Engine warm up.

[Deleted member 478]

There we were, pouring beer down our throats, and him, of Greek God fame, says something along the lines of (in an accent which is difficult enough to understand - especially if you have use Greek God's name as a username and you're a taffy) "I don't understand sailors that fire up their engines and move off within a few minutes. I warm mine up for at least 30 minutes before moving off".

"Well", says the Gringo on Stingo, in a knowing sort of way, "A diesel engine loves a load and if you're doing nothing more than idling, you'll clog up the art-cherries with muck and carbon and foot prints and and and...".

"Not so" says he, in a more knowingly Godly Greek manner. "You'll rip it to pieces in no time at all, because those pissed-ons and pissed -offs are not near enough lubricated; unlike you and I".

"Ah", says I. "Is this not an austerity measure to consume more diesel so that the plebeians have work"?

.... and so the conversation went around and around, in pointless revolutions per minute, warming up not only the environment, but also the discussion.

Please settle this for us, oh great diesel gurus; what should it be - a few minutes or a several litres of diesel burnt in warming up the en-wino-ment?

 

[penfold]

Startup and if the idle is stable go; the devil clogs up idl(ing) engines. No idling is required, nor does it do any good as diesels idling warm up slower than a scottish summer.

 

[vyv_cox]

There is a bit about this on my website for perusal in more detail.

Warming up slowly is probably the major cause of bore glazing, due to condensation of combustion products. We don't hear a great deal about this problem nowadays with reductions in sulphur levels in both fuel and lubricant but it probably still occurs. Every authority that has ever pronounced on diesels advocates getting them under load immediately to ensure maximum heating rate.

The lubrication statement is simply not true. Bores and pistons are lubricated in most engines by a squirt from the top of the big end bearing. This is at lub oil pressure through a small hole, so it hits the bore with some violence. Having watched engines start up through transparent ports I can assure your drinking partner that the crankcase is awash with oil as soon as the engine starts.

Warming down is said to be helpful after a long run, to stabilise temperatures across the cylinder head. I let the engine tick over for a couple of minutes, which supposedly helps to prevent carbon deposits in the combustion areas.

 

[Iliade]

+1

Reasons not to set off straight away include:

- Giving the water pump/diesel supply five minutes to see if it keeps working.
- Giving yourself enough time to check for leaks etc.
- 5 minutes warm up on load if you will need full throttle to avoid the new low bridge 30m upstream from the mooring, the spring flood runs like Red Rum and the boat turns to port when going astern out of the riverside pier.


Otherwise, start and go, but at less than full throttle.

 

[Blueboatman]

More reefer units, tha's the answer, more compressors. Shed load of ice making, beer coolin, thirst slakin, cocktail dressin, glass freezing, idle skipper drinking available as soon as you turn the key .

I would def remove the gearbox and propellers though, that's just more stuff to go wrong.

 

[oldharry]

Reckon Penfold and Viv-cox running equal on this. Diesels run much cooler than petrol engines, so warm up slower. Result is uneven warming of the cylinder head and block if left ticking over from cold. Done regularly this can cause the gasket to fail prematurely as the head develops localised 'hot spots'. In the bores as Viv points out condensation can play havoc until they are properly warmed. The few minutes warm up after starting and moving off, this effect is minimised. Leave it on tick over for 20 minutes every time has the cumulative effect of 10 or 15 cold start wear cycles each time!

 

[maby]

I certainly will not warm up for half an hour, but several minutes - yes.

Last winter in the marina we watched with a morbid fascination as some flash idiot jumped into a moderately large mobo, started the engine, dropped the mooring lines and gunned it out of the finger berth and into the aisle. He then shoved it hard into reverse to stop before he hit the boat at the end of the aisle and promptly stalled... This was followed by strong cursing and wild attempts at getting it to fire up again - he managed with seconds to spare and missed the other boat by inches!

Never forget - we rely on them to stop as well as to go - and a failure to stop tends to be more expensive than a failure to go!

 

[KevB]

My yachty neighbour in the marina likes to start up at least 20 mins before he leaves even in the early hours of the morning. Me being a stinkpot starts and leaves asap. I don't like the idea of smoking everyone out.

 

[Lakesailor]

If the Greek God's engine hasn't got oil flowing well in less than 30 minutes his engine is buggered.

Like Vyv cox says, oil is there straight away. In vehicle engines which rev over 3/4000rpm it's good to get the oil over 50°C before using the revs, but slow revving marine engines should be ready for load once they have settled down. If you have issues like being forgetful or having current to contend with a minute or two to make sure it's running well shouldn't be a problem.

Can't see the logic in letting them run for ages at tickover.

