What general sailing practices do you know of that are commonly accepted, but aren't really what they're cracked up to be? Or on the other hand, what is commonly scoffed at as rubbish that in reality has merit? For instance, I was recently told that diesel engines should be warmed up before run hard, the reason being that the oil will sludge up (more quickly) if you don't. But I've also been told once upon a time that warming up at idle is not good for an engine. So, do you fire it up and shove off, or idle for a while to warm up first, or warm up at some moderate rpms?
Fact or myth
- Thread starter T37 Phil
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fire it up and shove off
it's a diesel. Ever see a farmer warm up his tractor? This should be fun...
it's a diesel. Ever see a farmer warm up his tractor? This should be fun...
Moderation in all things??
Exceeive idling is bad but running hard with a ice cold engine is also bad. After a little warm up then low power until warm. Big myth is that you should keep your diesel tanks full. This leads to old diesel and all sorts of truobles. Only keep in you tank what you will use in a few months or a season. Old diesel fuel is not a good thing no matter how much snake oil you add.
Exceeive idling is bad but running hard with a ice cold engine is also bad. After a little warm up then low power until warm. Big myth is that you should keep your diesel tanks full. This leads to old diesel and all sorts of truobles. Only keep in you tank what you will use in a few months or a season. Old diesel fuel is not a good thing no matter how much snake oil you add.
Hi Phil, most all diesel mechanics will tell you to...
fill up the tank when left for the winter. They tell me that condensation will form in the tank's open space and contaminate the fuel. The larger the space the more condensate created. Probably an old wives tale, but I still follow that rule. During the cruising season, which is year around in these parts, I fill the tank when I return to our slip, or at the next fueling station. As far as running the engine goes, I always start the engine before I raise anchor or remove the dock lines. By the time I'm ready to cast off I do so at moderate RPM as conditions permit. I normally cruise at 2,000 RPM, which is hull speed. Terry
fill up the tank when left for the winter. They tell me that condensation will form in the tank's open space and contaminate the fuel. The larger the space the more condensate created. Probably an old wives tale, but I still follow that rule. During the cruising season, which is year around in these parts, I fill the tank when I return to our slip, or at the next fueling station. As far as running the engine goes, I always start the engine before I raise anchor or remove the dock lines. By the time I'm ready to cast off I do so at moderate RPM as conditions permit. I normally cruise at 2,000 RPM, which is hull speed. Terry
Fire up and go
Took a course from Chris Oliver a well respected Annapolis based diesel mechanic who recommends firing up and taking off. As Terry already stated, by the time you fire up and raise anchor or slip lines a few minutes have passed. More than enough time to warm up a diesel.
Took a course from Chris Oliver a well respected Annapolis based diesel mechanic who recommends firing up and taking off. As Terry already stated, by the time you fire up and raise anchor or slip lines a few minutes have passed. More than enough time to warm up a diesel.
LIke most internal combustion engines .....
its not OK to run them hard or at full load until the engine has fully warmed up. If you go full throttle on a cold engine you can break valve springs, piston rings, scuff pistons/cylinders, and the oil galleries may not be operating up to full pressure and the oil will be 'thicker' so the main journal bearings will be 'floating' until all the clearances are 'up to temperature'. Sure its OK to 'move' with a cold engine just dont do it at wide-open-throttle or apply lots of load until its fully warm. An engine is designed to run at a fixed temperature (~180 deg. F), running it hard below that temp. is going to cause excess wear, etc. ... until all the components are at 'operating temp'. Just as bad is letting an engine warm up by idling it for a long time (although diesels are better at this than gasoline engines). Idling engines will take a looooooong time to get up to operating temperature ....... DRIVE the car, MOVE the boat; just dont 'beat it' until its fully warmed up and all the oil and mechanical clearances are at their correct dimensions 'at temperature', etc.. ;-)
its not OK to run them hard or at full load until the engine has fully warmed up. If you go full throttle on a cold engine you can break valve springs, piston rings, scuff pistons/cylinders, and the oil galleries may not be operating up to full pressure and the oil will be 'thicker' so the main journal bearings will be 'floating' until all the clearances are 'up to temperature'. Sure its OK to 'move' with a cold engine just dont do it at wide-open-throttle or apply lots of load until its fully warm. An engine is designed to run at a fixed temperature (~180 deg. F), running it hard below that temp. is going to cause excess wear, etc. ... until all the components are at 'operating temp'. Just as bad is letting an engine warm up by idling it for a long time (although diesels are better at this than gasoline engines). Idling engines will take a looooooong time to get up to operating temperature ....... DRIVE the car, MOVE the boat; just dont 'beat it' until its fully warmed up and all the oil and mechanical clearances are at their correct dimensions 'at temperature', etc.. ;-)
Warm up
For once I seem to be in the majority. I normally start mine and let it idle for a couple or three minutes. Enough to get oil circulating, pressure to all moving parts and the oil at least not stone cold. Then I'm off, at reduced throttle till it's fully warmed up. As for keeping the tank full, or not keeping it full. I live in a 12 month sailing area, and I buy fuel as needed.
