Are we damaging our engine by just ticking over?

[Kassia]

Hello

We have a Nanny Diesel engine in our boat which powers our batteries but also heats our water. As we are yet to buy a generator we generally run the engine a couple of hours each night and then longer at the weekends to maintain the batteries. Normally we just have the engine ticking over but I wonder if this damages it long term? Is it best to vary what we do to ensure we are not causing any problems?

Thanks

Kassia

[tafelberg]

Yes I was wondering this I have a lister HRW2 and two people have told me opposite things in the last week! C&RT say I'm not allowed to run my engine in gear but the engineer I spoke to said I should run it in gear.

 

What do I do?

[Proper Job]

Generally speaking, it is not good to run a diesel engine on light loads and tickover for prolonged periods.

 

Propulsion engines are not ideal for battery charging (light load)

 

That said, many boats rely on the propusion engine to heat water and even more rely on it to charge batteries. It's not ideal, but that's all they've got.

 

Do not run your engine in gear when tied up.

[nicknorman]

You always consider actually going out cruising in the boat (steady on Tafely!).

 

I think if the engine is not new, it will already have bedded in and thus will be less prone to glazing especially if you use an appropriate oil. Probably best to run it a few hundred rpm above tickover and try to use it "properly" from time to time.

 

Running in gear is not allowed by your licence conditions and it can be very bad for the canal banks etc, though I suppose it depends on how you are moored - if on a pontoon with the stern well away from the bank, there is probably minimal impact.

[Keeping Up]

Most alternators charge better if the engine is run faster than tickover - by about 50% is good - and this also helps avoid any problems with glazing etc.

Definitely do not run it in gear when moored.

[Bee]

It`s generally accepted that to run an engine with little or no load for long periods is bad for it, glazed bores, oil sludging etc. but with a modern engine with an effective thermostat that allows it to reach a proper temperature and modern oils it might not be so bad. Personally I would still try to avoid doing it but if you have to it`s best to run it at a good fast tickover, it will help circulate hot oil and water properly and keep oil pressure up.

[Rebotco]

I was advised to run my engine (Isuzu 42) at 1000 rpm for optimal charging purposes. Any more adds little extra charging, plus uses more fuel. Any less drops the charging rate significantly.

But never in gear while moored.

[Nickhlx]

I was advised to run my engine (Isuzu 42) at 1000 rpm for optimal charging purposes. Any more adds little extra charging, plus uses more fuel. Any less drops the charging rate significantly.

But never in gear while moored.

 

Running at higher revs than idle also spins the alternator faster and helps keep it cooler..... whilst it may produce say max amps at what the battery will accept at say tickover, it will be better for the alternator to be spinning at say tickover + 50%, both for the engine and the alternator - fuel consumption will be minimally different

 

Nick

[Rebotco]

Running at higher revs than idle also spins the alternator faster and helps keep it cooler..... whilst it may produce say max amps at what the battery will accept at say tickover, it will be better for the alternator to be spinning at say tickover + 50%, both for the engine and the alternator - fuel consumption will be minimally different

 

Nick

 

 

That makes sense to me. Cheers.

[coventrylad]

As other have said, diesel engines work far better and feel happier under load, and should also be quiter under load, As for the speed of the alternator it is all done to to fly wheel / pulley ratio. if it is geared right you may well get max charge amps at a slower rpm, But you would really need to find the power curve of your alternator to obtain the most efficent rpm for maxium charge rate.If you have a rpm gauge on your engine the pulley ration and speed of your alternator can be worked out very simply. divide the diametre of your engine pulley by the diametre of the alternator pulley, this will give the gear ratio. so for any easy example if your engine pulley was 200m and the alternater pulley 50mm then you would have a ratio 4.1 so in lay mans terms if you engine is reving at say 500 rpm the alternater is going 4 times as fast i.e 2000rpm. then go back to the power curve and see what amps you are getting at 2000rpm. not a lot i guess. Sorry if i have rambled on a bit

[Nickhlx]

By "the most efficient alternator rpm" do you mean the slowest so fuel consumption of the engine is lowest ?

 

Regardless of that I would be far more concerned that the alternator would not self destruct through overheating if this could be avoided by running the engine a little faster and suffering the little extra fuel used - it would only be for a short time anyway, as much of the time taken to charge the battery bank is in putting the last 20% or less in...

 

Of course if the alternator was pullied up to be at peak output at tickover ( and not over-speed at max engine revs - unlikely) the above would not be necessary

 

Nick

[coventrylad]

No , i do not, If one was to look at the power curve for each alternator, it would give you the out put at a specified rpm and one could then run there engine at the correct speed for optium charge amps. Just because you may have a 140 amp alt, it will not of course give this ampage out at low rpm. With regards to self destruction of the alt, how could this possibly happen IF you have worked out the gear ratio and have the power curve to hand, which is what I suggested ? or you could of course just get a clamp meter and check the out put at varying rpm.

Edited January 11, 2013 by coventrylad

[Guest]

Most alternators charge better if the engine is run faster than tickover - by about 50% is good - and this also helps avoid any problems with glazing etc.

Definitely do not run it in gear when moored.

I don't use the engine for this purpose very often, but if I do, I find that running at around 1100 rpm (900rpm at tickover) increases the alternator output dramatically.

This is also in line with Vetus recommendation to me. They said it isn't kind to the engine/gearbox but if needs must, then raise the revs slightly.

[OldGoat]

The Nanni is based on a Kubota engine

These engine are designed for a variety of industrial uses - such as diggers, cranes and the like.

These run at idle for much of the day while their operators "do other things".

