Turning engine over in the winter.

[tidclacy]

Reading a article about laying up engines for the winter, it mentioned that if you are leaving your boat in the water then turn over your engine every few weeks.

Why and is it necessary?

 

[DHV90]

Can help with any engine not moving for a long time to stop the rings gumming up and fusing to the cylinder bores (after a really long time), also all the oil will drain to the sump so when you next start up some parts will have been sat in oil and others will have mostly dried out so rotating parts in the oil can theoretically help but in real life this is unlikely to make much difference, just one of those things that some people do because there is a logical argument that it could help, even if it won't necessarily make any difference. On any engines in any vehicle I've had that have sat for a while I will turn them over if im in the garage or on the boat but won't make a special trip to do it.

 

[RAI]

I believe it is to recoat the lubricated surfaces with oil that has drained off while standing idle.

 

[Vara]

I've been told that, and run my engine under load at least once a month for half an hour, in reverse if tied to pontoon.

Cant do any harm, minimal cost, can't see a down side.

 

[pvb]

I've been told that, and run my engine under load at least once a month for half an hour, in reverse if tied to pontoon.

Why in reverse? I run the engine in forward gear, every few weeks in the winter, until it gets up to a decent operating temperature (say 15-20 minutes). It helps to get rid of condensation. I can't see that running it has any real benefit regarding oil draining down, as it'll drain down quickly anyway.

 

[prv]

I guess turning it over by hand can't hurt and might help, if it has a handle to do so. But starting it up for a few minutes' idling is exactly what diesels don't like, so don't do that.

I always left Kindred Spirit's well alone after laying it up, even though it did have a handle. The new engine on Ariam has no handle, so I will definitely leave that alone too. I expect it to start on the button in the Spring.

Pete

 

[Vara]

Why in reverse? I run the engine in forward gear, every few weeks in the winter, until it gets up to a decent operating temperature (say 15-20 minutes). It helps to get rid of condensation. I can't see that running it has any real benefit regarding oil draining down, as it'll drain down quickly anyway.

No, it's a fifty/fifty choice, to allow it to get to temp quickly, putting a load on is allegedly better for the engine.

 

[pvb]

No, it's a fifty/fifty choice, to allow it to get to temp quickly, putting a load on is allegedly better for the engine.

No "allegedly" about it, the engine certainly needs running in gear, and at reasonable revs. I just think that most installations run more sweetly in forward gear than in reverse, so wondered why you favoured reverse.

 

[prv]

I just think that most installations run more sweetly in forward gear than in reverse, so wondered why you favoured reverse.

If I was running Kindred Spirit's engine at the berth for some reason, I generally did it in reverse. Reason being that if I'd been in forward and the bow spring had given way for some reason, I'd have collided with the motorboat in front. If the stern spring had let go under reverse, I'd have sagged back into clear water. Engine seemed happy enough with either.

Pete

 

[glenp]

On the inland waterways it's fairly common practice to run in reverse when tied to the bank. Often there'll be another boat immediately behind so it avoids stiring them up too much. My view is if you are running the engine in gear take it as it comes for the particular circumstances!

 

[Hadenough]

No "allegedly" about it, the engine certainly needs running in gear, and at reasonable revs. I just think that most installations run more sweetly in forward gear than in reverse, so wondered why you favoured reverse.

Genuine Q. Why should an installation run more "sweetly" in forward than reverse?

 

[pvb]

Genuine Q. Why should an installation run more "sweetly" in forward than reverse?

I think it's primarily to do with prop design.

 

[ripvan1]

No "allegedly" about it, the engine certainly needs running in gear, and at reasonable revs. I just think that most installations run more sweetly in forward gear than in reverse, so wondered why you favoured reverse.

Always meant to ask why a boat diesel should be run under load, I've used many different plant machines and sometimes they're running all day and a lot of time will not be under load

confused dot com

 

[pvb]

Always meant to ask why a boat diesel should be run under load, I've used many different plant machines and sometimes they're running all day and a lot of time will not be under load

If the purpose of running it is to heat it up and get rid of condensation, it needs to get hot. Running it under load achieves that more quickly.

 

[michael_w]

If its been standing for a while it's not a bad idea to turn the engine over for a few seconds with the stop cable pulled. Gets the oil round the engine before it gets stressed starting.

 

[vyv_cox]

I cannot see any benefits whatsoever in running an engine during the winter simply to 'check that it is OK'. Why wouldn't it be? Provided the oil has been changed before laying up any corrosion in the engine will be minimal. Bearings won't corrode anyway, journals are not exposed to air so will be fine. Bores could theoretically corrode, but they are pretty much oil free within minutes of stopping running. They don't routinely corrode unless left wet from condensation and/or short runs.

Far better to take the normal precautions at end of season then plug the inlet and exhaust with rags to keep damp out and leave alone until spring.

 

[Ruffles]

On the inland waterways it's fairly common practice to run in reverse when tied to the bank. Often there'll be another boat immediately behind so it avoids stiring them up too much. My view is if you are running the engine in gear take it as it comes for the particular circumstances!

Prop is also much less efficient in reverse. So less strain in cleats and lines.

 

[sailorman]

Prop is also much less efficient in reverse. So less strain in cleats and lines.

Mine is the same both ways & no engine stop cable

 

[Lakesailor]

If its been standing for a while it's not a bad idea to turn the engine over for a few seconds with the stop cable pulled. Gets the oil round the engine before it gets stressed starting.

Diesels work at pretty high compression ratios, so even without fuel they hammer the bearings a bit. You need to make sure the oil pressure is picking when using the starter. Some engines don't pick up oil pressure until they are running a bit quicker.

With petrol engines I've rebuilt or haven't been run for a while I always whip the plugs out and whizz it over on the starter until oil pressure shows. Without compression the starter will turn it over much more quickly and there's less chance of picking up a bearing through lack of oil.

 

[tidclacy]

I cannot see any benefits whatsoever in running an engine during the winter simply to 'check that it is OK'. Why wouldn't it be? Provided the oil has been changed before laying up any corrosion in the engine will be minimal. Bearings won't corrode anyway, journals are not exposed to air so will be fine. Bores could theoretically corrode, but they are pretty much oil free within minutes of stopping running. They don't routinely corrode unless left wet from condensation and/or short runs.

Far better to take the normal precautions at end of season then plug the inlet and exhaust with rags to keep damp out and leave alone until spring.

That's what I thought, having loosened the drive belts and removed impeller, flushed fresh water through etc it seemed a bit counter productive to do it all again every few weeks.

When ashore it is not normal practice as far as I know and that was my question why different if in the water?