Do you run your engines?

[GalaxyGirl]

Hello all,
I live in Boston and have a Hatteras motoryacht with 12v71ti's. I have heard conflicting views as to whether or not to run the engines once a week
for a half hr while at the dock through the winter. I do keep my block heaters on all the time. Any thoughts?


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[a64pilot]

First do not run your block heaters all the time. The reason is it will cause condensation inside the engine block, it's far better to leave them off, but turn them on several hours before you expect to use the engines. It may take most of a day to heat those big engines.

Running engines has been argued forever. I'm in the camp that says don't run them, unless you can put them under a load and bring them up to operating temperature.

Google "diesel stacking" or "wet stacking" to get a better idea as to why not.

[ranger58sb]

I don't idle at the dock; our engines won't come up to proper operating temps for quite a long time, that way, generally not within a half-hour.

(Our normal protocol is start engines, release lines, leave slip, idle out of the speed-limited zone... once temp gauges show some progress, increase throttle slightly to about 800 RPMs... so 10-15 minutes have gone by with the engines under load... and then maybe 10 minutes after that, our temps come up to where we can think about going faster. Or not.)

Our 450s are different from yours, though, and certainly most of the sailors here don't have big Detroits... so I'd rely more in guys who know your DDs well.

-Chris

[GalaxyGirl]

Originally Posted by ranger42c

I don't idle at the dock; our engines won't come up to proper operating temps for quite a long time, that way, generally not within a half-hour.

(Our normal protocol is start engines, release lines, leave slip, idle out of the speed-limited zone... once temp gauges show some progress, increase throttle slightly to about 800 RPMs... so 10-15 minutes have gone by with the engines under load... and then maybe 10 minutes after that, our temps come up to where we can think about going faster. Or not.)

Our 450s are different from yours, though, and certainly most of the sailors here don't have big Detroits... so I'd rely more in guys who know your DDs well.

-Chris

Ok thanks Chris, good point.


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[GalaxyGirl]

Originally Posted by a64pilot

First do not run your block heaters all the time. The reason is it will cause condensation inside the engine block, it's far better to leave them off, but turn them on several hours before you expect to use the engines. It may take most of a day to heat those big engines.

Running engines has been argued forever. I'm in the camp that says don't run them, unless you can put them under a load and bring them up to operating temperature.

Google "diesel stacking" or "wet stacking" to get a better idea as to why not.

Wish I didn't have to keep the block heaters on all the time but the temps here are miserable all the time


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[Maine Sail]

Originally Posted by GalaxyGirl

Wish I didn't have to keep the block heaters on all the time but the temps here are miserable all the time


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Here in Maine we simply winterize the engines... Just did a pair of 671's last week... This way if power is lost the engines don't freeze.

[a64pilot]

Originally Posted by GalaxyGirl

Wish I didn't have to keep the block heaters on all the time but the temps here are miserable all the time


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Your saying they would actually freeze if you didn't? That's out of my experience base there, I would have thought is a boat sitting in the water, that would be hard to do.

If that's the case and you didn't want to winterize, then I would heat the engine compartment, surely it wouldn't take much heat?

Ranger has a good point, but some of us sailor types grew up on big Sportfishermen, truth is I'm still more comfortable with big power boats as that is my experience, but I'm getting used to the little tiny motor in my sail boat, it's a cute little thing.

Still stacking can occur in cute little Diesels too, principle is the same.
Sailboat motors are just like Diesels, only smaller

[Sailmonkey]

I've never heard block heaters allowing condensation in the engines.....being warm precludes condensation.

As far as running them for a half hour with no load......bleh, those Detroit 2 stroke beasties will quickly become drooly messes without proper loading. Not something you can get at the dock. I may consider shutting off the seawater and rolling them a few times once a month with the starter to keep everything moving though.

I may be a sailor but I went to a maritime college for marine engineering.


