How often to start the engines?

[Hippocampus]

Under load is a very different thing then idle. Sitting winterized or just sitting after an oil/filter change is a very different thing than sitting with used oil (acids in it) .
Was told for engine life (natural aspiration or common) change oil/filters before long periods of non use. Periodically run at at least 80% load for awhile to make sure everything is in order. With N/A more important to burn off carbon. Told not an issue with common rail which may do better if sitting for a long time.
Had a Cape Dory 25 on a mooring. I could sail off/on the mooring so one season didn’t run the engine the whole season. When in the fall it came it was time to use the diesel engine to get to the hydraulic trawler to get to my yard. It over heated. I could run it briefly then stop to cool and then had it pulled in to get it on the trailer. Taking a look see there was hard growth including shell fish in the cooling system. No active growth inside ( no light or oxygen.)
Same reason when ever I’m on the current boat while tied up I run my thrusters. Just getting them to spin helps get growth off them to my logic. Water does puddle in spots internally when a boat isn’t run for a long time. Maybe less if you close intake and exhaust through hulls. To my thinking running it briefly under load to run water through the cooling system may help the anodes do their job. Never heard of confirmation of my thinking but several old salts told me. Change oil before letting it sit. Run it hard occasionally if sitting in the water for long times. Good to spin the shaft, prop and tranny as well for growth and prevention of oxygen starvation.

 

[Don L]

Guess no one here has engine oil analysis from before docking and after sitting at the dock and starting the engines once in a while

I wonder how the fuel in the oil results change

 

[Bacchus]

Sitting winterized or just sitting after an oil/filter change is a very different thing than sitting with used oil (acids in it) .

I continue to be amazed at how often I see this reasoning.
Lube additives include a base that neutralizes acids. Lube analysis includes measuring the level of TBN ( Total Base Number) which indicates how close the additive is to no longer being effective at neutralizing acids.

Also... for the how often to run question...
even if the oil is slightly acidic is it better to run it frequently and distribute through the engine or leave it sit and have it drain down leaving little in the engine and more in the pan??? Short runs and runs w/o load run more risk of building up moisture and products of combustion in oil IMO

I believe that if sampling & reliable analysis is good enough for managing oil changes on OTR truck fleets... its good enough for me & my diesel maintenance. These guys are generally shooting for 1 million miles between rebuilds.

 

[Phil Fill]

I'm a liveaboard in Florida. Just went from a 31" sail to a 36 Prairie Boatworks 36" trawler with twin Perkins 4's.
I don't have a lot of desire to cruise on the weekends. The boat is my home and my office and I see something going wrong out there that tends to keep me at the dock (sad ... I agree). My question is how often should I start my engines and let them run for a while? I started the sailboat (Yanmar) once a month and let it run for 15 minutes, brought it up to full throttle a few times and used the recommended shut down procedure from Yanmar.
Any feedback would be appreciated. These engines have sat for over two years but they started immediately and purr. Trainees are tight. I also cycle these when I run the engine. Thanks! Bob in Punta Gorda, FL.

Perkin is a great engine with a long history. Our 1978 gen set is Perkins.

We been a live aboard for 34 years. Boat was wedding present to ourselves. Before we retired the diesel engines where started every other month and run under load until up to temp, tied to the dock and in gear. Now that we are retired and land cruise, when we get back. The longest is 7 months. They start right up.

Do not run diesel engines very often with no load and not up to temp. Better to not start them. To get up to temp, might have tie boat to dock and in gear.

 

[Southern Boater]

Yup.

Had 4 motorcycles at one time, now down to 2 and soon to 1. Triumph Bonneville.

Never going to sell my Bonnie. Sometimes I just hop on in the garage and dream of a winding road -

I’m hearing you DR, I’ve got a 2005 Bonnie and feel the same, we rode them as kids in the 70’s.
If you find yourself wasting time on FaceBook Reels, and your search history on YouTube has been Triumph Bonnieville, the reels pop up with rides through twisting country roads from “helmet cam” and the truely magnificent sound of the Bonneville open or minimally baffled exhaust.