For once I seem to be in the majority. I normally start mine and let it idle for a couple or three minutes. Enough to get oil circulating, pressure to all moving parts and the oil at least not stone cold. Then I'm off, at reduced throttle till it's fully warmed up. As for keeping the tank full, or not keeping it full. I live in a 12 month sailing area, and I buy fuel as needed.
Use your ears and whatever common sense you
might have. When the engine is running well and smoothly you can take the boat out of the slip. By the time you are in the clear then it is safe to advance the throttle but if you can't hit the ground running from a sound sleep don't expect it from your engine. Give it time to stretch and have the morning coffee before you demand too much from it.
might have. When the engine is running well and smoothly you can take the boat out of the slip. By the time you are in the clear then it is safe to advance the throttle but if you can't hit the ground running from a sound sleep don't expect it from your engine. Give it time to stretch and have the morning coffee before you demand too much from it.
Fact or myth --- Filling a diesel fuel tank up to prevent moisture in fuel
Hi Phil, Based on what I've read regarding engine oil changes in diesel engines, a 5 minute warm-up should be adequate to run a diesel engine at rated speed without any concern about damage due to the temperature of the lubricating oil. The recommendation generally made regarding filling the tank up at the end of the season to prevent moisture formation in the fuel has also been a concern of mine since it is almost impossible to use all the fuel in the tank over a season. At better than $4.00 per gallon, it is not at all pleasant to be dumping fuel because it is too old. If the fuel tank is resting on the bottom inside hull of the boat, it is likely to be about the same as the temperature of the water and hull. In our area, most leave their boats in the water all year and the temperature of the water pretty well tracks the ambient temperature of the air, except during the very coldest days of the year that dip below well below freezing and then the water only dips 45 to 50 degrees. The point of all this rambling is that it seems to me there is little chance for condensation under those conditions except maybe for the moisture that is in the air found in the fuel tank. Does anyone have any data that would indicate the moisture in the air found in a fuel tank that is about half full would seriously contaminate the fuel in the tank? Lamar
Hi Phil, Based on what I've read regarding engine oil changes in diesel engines, a 5 minute warm-up should be adequate to run a diesel engine at rated speed without any concern about damage due to the temperature of the lubricating oil. The recommendation generally made regarding filling the tank up at the end of the season to prevent moisture formation in the fuel has also been a concern of mine since it is almost impossible to use all the fuel in the tank over a season. At better than $4.00 per gallon, it is not at all pleasant to be dumping fuel because it is too old. If the fuel tank is resting on the bottom inside hull of the boat, it is likely to be about the same as the temperature of the water and hull. In our area, most leave their boats in the water all year and the temperature of the water pretty well tracks the ambient temperature of the air, except during the very coldest days of the year that dip below well below freezing and then the water only dips 45 to 50 degrees. The point of all this rambling is that it seems to me there is little chance for condensation under those conditions except maybe for the moisture that is in the air found in the fuel tank. Does anyone have any data that would indicate the moisture in the air found in a fuel tank that is about half full would seriously contaminate the fuel in the tank? Lamar
These guy's can't be relied upon. <g>
Phil: Don't take their word for it! Check with the experts. This is one of the better sites for Yanmar engines. It generally applies to all diesels.
Phil: Don't take their word for it! Check with the experts. This is one of the better sites for Yanmar engines. It generally applies to all diesels.
Gasoline engines shouldnt be idled for long....
the cylinder not being up to 'temperature' causes the fuel to condense on the walls of the cylinder plus a over-rich mixture for 'starting' will promote the unburned gasoline to wash any lubeoil at the piston rings from the cylinder walls. Not as bad on a diesel as #2 oil is a fairly decent lubricant.
the cylinder not being up to 'temperature' causes the fuel to condense on the walls of the cylinder plus a over-rich mixture for 'starting' will promote the unburned gasoline to wash any lubeoil at the piston rings from the cylinder walls. Not as bad on a diesel as #2 oil is a fairly decent lubricant.
Lamar .... FALSE
That moisture is 'condensing' on tank walls only means that the oil is fully saturated with water .... water vapor that gets drawn INTO the tank oil by 'chemical equilibrium'. Oil fresh from a cracking unit or diltilling column will have virtually ZERO water in it. Take the SAME oil put it in any container thats open to the atmosphere, wait long enough and the water will migrate from the wet atmophere to the DRY oil ... chemical equilibrium. If 'condensation' was the primary 'drive' ... we wouldnt need wells for water as all we'd have to do is put empty tanks all over the place and they would 'magically' fill up ... and you know that doesnt happen. The least amount of oil in the tank, the least amount of 'water uptake' and 'equilibration' to the constantly changing ambient conditions. Best is to EMPTY the tank during long term storage. A full tank has minimal 'merit' due to the small volume/ cross section of the vent line ... but equilibrium is still going to eventually saturate that oil with water if the oil is in contact with the 'atmosphere'.