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[Cuttyhunk]

Why aren't you winterizing them? I don't usually leave a boat in the water over the winter, but when I do, I still winterize the engine. All the winter liveaboards at my marina do that. If they decide to go out for a spin, they just do it again when they get home. It doesn't take long once you know how. If your marina loses power, you could have a very expensive problem on your hands.


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[a64pilot]

I've seen a few aircraft engines damaged by leaving heaters on all the time. You don't get condensation except when there is a difference in temperature, if the engines are at the same temp as the air around them, no condensation.

[thinwater]

Originally Posted by a64pilot

Your saying they would actually freeze if you didn't? That's out of my experience base there, I would have thought is a boat sitting in the water, that would be hard to do.

Absolutely will freeze, even mid-Chesapeake. The through-hulls won't freeze, but everything else will. I get frozen water bottles all the time.

[DeepFrz]

Leaving a block heater on will not cause condensation in the engine. As a matter of fact my owner's manual for my new Altima states that I should have the block heater on anytime the temp is below -7 c.

Winterizing the engines is indeed a good idea if you are not going to run the boat regularly in the winter, at least once a month, preferably once a week. Here is one link to an article on winterizing marine engines.
Boat Maintenance Tips - Winterizing a Boat Engine

[Sandero]

GG,

First, One of the Hatteras's that you didn't buy is parked in the slip next to me! How funny is that!

Second, why not winterize the engine? If the block and hose remain above freezing you should be OK.... But in the case of a shore power loss you are left with using your diesel fired system not only for the cab, but to keep the engine and hose from freezing. This may mean you need to run your generator to support your batteries.

I store in water and winterize the engine... and do an oil and filter change when I do. I don't think diesel engines are happy to run at idle with no load and it's to be avoided if possible. My Penta has been working fine since '85.... a little smokey from cold starts in cold weather but when the block warms up she's fine.

[ranger58sb]

Originally Posted by ranger42c

Our 450s are different from yours, though, and certainly most of the sailors here don't have big Detroits... so I'd rely more in guys who know your DDs well.

Originally Posted by a64pilot

Ranger has a good point, but some of us sailor types grew up on big Sportfishermen, truth is I'm still more comfortable with big power boats as that is my experience, but I'm getting used to the little tiny motor in my sail boat, it's a cute little thing.

Still stacking can occur in cute little Diesels too, principle is the same.
Sailboat motors are just like Diesels, only smaller

Originally Posted by Sailmonkey

I may be a sailor but I went to a maritime college for marine engineering.

Didn't mean that as a criticism, just that many here (but obviously not everybody) only have experience on engines smaller than GG's generator, often (but not always) 4-strokes vs. 2-stroke Detroits.

Originally Posted by Maine Sail

Here in Maine we simply winterize the engines... Just did a pair of 671's last week... This way if power is lost the engines don't freeze.

Yep, would think this is likely the best course of action. We winterize our main engines here on the Chesapeake... and would do so even if we lived aboard.

And we winterize the genset. Not sure how I'd want to handle that if living aboard, though. Nice to have immediate emergency power. OTOH, un-winterizing is as simple as opening the sea-cock and starting the motor... so it could still be available for emergencies "relatively immediately."

-Chris

[clyde]

conflicting views! there are those that know, and those that don`t!! you`re doing more damage than you think! never, ever ever, run any engine at the dock like that! the only way to run them, is away from the dock, with a good load, for 2 or 3 hours each time! otherwise they don`t warm up, just let them sit!! nothing will happen to them...i repeat, "NOTHING" will happen to them while just sitting! don`t try to get info of this kind from the 'dock dummies' that know nada! i repeat...let them just sit for 2 or 3, or 4 months, or as i first said, take them out for a good run! all your doing is making some hot water! another subject is oil...go check 'bob is the oil guy/motor oil 101 website
...i have a 35 yr old volvo, and use straight weight exxon/mobil #30...those that sell this oil to commercial fishing boats, will ask what engine you have, and give you the correct oil for that engine! as for a multi grade, i would use 10/30! do some reading on that site...clyde