Advice running engine

[arch007]

Boat is in slip.

How often should I run engine at slip so engine does not dry out ?

Thinking once a month for 15 mins in neutral then 5 mins in gear.

OK ?

[denverd0n]

No. You would be better off taking the boat out every 3-4 months and running it for a half hour or more under a meaningful load. If you can't do that, then you should probably pickle the engine and just let it sit.

[MV Wanderlust]

Originally Posted by denverd0n

No. You would be better off taking the boat out every 3-4 months and running it for a half hour or more under a meaningful load. If you can't do that, then you should probably pickle the engine and just let it sit.

Agreed

[Mirage35]

I'm curious what in the engine can be damaged by "drying out".

Like everyone else in this area I leave the boat on the hard for six months of the year, then start the engine in the spring. I've never heard of this causing a problem.

[gonesail]

i thought pickling was for engines and outboards that have been submerged

[denverd0n]

"Pickling" is also the term used for the process of putting an engine into long-term storage.

[a64pilot]

I see nothing wrong with what he is wanting to do, it’s pretty much what I do. Unless you have a big motoryacht you can easily get a motor up to temp in gear at the dock.
I don’t see the difference in 1800 RPM tied to the dock or underway from the engines perspective.

I’ve never seen a sailboat motor pickled, never heard of it, I think maybe people don’t understand what pickling consists of, although there is no real definition.
Military does however and has had at least since WWII a list of how to preserve motors.

I have my little airplane’s engine pickled now.

[a64pilot]

Originally Posted by AnglaisInHull

I'm curious what in the engine can be damaged by "drying out".

Like everyone else in this area I leave the boat on the hard for six months of the year, then start the engine in the spring. I've never heard of this causing a problem.

One thing that can happen is the cylinder bores form a coating of rust, then as the engine is run it’s quickly cleaned off and gets into the oil, repeat often enough and you have polished bores, it’s probably the most likely way to get to polished bores in fact.
Plus the rust that gets cleaned off is pretty abrasive.

I’m pretty sure that cold weather up North In winter drops the humidity to a point to where rust doesn’t happen as quickly as say Summer in hot, muggy Florida.

Frequent operation hopefully leaves a coating of oil on the cylinders, over time of course it drains off, the argument is how long does it take to do that, and for rust in the engine to form? I don’t know.

Many will put a container of desiccant on the crankcase vent of an airplane engine, that way any air sucked in the the engine is dehumidified, in the hope to prevent internal rust. The Lycoming engine for example has its camshaft up high in the motor and suffers from cam rust on motors infrequently used.
Point being that sitting up in humid environments is hard on a motor, and boat bilges are often humid, especially in the warm South.

[Mirage35]

Thanks, pilot, that clarifies - true that the humidity over winter here is not a problem in that sense.

[mvweebles]

Get it up to operating temp and run for a good 15-minutes. I've never heard of pickling a diesel engine either. Last time I heard of that was a Bonham's Auction rare/antique Porsche that was being sold out of an estate. PO was a collector and had a back-up engine that had been properly pickled 40-years prior, including bearings that had been removed and stored in an oil bath. Whole package was worth a ton of money.

You have to really work hard to kill a diesel. Exercising it monthly/quarterly does more for the soul than the engine. It's a guy thing I suppose. Use your boat, don't sweat the small stuff. Don't let it sit for months and months, but don't get too anal about running monthly. Unless it's an excuse to get out of the house - by all means, absolutely critical to do.

Peter

[Mirage35]

Originally Posted by mvweebles

...

Unless it's an excuse to get out of the house - by all means, absolutely critical to do.

Peter

[slug]

Originally Posted by denverd0n

"Pickling" is also the term used for the process of putting an engine into long-term storage.

Fogging oil

I see it used, but have never used it myself

Probably s good idea for boats up north that get hauling and winterized for six months

The normal shut down procedure I use is to service the engine , flush out sea water and electrically isolate the engine

[a64pilot]

Fogging oil is one thing, but there is a special preservative oil, the fuel system should be purged and filled with preservative oil, and the air intake and exhaust blocked off and the crankcase vent as well.
A wet exhaust motor should have its exhaust disconnected from the wet exhaust and blocked off.
Those are steps that come to mind, but true picking is often removal of the engine, all those stops taken and it stored in a “can” that is hermetically sealed and has desiccant packages in it to remove all moisture.
But there is as far as I know no actual definition of what pickling is and it’s likely not even really a term.
Military aircraft (Army) usually had three types of storage, flyable storage, where it’s still flyable, short and long term.
Motors were always “picked” for long term which meant for turbines being washed internally and externally, preservative oil and the fuel system purged with 10/10 oil.

[rslifkin]

For winter storage on my (gas) boat engines, I do as follows: Change the oil. Flush the raw water side of the cooling system with antifreeze (which also means there's no corrosion causing water in the exhaust system). Right before final shutdown, blast fogging oil into the intake until it chokes for a couple seconds or stalls to get some extra oil on the cylinder walls, etc. Fogging process would be a bit different for a diesel, but the same concept applies.