That moisture is 'condensing' on tank walls only means that the oil is fully saturated with water .... water vapor that gets drawn INTO the tank oil by 'chemical equilibrium'. Oil fresh from a cracking unit or diltilling column will have virtually ZERO water in it. Take the SAME oil put it in any container thats open to the atmosphere, wait long enough and the water will migrate from the wet atmophere to the DRY oil ... chemical equilibrium. If 'condensation' was the primary 'drive' ... we wouldnt need wells for water as all we'd have to do is put empty tanks all over the place and they would 'magically' fill up ... and you know that doesnt happen. The least amount of oil in the tank, the least amount of 'water uptake' and 'equilibration' to the constantly changing ambient conditions. Best is to EMPTY the tank during long term storage. A full tank has minimal 'merit' due to the small volume/ cross section of the vent line ... but equilibrium is still going to eventually saturate that oil with water if the oil is in contact with the 'atmosphere'.
FWIW I've had my boat through three winters now
with never more than a quarter tank of diesel, never any evidence of water... Two winters ago I took the tank out to inspect it and clean it if necessary. I pumped the fuel through one of those funnel filter/water separators as I transferred it to a container, no water. My racor hasn't had any water in the separator either. I used to have a diesel Mercedes years ago and was told to just start it and go by the mechanics at the dealership. They all said just don't run it real hard until it's warmed up. But they said, once warmed up the best thing you could do for the engine was to run it hard. One sailboat myth I heard is that it's bad luck to have the color blue anywhere on the boat. Seems to me there are many boats with blue sail covers, hulls, stripes, cushions, etc. Manny
with never more than a quarter tank of diesel, never any evidence of water... Two winters ago I took the tank out to inspect it and clean it if necessary. I pumped the fuel through one of those funnel filter/water separators as I transferred it to a container, no water. My racor hasn't had any water in the separator either. I used to have a diesel Mercedes years ago and was told to just start it and go by the mechanics at the dealership. They all said just don't run it real hard until it's warmed up. But they said, once warmed up the best thing you could do for the engine was to run it hard. One sailboat myth I heard is that it's bad luck to have the color blue anywhere on the boat. Seems to me there are many boats with blue sail covers, hulls, stripes, cushions, etc. Manny
warm up in gear?
I've also heard that it's not good to run a diesel without a load on it. If I want to warm it up while it's in the dock, I put it in reverse. This puts a little strain on the dock lines, but the boat doesn't really move much. What do people think of this practice?
I've also heard that it's not good to run a diesel without a load on it. If I want to warm it up while it's in the dock, I put it in reverse. This puts a little strain on the dock lines, but the boat doesn't really move much. What do people think of this practice?
There were lots of myths concerning boats that we
rarely hear anymore. Don't use walnut on a boat. It's coffin wood. Don't start a voyage on Friday. I don't know why. It is bad luck to have women on a boat. As to diesel engines truckers and construction equipment operators just wait until the exhaust plume is clean before they get moving.
rarely hear anymore. Don't use walnut on a boat. It's coffin wood. Don't start a voyage on Friday. I don't know why. It is bad luck to have women on a boat. As to diesel engines truckers and construction equipment operators just wait until the exhaust plume is clean before they get moving.
My Yanmar Manual says that for my 3HM35F, etc. that...
...an engine should run for 5 minutes both BEFORE and AFTER a trip. BEFORE to warm and DISTRIBUTE the oil and AFTER to allow the engine to come down to operating temp because it may spike up when bringing it into a mooring or a slip thru acceleration techiniques used to bring it in. Makes sense to me. So I follow the directions and spend the 2 cents of fuel idling (up from 1 cent this year). But some engines may require certain care than other engines. Also, this includes 3GM30F, 2GM20F and 1GM10F engines, (Also shown in the SAME manual.
...an engine should run for 5 minutes both BEFORE and AFTER a trip. BEFORE to warm and DISTRIBUTE the oil and AFTER to allow the engine to come down to operating temp because it may spike up when bringing it into a mooring or a slip thru acceleration techiniques used to bring it in. Makes sense to me. So I follow the directions and spend the 2 cents of fuel idling (up from 1 cent this year). But some engines may require certain care than other engines. Also, this includes 3GM30F, 2GM20F and 1GM10F engines, (Also shown in the SAME manual.
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