(dead engine update) was dead engines, kayaks, and powerboaters
 

"Capt. JG" wrote in message
...
Just got an email from the maintenance crew who looked at the engine
situation.... interestingly, we did check the coolant level, which was
fine. So, whomever said the impeller, was dead on...

(edited slightly) The engine lost coolant (which was the consequence of an
overheat situation earlier in the month) and was running hot (in the
185-190+ deg range), which was enough to activate the over-heat alarm and
to still run "as if the alarm was a false negative." The raw-water cooling
was working, but the blades of the impeller had been deformed causing the
quantity of cooling water running through the heat-exchanger to be
insufficient to cool the engine to within it's operating temperature
range, thus causing the alarm.


We will routinely replace raw water impellers in all overheating situation
in the future, as well as positively check the flow of raw water cooling
throughout the complete system: through-hull to mixing elbow.

--
"j" ganz @@
www.sailnow.com

Been there, seen that.
The problem is that as the impellers age the lobes get stiff and do not
spring back into position quickly enough after passing the hump that
squeezes the water along its way.
It is during this 'spring-back' period that the impeller lobe is supposed to
seal itself against the casing and draw water into the gap between the
impellers. When spring-back is too slow the pump throughput gradually
reduces due to poor sealing and/or insufficient water drawn into the gaps
between lobes..

(dead engine update) was dead engines, kayaks, and powerboaters
 

"Wayne.B" wrote in message
...
On Sat, 10 Nov 2007 11:23:06 -0800, "Capt. JG"
wrote:

We will routinely replace raw water impellers in all overheating situation
in the future, as well as positively check the flow of raw water cooling
throughout the complete system: through-hull to mixing elbow.

Based on my experience with the small Yanmar in my genset, I'd
recommend being even more proactive than that. The impellers seem to
self destruct after about 200 hours so it's better to replace them on
a periodic basis before that happens. One nice feature on my genset
is a temperature sensor on the exhaust elbow. It trips as soon as
cooling water flow starts to slow down. Supposedly you can buy the
sensors at Home Depot for minimal $$$s and attach them with hose
clamps.


Fortunately, I'm not the one responsible for the engines or boats for that
matter. I will take the advice under advisement for mine, however.

--
"j" ganz @@
www.sailnow.com

(dead engine update) was dead engines, kayaks, and powerboaters
 

"Dave" wrote in message
...
On Sat, 10 Nov 2007 23:49:28 -0500, Wayne.B
said:

Based on my experience with the small Yanmar in my genset, I'd
recommend being even more proactive than that. The impellers seem to
self destruct after about 200 hours so it's better to replace them on
a periodic basis before that happens.

I change mine annually as part of spring maintenance,, and keep the old
one
as a spare.

Overkill! I bet you change the oil and filter in your car every 200 miles.
Changing your impeller every spring is about that premature.

Wilbur Hubbard

dead engines, kayaks, and powerboaters
 

On Tue, 6 Nov 2007 12:08:34 -0800, "Lew Hodgett"
wrote:

Am convinced that for the most part, to qualify to receive the keys to
a power vessel, you must certify you only have 2 brain cells, of which
at least one must be dead.

While you are at it, get rid of all the engines, including those in
sailboats. Real sailors don't need them. Joshua Slocum didn't an
engine or any electrics. I wonder what he did with all the time he
didn't spend maintaining that stuff.

Casady

dead engines, kayaks, and powerboaters
 

On Wed, 07 Nov 2007 20:53:32 -0500, Wayne.B
wrote:

On Wed, 07 Nov 2007 14:38:31 -0500, "mr.b" wrote:

that's obvious...but not to the point...the discussion was about the
ignorant and arrogant who pilot their stinktubs with what could be
described as a less than cooperative spirit...like the moron described by
the OP.

A lot of it is a perception issue. People in larger, faster boats are
percieved as being arrogant, particularly if they are well dressed or
in the company of good looking women. If they inconvenience or
discomfit us, they are percieved as being ignorant. Take that same
person and put him down on your level in a sailboat and all of a
sudden he is an educated, well spoken, all around nice guy.

Perceptions.