 

[Ken E.]

My diesels do just fine sitting for 6 months in the barn over the winter. They start immediately when we launch. I do not like running them at the dock without getting underway to actually heat them up.

I'm with you and the others who leave them cold for the winter. Oil change and winterize in November, start them in May the following year. Never a problem. Three boats, 50 years using this practice.

 

[ancora]

We run our twin engine boat in the slip by using the "H" maneuver. This puts a load on the engines but no load on the dock.

 

[Bacchus]

We run our twin engine boat in the slip by using the "H" maneuver. This puts a load on the engines but no load on the dock.

Can you elaborate on the H maneuver...

 

[rslifkin]

I'm with you and the others who leave them cold for the winter. Oil change and winterize in November, start them in May the following year. Never a problem. Three boats, 50 years using this practice.

Same here. We launched for the season last week. Engines had been winterized since late October and fired right up as expected on launch day.

 

[ancora]

Can you elaborate on the H maneuver...

To move a twin screw boat sideways to port: with engines at idle, turn the wheel all the way to starboard. Place the starboard shifter forward, the port shifter to reverse. To move the boat to starboard, turn the wheel all the way to port, place the port shifter in forward, the starboard shifter in reverse.

 

[rslifkin]

To move a twin screw boat sideways to port: with engines at idle, turn the wheel all the way to starboard. Place the starboard shifter forward, the port shifter to reverse. To move the boat to starboard, turn the wheel all the way to port, place the port shifter in forward, the starboard shifter in reverse.

This is not a universal method for twin screw boats. It works on some, but not others and on some boats doing that at the dock would still put significant load on the dock lines.

That method doesn't work in any useful capacity on my boat, for example. I've tried to use that maneuver to slide the boat sideways off a dock and the best you can do it moving diagonally forward (but still with more forward motion than sideways). Doing it to starboard with the rudders hard to port it required the stbd engine in idle reverse (~700 rpm) and with the port in forward I had to throttle that side up to about 1100 to avoid the boat just pivoting against the rudders and pushing the stern into the dock. A whole bunch of noise and prop wash to produce a slow diagonal forward motion at an angle of maybe 30* away from the dock (with the boat staying parallel to the dock). I very quickly wrote that off as being completely useless from a boat handling perspective and wouldn't bother trying it again on this boat.

 

[Bacchus]

To move a twin screw boat sideways to port: with engines at idle, turn the wheel all the way to starboard. Place the starboard shifter forward, the port shifter to reverse. To move the boat to starboard, turn the wheel all the way to port, place the port shifter in forward, the starboard shifter in reverse.

OK Thnx for clarifying. I and many owners here are singles so not applicable. Also, I would not consider "loading" at idle fanciest to bring a diesel to normal operating temps req'd to get the benefits of periodically running diesel engine(s).

My thinking us... if you don't run it up to normal operating temps (engine & oil NOT just coolant) for 20 -30 mins, don't bother running it. But that's just me... everyone gets to choose their practices.

 

[SteveK]

To move a twin screw boat sideways to port: with engines at idle, turn the wheel all the way to starboard. Place the starboard shifter forward, the port shifter to reverse. To move the boat to starboard, turn the wheel all the way to port, place the port shifter in forward, the starboard shifter in reverse.

I use this method to do a 180 spin on a dime with both slightly higher than idle. Will have to try some throttle differences to see if it will squarely go full sideways though.

 

[rslifkin]

I use this method to do a 180 spin on a dime with both slightly higher than idle. Will have to try some throttle differences to see if it will squarely go full sideways though.

A tight 180 spin and the sideways move are similar use of engines and rudder, but the direction of rudder use is opposite. For a tighter / faster spin than engines only you apply rudder towards the engine that's in reverse, for a sideways move you apply rudder towards the engine in forward (toward the side you want to move away from).

 

[SteveK]

Aha, I will give that a go, thanks

 

[ancora]

Previous to this semi displacement hull, we had a planing hull (no keel) where the "H" maneuver worked even better.