cooling question???

[jollymon2]

While winterizing a newly purchased 1983 catalina 30 with a universal 5411 raw water cooled some serious confusion came about.

Only owned and used the boat for about 2 months before haul out. One of the first thing noticed was the lack of water spitting out of the exhaust through hull. I would estimate the amount of water at less that half the amount expelled by other diesel in board powered sail boats that I've been on. After some research I was convinced this was an impeller issue, which upon disassembly, no doubt needed changed, but did not change the amount of water exiting the exhaust. I should note that this engine has NEVER had a temperature issue, even before the impeller was changed. If anything, I was shocked by how long it would take for the temperature gauge to register any thing at all.

Which brings me to my question/concern. With the boat being on the cradle and running the engine to circulate antifreeze throughout the system, I wasn't surprised at the lack of antifreeze spitting out the exhaust port. More so I was shocked at the amount of antifreeze pouring out of the area where the prop shaft exits the hull. I would estimate that 90% of the fluid being circulated through the engine was exiting the boat in this area.

So now I'm fairly confident that antifreeze has been properly ran through the engine. But very confused about where the antifreeze is exiting. I need to understand this. No one at my marina seems to be able to offer good advice. Those nice enough to offer advice seem to know less than I do, which is not much.

Just to recap, this engine never even came close to getting " hot" and the bilge is dry.

Any advice would be much appreciated.

Thanks

 

[centerline]

While winterizing a newly purchased 1983 catalina 30 with a universal 5411 raw water cooled some serious confusion came about.

Only owned and used the boat for about 2 months before haul out. One of the first thing noticed was the lack of water spitting out of the exhaust through hull. I would estimate the amount of water at less that half the amount expelled by other diesel in board powered sail boats that I've been on. After some research I was convinced this was an impeller issue, which upon disassembly, no doubt needed changed, but did not change the amount of water exiting the exhaust. I should note that this engine has NEVER had a temperature issue, even before the impeller was changed. If anything, I was shocked by how long it would take for the temperature gauge to register any thing at all.

Which brings me to my question/concern. With the boat being on the cradle and running the engine to circulate antifreeze throughout the system, I wasn't surprised at the lack of antifreeze spitting out the exhaust port. More so I was shocked at the amount of antifreeze pouring out of the area where the prop shaft exits the hull. I would estimate that 90% of the fluid being circulated through the engine was exiting the boat in this area.

So now I'm fairly confident that antifreeze has been properly ran through the engine. But very confused about where the antifreeze is exiting. I need to understand this. No one at my marina seems to be able to offer good advice. Those nice enough to offer advice seem to know less than I do, which is not much.

Just to recap, this engine never even came close to getting " hot" and the bilge is dry.

Any advice would be much appreciated.

Thanks

It sounds like its time for you to become familier with the engine compartment.... you gonna have to get in thereand see if there is some sort of hose going to the bearing/sealing area that could be carrying water to the area to insure cooling...

Ive never heard of a cooling system such as this, but what else could cause the engine cooling water to exit around the prop shaft, and not allow leakage into the bilge?!!!!

 

[Jack - La Paz Mx]

We have had our '82 Cat since 1995. It has the 5411 engine. The way the raw water is circulated it does not spit out water in great quantities like other diesels. In fact, the 5411 will spurt some steam out the exhaust which has caused other sailors to warn me of my engine overheating. It never does, runs constantly at 135 degrees. We are in warm water and still no overheating. The limited water in the exhaust is a fact of the 5411 engine. Now, water coming out the prop shaft exit and a dry bilge makes no sense. There is no connection. Spend some time looking at the stuffing box, shaft exit out of the hull, the strut under the hull. No passage for cooling water. Water from the engine intake thruhull goes thru the engine, circulates around again regulated by the thermostat, and is injected into the exhaust system and muffler. Look at this link and especially p. 35. The mixing Tee is why you don't see much water in the exhaust. As long as the temp does not go above 150 degrees, you are fine.

http://downeasteryachts.com/wp-cont...Model-30-operation-and-maintenance-manual.pdf

 

[jrowan]

Jack's explanation of the 5411 cooling system is accurate.
I also found the lack of cooling water exiting the stern disturbing at first.
In the summer months, when you don't have to worry about the engine
warming up via raw water coolant recirculation, you can leave the valve shut that sends water into the thermostatically controlled loop. If your engine is not plumbed with this valve, then you can also remove the thermostat, so that raw water will be pumped through then engine only once, then out immediately through to the raw water muffler, like most conventional diesel raw water cooling set ups. It will just take a little longer for the engine to warm up. But our 5411 always run cool anyway, which may help to explain their incredible longevity & durability.
But as far as coolant leaking from the prop shaft, this could only be explained if there was a leak in the water muffler, & also at the prop shaft seal of the stuffing box. If it leaked that badly, the bilge would be full of water with your bilge pump running non stop.
Either way it sounds like you should have a marine diesel mechanic look the engine over to make sure you don't have a major leak in your cooling system. But don't despair. Our much maligned lil' 5411 engines are about the toughest engine ever built, besides the venerable Atomic 4.

 

[Capt jgw]

The PO (Previous Owner, often otherwise refered to as "Moron", even by people who've bought boats from me) may have installed a dripless shaft seal which is water injected. Look behind the engine for a small hose running into the fitting on the propeller shaft. The other end of the hose will be tee'd into one of the cooling hoses. If you have one of these it explains the water coming out of the shaft log, and it's a good upgrade to have. No more seawater dripping into the bilge from the shaft. I have one on my boat but I didn't connect the injection line as on the model I bought the injection is unnecessary under 10 knots.