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