Any plant engine which had to be working busily all the time else it would fail would soon be thrown back at the manufacturer.

 

Now, the above may not be so true for older engines (though I have my doubts as modern engine oils cope with low temperatures better than their forbears),

but for industrial units this is no longer the case.

 

Just spin the engine at 1200+ rpm - it'll heat the water quicker and charfge the batteries ditto.

 

(You'll do more damage if you don't change the oil at reasonable intervals)

 

 

 

 

[OldGoat]

The Nanni is based on a Kubota engine

These engine are designed for a variety of industrial uses - such as diggers, cranes and the like.

These run at idle for much of the day while their operators "do other things".

Any plant engine which had to be working busily all the time else it would fail would soon be thrown back at the manufacturer.

 

Now, the above may not be so true for older engines (though I have my doubts as modern engine oils cope with low temperatures better than their forbears),

but for industrial units this is no longer the case.

 

Just spin the engine at 1200+ rpm - it'll heat the water quicker and charfge the batteries ditto.

 

(You'll do more damage if you don't change the oil at reasonable intervals)

 

 

 

 

[waterworks]

the people who tell you to run off load at tickover just don't know what they're talking about, thats why you still hear this old (canal) urban myth.

 

I think you will usually find the engines operator mananual tells you not to do this, and they do know a bit about it.

[Grace and Favour]

the people who tell you to run off load at tickover just don't know what they're talking about, thats why you still hear this old (canal) urban myth.

 

I think you will usually find the engines operator mananual tells you not to do this, and they do know a bit about it.

 

So what are you suggesting the OP should do?

 

Run in gear at tickover

 

or

Run higher than tickover?

[Tony Brooks]

The Nanni is based on a Kubota engine

These engine are designed for a variety of industrial uses - such as diggers, cranes and the like.

These run at idle for much of the day while their operators "do other things".

Any plant engine which had to be working busily all the time else it would fail would soon be thrown back at the manufacturer.

 

Now, the above may not be so true for older engines (though I have my doubts as modern engine oils cope with low temperatures better than their forbears),

but for industrial units this is no longer the case.

 

Just spin the engine at 1200+ rpm - it'll heat the water quicker and charfge the batteries ditto.

 

(You'll do more damage if you don't change the oil at reasonable intervals)

 

 

 

Also a reasonably sized alternator will probably load the engine more than travelling along the canal. People who say run in gear tend to forget that.

[waterworks]

So what are you suggesting the OP should do?

 

Run in gear at tickover

 

or

Run higher than tickover?

Buy a generator, and don't run a boats engine to charge batteries, wear out the geny not your engine. One costs a few hundred, and the other a few thousand, simples.

 

 

 

If you have to, run in gear at a rpm the engine is happy at, which depends on the engine.

 

Also a reasonably sized alternator will probably load the engine more than travelling along the canal. People who say run in gear tend to forget that.

 

23 amps per Hp, is a figure that one of the best high spec alternator manufactures work on.

[RLWP]

 

If you have to, run in gear at a rpm the engine is happy at, which depends on the engine.

 

 

Pardon?

 

Richard

[Tony Brooks]

Buy a generator, and don't run a boats engine to charge batteries, wear out the geny not your engine. One costs a few hundred, and the other a few thousand, simples.

 

 

 

If you have to, run in gear at a rpm the engine is happy at, which depends on the engine.

 

 

 

23 amps per Hp, is a figure that one of the best high spec alternator manufactures work on.

 

 

Which gives a load of just over 3hp for a 70 amp alternator. That is just abut the same as the figure quoted in an old WWW article about the power needed to propel a 60ft (ish) narrowboat along at canal speed. Accepted that as the charge drops so will the power taken but it will still be a reasonable load.

[waterworks]

Which gives a load of just over 3hp for a 70 amp alternator. That is just abut the same as the figure quoted in an old WWW article about the power needed to propel a 60ft (ish) narrowboat along at canal speed. Accepted that as the charge drops so will the power taken but it will still be a reasonable load.

 

doesn't sound right to me Tony, the words "waterways world" kind of give that idea a bad start , yea you could move along on 3 hp once you'd got momentum going, but you could get off, go to the caff, have a breakfast, and the boat would still be in sight !

 

and i don't think any usual multi cylinder narrowboat engine could run slow enought to put out 3 hp without stalling.

 

[Keeping Up]

doesn't sound right to me Tony, the words "waterways world" kind of give that idea a bad start , yea you could move along on 3 hp once you'd got momentum going, but you could get off, go to the caff, have a breakfast, and the boat would still be in sight !

 

and i don't think any usual multi cylinder narrowboat engine could run slow enought to put out 3 hp without stalling.

 

 

 

I've heard figures like 3 or 4 hp quoted in many places too. I believe them 100%. I am sure you would find that the boat copuld travel at a perfectly respectable speed with this amount of propulsion power.

 

It is easy for even a large modern engine to deliver 3hp of output. Imagine if you rev it up in neutral; it is delivering 0hp. You can then add any small additional load that you like and the engine will deliver the extra without any problem whatsoever.

[Nickhlx]

23 amps per Hp, is a figure that one of the best high spec alternator manufactures work on.

Is that at 24 volts or 12 volts ? ( nominal)

Nick

[ditchcrawler]

doesn't sound right to me Tony, the words "waterways world" kind of give that idea a bad start , yea you could move along on 3 hp once you'd got momentum going, but you could get off, go to the caff, have a breakfast, and the boat would still be in sight !

 

and i don't think any usual multi cylinder narrowboat engine could run slow enought to put out 3 hp without stalling.

 

Put it this way a donkey use to pull a loaded boat