Funny, but every sailor I have known has owned at least one powerboat.
While owning a good sized cruising sailboat may be a full time job,
some people have a whole fleet of under twenty foot boats. At one time
my family had four sailboats two powerboats and a canoe. And there has
been surprisingly little rudeness on the water. Maybe it is the fact
that on a 6500 acre lake there is no place to hide. All the resorts
are gone, private homes have taken over, and you mostly deal with the
same boats and the same people year after year. The lake does have a
cop. There are public boat ramps and a campground, and it is people
from elsewhere that cause the rare problems.

Casady

dead engines, kayaks, and powerboaters
 

On Wed, 07 Nov 2007 14:31:25 -0500, Wayne.B
wrote:

Nonsense. Have you ever seen the wake from a freighter or fast tug
boat? If so you'll never complain about sportfish or motoryachts.

I believe that aircraft carriers have the biggest wakes. What with 300
000 HP. Freighters, and tankers only come in HP under 100 000, all
single screw diesels, although many are bigger than a flattop. A
submarine at full power on the surface will also move lots of water.

Casady

dead engines, kayaks, and powerboaters
 

On Tue, 06 Nov 2007 19:24:43 -0200, Timothy Tannebaum
wrote:

No dayshapes displayed for limited maneuverability!

Ball-Diamond-Ball!!!!!

Some of the merchant sailors call the two balls 'Panama running
lights'

Casady

dead engines, kayaks, and powerboaters
 

On Thu, 08 Nov 2007 10:55:33 -0300, Axel Merckx
wrote:

Ganz had the right of way because he was under sail in a narrow
channel. He lost the right of way when he turned on the engine. Why
can't any of the people here read the ColRegs or Inland rules and
resolve the issue of right of way? It's no wonder the coastal areas
are chock full of idiots.

As near as I can figure, according to the Colregs, there is no such
thing as blameless in a collision. A drunk ran down a guy, here in
Iowa, from behind. The victim wasn't keeping a lookout. Happened at
night. Boat went right over the top of the victims boat, and the drive
unit hit the helmsman and killed him. The drunk went to prison.
Then there was the time the local cops hit an anchored boat, at night,
close to shore, at high speed. They killed a guy. Cops tried to claim
that the anchored boat wasn't showing the proper lights. That BS
didn't sell.

Take the psychobabble and put it where the sun doesn't shine buddy.
This is a sailing forum, not some wet nurse looney bin.

Amen.

Casady

dead engines, kayaks, and powerboaters
 

On Wed, 07 Nov 2007 01:50:41 GMT, Jere Lull wrote:

We've found that even with the fresh water closed off, we have about 5
minutes' run-time at cruise power (about 2200 rpm) before the high-temp
alarm sounds -- quite a bit further than 200 meters. We used that
reserve once about a decade ago, so I know it exists.

I am not sure I would rely on the light to protect the engine. I know
that it is supposed to...

What do you mean by fresh water. My [22 ft sterndrive] is cooled by
glycol and has a heat exchanger. If I am floating in salt water, there
is no fresh water involved anywhere.

I have heard the heat exchanger/glycol arrangement refered to as fresh
water cooling. There is seldom [never?] a shutoff in the coolant
lines, although there is generally a seacock in the raw water line.
When was the last time you saw a shutoff in a car cooling system?
One thing is certain, unless the pump is managing to circulate coolant
through the engine, it won't last anything like five minutes. The
difference between driving with a broken fan belt, and driving with no
coolant. That will warp the head[s] almost immediately. You got away
with it once, so appearantly the light gives sufficient warning. I
like a gauge. That shows up a problem sooner than a light. My car has
both gauge and light for the oil pressure.

Casady

dead engines, kayaks, and powerboaters
 

"Richard Casady" wrote:

I believe that aircraft carriers have the biggest wakes. What with
300
000 HP. Freighters, and tankers only come in HP under 100 000, all
single screw diesels, although many are bigger than a flattop. A
submarine at full power on the surface will also move lots of water.

Can't comment on any of the above; however, the bow wave generated by
a 1,000 ft ore boat, loaded out at 60,000 tons of iron ore, can be
felt for miles.

One of the reasons these boats travel in the middle of the lake.

Lew