seagweed and cooling system
 

On 7/10/2011 3:24 PM, Wayne B wrote:
On Sun, 10 Jul 2011 08:01:28 -0400, wrote:

On 7/9/2011 11:37 PM, Wayne B wrote:
On Sat, 09 Jul 2011 17:30:26 -0400, wrote:

Bob should install water temp and oil pressure gauges. Also an audible
idiot alarm and maybe an idiot light. He could use the same audible
idiot alarm for both water and oil.

It has been proven that water temp gauges do a great job of telling
you when it is already too late. No joke, usually the damage is done
unless you catch it very quickly.

There are two different sensors that can alert you in time: The first
is a raw water pressure sensor/alarm installed downstream of the raw
water pump. The second is a temperature sensor/alarm at the exhaust
elbow. Either or both of these give you enough warning time to shut
down before damage occurs. Many modern engines have both.


A lot of folks don't glance at their instruments often enough. In bobs
case, a gauge or horn probably would have alerted him to problems. Also
the steam coming out the exhaust usually foretells engine damage.
Misfiring or backfiring could also be a warning sign. Or if the engine
slows down without any other signs you might be experiencing engine
seizure. I'm not trying to scare bob, but he needs to pay attention better.

My point was that no one can watch their gauges every second, and
warning alarms usually go off too late to save damage. Most engines
have some sort of audible alarm for high cylinder head temperature and
low oil pressure. The problem is that by the time temperature hits
the alarm level, you've already cracked the cylinder head or blown the
gasket.

By moving the alarms farther upstream in the cooling system you get
more advanced warning and can shut down without permanent damage being
done. Most of the newer Mercruiser engines with computer controls are
alarmed on both raw water pressure and exhaust elbow temperature. My
7 year old Kohler generator is also setup the same way only with auto
shutdown instead of an alarm. It is relatively easy and inexpensive
to retro fit an older engine with an exhaust elbow alarm and it will
go off almost instantly if cooling water is disrupted for some
reason.


I'll defer to the engineers who designed the alarm systems. I think we
both agree that an audible alarm is the best way to get the helmsman's
attention. Then he can look at gauges to determine what's wrong.

seagweed and cooling system
 

In article , says...

On 7/10/2011 3:24 PM, Wayne B wrote:
On Sun, 10 Jul 2011 08:01:28 -0400, wrote:

On 7/9/2011 11:37 PM, Wayne B wrote:
On Sat, 09 Jul 2011 17:30:26 -0400, wrote:

Bob should install water temp and oil pressure gauges. Also an audible
idiot alarm and maybe an idiot light. He could use the same audible
idiot alarm for both water and oil.

It has been proven that water temp gauges do a great job of telling
you when it is already too late. No joke, usually the damage is done
unless you catch it very quickly.

There are two different sensors that can alert you in time: The first
is a raw water pressure sensor/alarm installed downstream of the raw
water pump. The second is a temperature sensor/alarm at the exhaust
elbow. Either or both of these give you enough warning time to shut
down before damage occurs. Many modern engines have both.


A lot of folks don't glance at their instruments often enough. In bobs
case, a gauge or horn probably would have alerted him to problems. Also
the steam coming out the exhaust usually foretells engine damage.
Misfiring or backfiring could also be a warning sign. Or if the engine
slows down without any other signs you might be experiencing engine
seizure. I'm not trying to scare bob, but he needs to pay attention better.

My point was that no one can watch their gauges every second, and
warning alarms usually go off too late to save damage. Most engines
have some sort of audible alarm for high cylinder head temperature and
low oil pressure. The problem is that by the time temperature hits
the alarm level, you've already cracked the cylinder head or blown the
gasket.

By moving the alarms farther upstream in the cooling system you get
more advanced warning and can shut down without permanent damage being
done. Most of the newer Mercruiser engines with computer controls are
alarmed on both raw water pressure and exhaust elbow temperature. My
7 year old Kohler generator is also setup the same way only with auto
shutdown instead of an alarm. It is relatively easy and inexpensive
to retro fit an older engine with an exhaust elbow alarm and it will
go off almost instantly if cooling water is disrupted for some
reason.


I'll defer to the engineers who designed the alarm systems. I think we
both agree that an audible alarm is the best way to get the helmsman's
attention. Then he can look at gauges to determine what's wrong.

