Engine coolant

[NYSail]

Hello all...... I will be changing my engine coolant this winter and was wondering about different brands that people use. When I first bought my boat I switch from the green...... Flushed engine properly and used havaline extended life as recommended by Mac boring. All has been good. Just got my practical sailor and they review coolants and recommend heaven duty brands as best protection. Btw engine is a 3HM35F Thanks!

 

[Bill Roosa]

It really does not matter if you don't have an aluminum engine block, and most of us don't. Antifreeze never wears out but the water pump lubricants in it do so regular replacement is important to keeping this critical piece of equipment operational.

 

[Chris Patterson]

I use Rotella. Oil AND antifreeze. If it will live through the torture of a heavy truck pounding the roads, that's good enough for me. And it's not uncommon for these things to put 300 thousand miles a year on a left coaster. The oil may be dropped every 6000, but the coolant rarely..

 

[thinwater]

It really does not matter if you don't have an aluminum engine block, and most of us don't. Antifreeze never wears out but the water pump lubricants in it do so regular replacement is important to keeping this critical piece of equipment operational.

In modern coolant formulations water pumps are lubricated by dicarboxylic C8-C12 acids, and generally are present at 90% of original dose after vehical 100K miles.

Actually, heavy duty has to do with wet sleave liners vs. cast block and piston slap induced cavitation, not alluminum parts. It is a diesel issue. Google "liner perforation."

Honestly, in boats the biggest factor is contamination with seawater; the specification limit is 10 ppm and it is well known the >50 ppm can be very bad for some components. If I were going to test for one thing other than freeze point in a boat, it would be chloride (there are test tapes).

 

[Bob S]

In modern coolant formulations water pumps are lubricated by dicarboxylic C8-C12 acids, and generally are present at 90% of original dose after vehical 100K miles.

So if you average 50 hours per season then how frequent should one be changing their coolant out?

 

[thinwater]

So if you average 50 hours per season then how frequent should one be changing their coolant out?

Advice varies. 6-8 years, 12,000-15,000 hours. I've done fleet tests to 20,000 hours on transit bus engines. Hours are very seldom the issue.

However, the main concern for most boaters is seawater leaks. Just a few teaspoons of seawater changes everything. Short of coolant testing, watching for color changes (rust) is a good idea.

Premature failure will be one of 3 things:

* Seawater
* Exhaust leak (oxygen in the coolant) into coolant
* Electrolysis (bad ground)

 

[Stu Jackson]

Maybe that's the reason folks have raw water leaks on their boats: hoses, HXs, etc.

It's to change the coolant!

 

[Bill Roosa]

Hey thinwater
While I will applaud your understanding for chemistry, your knowledge of motors is a bit below the second standard deviation however.
Cavitation induced by piston slap???? You do know that cavitation is a liquid turning into its vapor state due to lowered pressure right?. do you realize how low the pressure of an oil has to get to make it turn to a vapor? Since there are no other liquids in the combustion chamber or on the pistons/connecting rods, I assume you are taking about the oil.
Aluminum block engines need specal anti. it has nothing to do with how heavy duty they are it has to do with the aluminum cooling passages not developing scale. and the liner does not even touch the anti in every engine I've seen.

 

[NYSail]

Sooooo..... guess I will take Practical Sailors advice and use a recommended heavy duty coolant for my system. Will do a flush prior to new stuff obviously. Figure will change the thermostat while I'm in there.

 

[Jan11]

{Snip} Aluminum block engines need specal anti. it has nothing to do with how heavy duty they are it has to do with the aluminum cooling passages not developing scale. and the liner does not even touch the anti in every engine I've seen.

Lots of other people know about Cavitation. For example: http://www.motorhome.com/rv-how-to/...to-know-about-diesel-antifreeze-and-coolants/

"Diesel motorhome engines fall into one of two categories when it comes to the engine block and the resulting type of coolant it requires. Smaller diesel engines such as the Cummins ISB and the Cat C7 are examples of dry-sleeve engines, which are more like typical automobile engines. Due to their design, these engines are not typically susceptible to cylinder wall cavitation, so they are not addressed in this article.
The larger diesel engines such as the Cummins ISC, ISM, ISL and ISX as well as the Cat C9, C11 and C13 all use wet-sleeve designs. These wet-cylinder engines allow the sleeve (that contains the piston) to come in direct contact with the coolant. Wet sleeves allow the engine to transfer more heat than dry systems, but because the iron sleeve is in direct contact with the coolant, they have some special requirements for their coolant/antifreeze.
Wet-cylinder diesel engines transfer a lot of vibration and movement from the pistons to the cylinder walls that can create coolant cavitation (tiny bubbles) behind the cylinder walls. Cavitation can ultimately lead to pitting of the cylinder walls from the outside in. Heavy-duty coolants formulated for diesel engines contain additives that deal with these tiny bubbles. Without getting too technical, it’s pretty clear that the coolant is important in these expensive diesel engines."

 

[Bill Roosa]

Really? So a wet sleeve cylinder vibrates less than a dry sleeve? Going to have to explain that one to me since the sleeve is cooled and the block heated to get it in and it is effectively a press fit that is one piece of metal.
The cavitation the article is talking about is the water pump impellers and the pitting is corrosion. Saw this quite a few times with old anti. My boss had standing orders to recommend a water pump replacement if we found old rusty anti in the car. Every time the pump came off with a pitted impeller. the pitting was in exactly the location where low pressure would be formed and looked "just like the pictures" you see of propeller cavitation damage.
FWIW

 

[Jan11]

Really? So a wet sleeve cylinder vibrates less than a dry sleeve?

Better read it again.

 

[thinwater]

Hey thinwater
While I will applaud your understanding for chemistry, your knowledge of motors is a bit below the second standard deviation however.
Cavitation induced by piston slap???? You do know that cavitation is a liquid turning into its vapor state due to lowered pressure right?. do you realize how low the pressure of an oil has to get to make it turn to a vapor? Since there are no other liquids in the combustion chamber or on the pistons/connecting rods, I assume you are taking about the oil.
Aluminum block engines need specal anti. it has nothing to do with how heavy duty they are it has to do with the aluminum cooling passages not developing scale. and the liner does not even touch the anti in every engine I've seen.

Google it. I am correct. This effect has been well known in the diesel industry for 40 years.

Water pumps cavitate too (Google it), but the additive solution is somewhat different.

http://penray.com/cooling-system-techfacts/cavitation-in-cooling-sytems/

As for aluminum blocks, cylinder heads, and radiators, each represents a slightly different problem. Some heavy duty coolants are not so good with aluminum blocks, but you won't find those in a marine diesel, I believe. If yes, G05 would be an excellent choice (nitrite free).