Keel Cooled and Dry Exhaust

[Xsbank]

Highjack alert!

I have to say that you have the absolutely grooviest, coolest, most awesome boat on here. Its like mine except yours is beautiful. If you would like to post some more photos on here, I would love to see them!

 

[Lou_tribal]

Highjack alert!

I have to say that you have the absolutely grooviest, coolest, most awesome boat on here. Its like mine except yours is beautiful. If you would like to post some more photos on here, I would love to see them!

You say so cause you did not see mine yet lol [emoji1]

L

 

[Delfin]

Highjack alert!

I have to say that you have the absolutely grooviest, coolest, most awesome boat on here. Its like mine except yours is beautiful. If you would like to post some more photos on here, I would love to see them!

Ah Shucks....

Now, back to our regular programming...

 

[sunchaser]

Ah Shucks....

Now, back to our regular programming...

Yup, Delfin and it's owner are not pretenders

 

[AusCan]

My old Volvo md17 was raw water cooled and ran at 140 F maximum, but the fresh water cooled versions used the same impellers and other parts. Only the thermostat was different.

 

[FF]

"My understanding of my keel cooler is that the engine runs with the thermostat closed until the correct temperature is reached then the thermostat opens and allows some cold keel-cooler coolant into the system to maintain the operating temperature."

This is how it works in over the road vehicles. The key difference is OTR have radiators that drop the coolant about 20-30 deg from the operating temperature.

This 20 deg drop does not shock the cooling system as the thermostat modulates.

Keel coolers are always sized for worst case use , tropical water , full throttle , growth on the cooler surface, so in normal operation the coolant returned can be 50 -100 deg lower than the engine water temperature.

Most thermostats have a difficult time with this .

By installing a bypass thermostat the keel cooler water is returned at 160F or so and the engine stays more stable.

 

[Ski in NC]

All engines circulate coolant through the block and head and the cold water from radiator or KC is blended in at the circ pump as needed to satisfy the thermostat.

On road vehicles running in northern winter at -20F that coolant coming out of the radiator will be COLD!! System still works just fine.

In converting the Yanmar from direct cooling (SW) to KC, he is not going to have the circulation bypass unless he builds that system in. I don't think that will be a big deal as the engine lived with no circulation when SW cooled. If that feature can be built in, then I would certainly do it. Just a little line connecting from near tstat to near impeller pump suction should do it.

 

[IRENE]

Keel Cooler Through-Hull Fitting Condensation?

Maybe a bit of thread drift...

I am observing a drip of something on my keel cooler through-hull connection. Sometimes it is there and sometimes it is gone (maybe evaporated). We recently adopted this boat, and I have not had an opportunity to evaluate closer, yet. This is my first keel-cooled boat. I have observed no other related symptoms and the engine temperatures (JD 4045TFM75) are running as they should.

Are those of you with keel coolers experiencing any condensation on the interior fittings? For temperature reference, I am in the Puget Sound area. Any advice/guidance is appreciated.

Thank You!

 

[Delfin]

Maybe a bit of thread drift...

I am observing a drip of something on my keel cooler through-hull connection. Sometimes it is there and sometimes it is gone (maybe evaporated). We recently adopted this boat, and I have not had an opportunity to evaluate closer, yet. This is my first keel-cooled boat. I have observed no other related symptoms and the engine temperatures (JD 4045TFM75) are running as they should.

Are those of you with keel coolers experiencing any condensation on the interior fittings? For temperature reference, I am in the Puget Sound area. Any advice/guidance is appreciated.

Thank You!

As soon as the engine reaches temperature the through hull fittings carrying coolant would be pretty hot so condensation would be unlikely. Before then, perhaps, so maybe that is what you are detecting.

 

[Conrad]

Just curious if you still have your Allweather boat and how you like it.

I'm also interested; have always liked the simplicity and nauticalness (Is that a word?) of the Allweather.

ALLWEATHERBOATS.COM

 

[Xsbank]

Sorry but there is no "shock" to an engine when the thermostat starts to open on a keel-cooled boat.

 

[FF]

Sorry but there is no "shock" to an engine when the thermostat starts to open on a keel-cooled boat.

Perhaps , it varies with the engines thermostat response time.

Simply watching the temp gauge will show if your engine drops 10-20 deg every s often.

The OP does need help to get some heat in the boat.

 

[Preston Briggs]

Most of the commercial trawlers are keel cooled, and dry exhaust. Again I would not have keel cool as the tubes are exposed and usually covered with growth. Yuck!

On my Allweather, the tubes are copper, which ought to keep down the growth.
Indeed, for best performance, I should avoid painting them
(since the antifouling won't help and the paint would act as an insulator).

I'll have to try my bright idea soon.

Preston

 

[FF]

"I was told that the rubber impeller will not last with hotter antifreeze/water mix"

When changing from direct sea water cooling over to a heat exchanges system it is common to use 2 paper gaskets to make up for the rubber expansion ..

Most KK systems simply use the installed water pump that is stock to the engine .

Higher temperature coolant should make the engine more fuel efficient , but it might be hard to measure.

The only downside if 140F coolant is it will not heat the lube oil warm enough to evaporate and blow-by.

No big deal, simply change the oil more often. And BEFORE winter storage

 

[ak-guy]

"I was told that the rubber impeller will not last with hotter antifreeze/water mix"

I was warned about Globe impellers used with hot coolant. Whatever they are made of is incompatible with high temps.