 

[sailorman]

There we were, pouring beer down our throats, and him, of Greek God fame, says something along the lines of (in an accent which is difficult enough to understand - especially if you have use Greek God's name as a username and you're a taffy) "I don't understand sailors that fire up their engines and move off within a few minutes. I warm mine up for at least 30 minutes before moving off".

"Well", says the Gringo on Stingo, in a knowing sort of way, "A diesel engine loves a load and if you're doing nothing more than idling, you'll clog up the art-cherries with muck and carbon and foot prints and and and...".

"Not so" says he, in a more knowingly Godly Greek manner. "You'll rip it to pieces in no time at all, because those pissed-ons and pissed -offs are not near enough lubricated; unlike you and I".

"Ah", says I. "Is this not an austerity measure to consume more diesel so that the plebeians have work"?

.... and so the conversation went around and around, in pointless revolutions per minute, warming up not only the environment, but also the discussion.

Please settle this for us, oh great diesel gurus; what should it be - a few minutes or a several litres of diesel burnt in warming up the en-wino-ment?

How do you operate a car / truck engine.
Start n go

 

[bedouin]

Probably something horribly wrong with my engine - but if I don't let it warm up for 5-10 mins from cold it won't go anywhere. Just doesn't respond to throttle - I don't know if that is anything to do with having a folding prop that must cause greater resistence when in the folded position.

 

[jwilson]

Boat - Yanmar diesel - start up, 10 seconds at 1200-1500 rpm, while you check water flow, then down to tickover and into gear and go. I'd regard a 30 minute tickover warmup as vandalism to the engine.

On a diesel car I try not to use full revs/throttle for the first mile, but about half revs takes you to 70mph. Interesting that on a cold morning the electronics on my Volvo diesel restricts power for about 4 seconds from start-up. You can pull away smoothly but not fast. Normal power definitely kicks in about 10 yards down the road.

 

[Deleted member 478]

Thank you for the very informative replies. Glad I am not going to have to learn a new habit.

 

[Twister_Ken]

Probably something horribly wrong with my engine - but if I don't let it warm up for 5-10 mins from cold it won't go anywhere. Just doesn't respond to throttle - I don't know if that is anything to do with having a folding prop that must cause greater resistence when in the folded position.

Bukh? If so, I had the same problem.


Modern Yanmar sets off like a tightly coiled spring.

 

[bedouin]

Bukh? If so, I had the same problem.


Modern Yanmar sets off like a tightly coiled spring.

Volvo MD2B - cold start is a lot less efficient (and a lot harder) than more modern units.

 

[GrahamM376]

Quote from Thornycroft T105 engine manual (Mitsubishi based)

WARMING UP Allow engine to warm up at low idle for 5-10 minutes. Proper warm-up is absolutely essential to maximum service life, performance and economy. NOTE. Long periods of warming up is not recommended, this can result in carbon deposits in the combustion chamber and incomplete fuel combustion.

STOPPING THE ENGINE. Allow to idle for 5 minutes to allow hot areas to cool gradually.

The above advice is the same as when I used to drive heavy plant equipment.

 

[Houleaux]

Probably something horribly wrong with my engine - but if I don't let it warm up for 5-10 mins from cold it won't go anywhere. Just doesn't respond to throttle - I don't know if that is anything to do with having a folding prop that must cause greater resistence when in the folded position.

My Volvo 2002 likes a few minutes to warm up - particularly when ambient temp v low.

I've reversed off my berth a bit too soon after starting and experienced a nail biting moment when putting into forward gear and waiting what seemed like an age for revs to rise above idle.

I think diesels need a few moments to wake up (don't we all!). I remember a Mondeo turbo diesel I had from new in the 90s. I started it and drove up a steep drive immediately. I was flat out and it only just made it without stalling. Would have been no problem at all when warm.

 

[Cardo]

STOPPING THE ENGINE. Allow to idle for 5 minutes to allow hot areas to cool gradually.

I find I always do this naturally as it's more or less the time it takes to ensure all lines, including springs are secure! Once boat is secure, turn off engine.

 

[Amulet]

My engine supplier says start up and go - with bore glazing being the threat otherwise. They do say to run it at moderate revs not flat out until it is up to temperature. They say that it is perfectly happy at constant max revs thereafter, which surprised me. But then, mine is just a jumped up cement-mixer engine - and if you do run it at max revs the noise will drive you insane and the vibration will loosen the keel bolts.

(I called them all the way to Germany about it and got a very friendly engineer.)

 

[fireball]

Preparing to take our (old) boat round to the mooring having just been launched I started the engine and left it on tickover.... 20 minutes later (whilst we finishing bending on sails) the engine stopped ...

So the change of fuel filter HAD introduced some air into the system and we needed to bleed it through ... glad I "warmed" the engine that time.

Don't normally though - prepare boat, start engine, test forward and reverse thrust (ensure the prop hasn't fallen off), cast off and go ...