostly a function of weight, and it is a
surprisingly small number for boats less than 100 tons or so.
Then you have to add in a fudge factor however for adverse conditions,
plus parasitic losses for things like alternators, refrigeration
compressors, hydraulic pumps, etc. There are also losses in the
transmission and cutlass bearings. A 70,000 pound trawler in theory
needs less than 90 hp to reach hull speed but to have reasonable
margins of safety you need 3 or 4 times that much.

That's kid of what i was thinking Wayne. especially for the 'adverse
conditions' . in a bad storm I'd want to make it to a port or at least
to a harbor as fast as I could. But like I said, I'm not a blow
boater, but it would be nice to have all the punch you could get when
it's called upon.

I'd almost like to have an Atomic 4 engine, small, reliable and enough
power. If one is careful a gasoline engine can be very safe.

In someone else's boat, maybe. Not in yours.


--
The Tea Party's teabaggers are just the Republican base by another name.

Realistic cruising under sail
 

On Thu, 22 Apr 2010 07:35:04 -0700 (PDT), Frogwatch
wrote:

I'd almost like to have an Atomic 4 engine, small, reliable and enough
power. If one is careful a gasoline engine can be very safe.

Smooth, quiet, powerful, reliable and easy to work on. What's not to
like? We used to use ours a lot when cruising, typically motor
sailing in light air with the engine a little above idle. It would
run for a day like that on very little fuel and so quiet you hardly
knew it was on.

Realistic cruising under sail
 

On Apr 22, 5:24*pm, Wayne.B wrote:
On Thu, 22 Apr 2010 07:35:04 -0700 (PDT), Frogwatch

wrote:
I'd almost like to have an Atomic 4 engine, small, reliable and enough
power. *If one is careful a gasoline engine can be very safe.

Smooth, quiet, powerful, reliable and easy to work on. * What's not to
like? *We used to use ours a lot when cruising, typically motor
sailing in light air with the engine a little above idle. * It would
run for a day like that on very little fuel and so quiet you hardly
knew it was on.

I did som reading on the atomic-4 and it was a success from about 1947
to about 1984 when production ceased. I know they didn't change very
much but what was it's demise? Couldn't meet EPA? or just an out dated
flathead? Or a combination of a bunch of things?

Realistic cruising under sail
 

"Tim" wrote in message
...
On Apr 22, 5:24 pm, Wayne.B wrote:
On Thu, 22 Apr 2010 07:35:04 -0700 (PDT), Frogwatch

wrote:
I'd almost like to have an Atomic 4 engine, small, reliable and enough
power. If one is careful a gasoline engine can be very safe.

Smooth, quiet, powerful, reliable and easy to work on. What's not to
like? We used to use ours a lot when cruising, typically motor
sailing in light air with the engine a little above idle. It would
run for a day like that on very little fuel and so quiet you hardly
knew it was on.

I did som reading on the atomic-4 and it was a success from about 1947
to about 1984 when production ceased. I know they didn't change very
much but what was it's demise? Couldn't meet EPA? or just an out dated
flathead? Or a combination of a bunch of things?


Maybe it was the name. :)

--
Nom=de=Plume

Realistic cruising under sail
 

On Thu, 22 Apr 2010 15:30:53 -0700 (PDT), Tim
wrote:

I did som reading on the atomic-4 and it was a success from about 1947
to about 1984 when production ceased. I know they didn't change very
much but what was it's demise? Couldn't meet EPA? or just an out dated
flathead? Or a combination of a bunch of things?

I think it was a combination of things. Up until the late 70s, early
80s there were not a lot of choices for small marine engines. Volvo
made some small diesels but they were pricey, and to a certain extent,
a bit quirky. Then about that time Yanmars began coming into the US
in great numbers from Japan and at reasonable prices. Buyers and
builders began to percieve diesels as a better value and safer choice.
The rest is history.

One nice thing about the Volvos is that they were relatively easy to
crank start by hand thanks to large fly wheels and a compression
release lever. The trick was to open the compression release, get
the fly wheel spinning at a good clip with the crank, and then close
the release lever. The fly wheel had enough momentum to kick it over
a few times and get the engine started.

Realistic cruising under sail
 

On Apr 22, 8:51*pm, Wayne.B wrote:
On Thu, 22 Apr 2010 15:30:53 -0700 (PDT), Tim
wrote:

I did som reading on the atomic-4 and it was a success from about 1947
to about 1984 when production ceased. I know they didn't change very
much but what was it's demise? Couldn't meet EPA? or just an out dated
flathead? *Or a combination of a bunch of things?

I think it was a combination of things. *Up until the late 70s, early
80s there were not a lot of choices for small marine engines. *Volvo
made some small diesels but they were pricey, and to a certain extent,
a bit quirky. *Then about that time Yanmars began coming into the US
in great numbers from Japan and at reasonable prices. * Buyers and
builders began to percieve diesels as a better value and safer choice.
The rest is history.

One nice thing about the Volvos is that they were relatively easy to
crank start by hand thanks to large fly wheels and a compression
release lever. * The trick was to open the compression release, get
the fly wheel spinning at a good clip with the crank, and then close
the release lever. * The fly wheel had enough momentum to kick it over
a few times and get the engine started. *

I've never been able to hand crank my diesel, either the 6.5 hp nor
the 13 hp even by releasing the compression. On cold mornings, even
with new batteries, I have to release the compression to get the
engine turning to lube it before it will start. These little Yanmar
diesels are really amazingly simple and reliable. The biggest problem
is they use so little fuel that the fuel grows algae that clogs
filters and injectors.
Just for fun, I'd like to get an old Atomic 4 and re-build it.
There are a lot of used small diesels are available these days from
hurricane wrecked sailboats whereas for years they were rare to
find.
When I replaced the engine, the boat was on stands in my backyard
with the mast down and no easily available trees to hoist the engines,
it was like moving statues on Easter Island to get that engine out and
down and then the heavier new one up and in place. Once in the
compartment, it dropped right in place and lined up nicely.

Realistic cruising under sail
 

On Thu, 22 Apr 2010 21:04:25 -0700 (PDT), Frogwatch
wrote:

I've never been able to hand crank my diesel, either the 6.5 hp nor
the 13 hp even by releasing the compression.

Is it a Yanmar? If so they have much smaller/lighter fly wheels than
the old Volvo engines, and don't have enough angular momentum to carry
the piston through a compression stroke after you close the valve.