They make nice LED gages for race cars that flash one color (like
Yellow) as you get near the limits you set, and then Red when you go
over the threshold...

--
Team Rowdy Mouse, Banned from the Mall for life!

seagweed and cooling system
 

On Sat, 09 Jul 2011 23:37:12 -0400, Wayne B
wrote:

The second is a temperature sensor/alarm at the exhaust
elbow. Either or both of these give you enough warning time to shut
down before damage occurs. Many modern engines have both.

I have a glycol cooled engine, and and elbow sensor would warn long
before the coolant began to boil at 250 plus.

seagweed and cooling system
 

"wf3h" wrote in message ...

On Sat, 9 Jul 2011 12:44:35 -0700 (PDT), Tim
wrote:

On Jul 9, 11:59 am, wf3h wrote:
my 26' tolly has a freshwater cooling system. i put new water lines on
last year so everything is in great shape.

took it out last weekend in the fairway to practice docking. engine
kept stalling at slow speed (600 rpm). got it back into the slip and
found the bilge pump was running. opened the bilge and found the
cooling water line from the throughull to the cooling water pump had
completely collapsed even though it was wire reinforced. the end of
the line had ripped away from the throughhull and water was streaming
in.

i shut the seacock and let the boat pump out put a new water line on,
started the engine and it ran like a charm with no overheating.

looking at the collapsed line...i remembered that the previous week
the marina had filled with seaweed. some of this probably got stuck on
the strainer and blocked the inlet.er

before i put the new water line on, i backflushed the strainer with
water and got good flow. but will keep an eye out for seaweed in the
future.

Bob, I dont know how course the strain3er is but I'[d think you'd see
evidence of the sea weed stuck in the hose or the screen. Then again,
i wouldn't think you'd gotten a bad hose but.... still a bummer!
l
saw bits and pieces of seaweed in the bilge..but backflushedl the
strain so hope i got rid of it all...engiine seems to run OK so will
replace impeller


REPLY:
You need to pull the end cap on the heat exchanger. That will be where
little pieces of seaweed and Nemo will collect, cutting down on water flow.
Is one weak point on Fresh water cooled engines. Little tubes, lots of
little tubes that can plug.

seagweed and cooling system
 

On Mon, 11 Jul 2011 13:36:34 -0700, "Califbill"
wrote:

"wf3h" wrote in message ...

On Sat, 9 Jul 2011 12:44:35 -0700 (PDT), Tim
wrote:

Bob, I dont know how course the strain3er is but I'[d think you'd see
evidence of the sea weed stuck in the hose or the screen. Then again,
i wouldn't think you'd gotten a bad hose but.... still a bummer!
l
saw bits and pieces of seaweed in the bilge..but backflushedl the
strain so hope i got rid of it all...engiine seems to run OK so will
replace impeller


REPLY:
You need to pull the end cap on the heat exchanger. That will be where
little pieces of seaweed and Nemo will collect, cutting down on water flow.
Is one weak point on Fresh water cooled engines. Little tubes, lots of
little tubes that can plug.

good points...will check

seagweed and cooling system
 

wf3h wrote:
On Sat, 09 Jul 2011 23:02:18 -0400, L wrote:


wf3h wrote:

my 26' tolly has a freshwater cooling system. i put new water lines on
last year so everything is in great shape.

took it out last weekend in the fairway to practice docking. engine
kept stalling at slow speed (600 rpm). got it back into the slip and
found the bilge pump was running. opened the bilge and found the
cooling water line from the throughull to the cooling water pump had
completely collapsed even though it was wire reinforced. the end of
the line had ripped away from the throughhull and water was streaming
in.

i shut the seacock and let the boat pump out put a new water line on,
started the engine and it ran like a charm with no overheating.

looking at the collapsed line...i remembered that the previous week
the marina had filled with seaweed. some of this probably got stuck on
the strainer and blocked the inlet.

before i put the new water line on, i backflushed the strainer with
water and got good flow. but will keep an eye out for seaweed in the
future.


If your intent was to prove you can't capitalize properly, you hit a
home run. Other than that, blind man, what was the purpose of your post?

this is a boating newsgroup, right?

Thanks to your buddies, not really. Your lazy writing "style" makes you
look dumber than you actually are.

It's possible that seaweed plugged the strainer on the outside of the
hull (usually the through hull intake has either an integral strainer
or a domed strainer cover.