Ive broken my Engine, ideas needed

[MtB]

And Gardner call them 'sprayers'...

[bargemast]

 

Back in the 1950's and 60's the term 'injector' was rarely', if ever, found in the repair/maintenance manuals of most diesel engine makers, . . . preferring instead to describe them as 'atomizers'.

 

Which shows that in the 50's and 60's they gave the name to make clear what the funtion of this part really was, I don't know why they commonly changed that name in later years, as there's no better name.

 

In Dutch they call them "verstuivers" which translate as "atomizers", so maybe the Dutch aren't as stupid as many think after all.

 

Peter.

[bargemast]

And Gardner call them 'sprayers'...

 

I see that Gardner gives them 2 names :"sprayers/injectors" on their site : http://www.gardnermarine.com/our-facilities/

 

Peter.

[Tony Dunkley]

 

I see that Gardner gives them 2 names :"sprayers/injectors" on their site : http://www.gardnermarine.com/our-facilities/

 

Peter.

 

I would think that the term 'sprayer' is a hark back to the times of hot bulb, or semi-diesels which operated on compression ratios too low for compression ignition when starting from cold. The device for introducing fuel into the combustion space was nothing more elaborate than a nozzle for 'spraying' fuel at relatively low pressure onto something hot, in this case either the 'hot bulb' in the head or the piston crown when hot enough, and not capable of 'atomizing' the fuel in the way that later 'injectors' were with spring loaded pintle valves vibrating open and closed at very high frequencies during injection and operating at pressures of up to 2000 psi, or more.

Gardners, with their endearing fondness for being old fashioned persisted in using the term 'sprayers', whilst other makers of semi-diesels, such as Petters, eventually began to call them 'atomizers' after they progressed to manufacturing true compression-ignition engines.

Edited April 2, 2016 by Tony Dunkley

[nicknorman]

If you inject "droplets of fuel" your injectors are shot, they should inject a very fine spray more like a mist to spontaneously ignite.

 

Peter.

A mist is comprised of droplets. Anyway the relevant point is that it is fuel mostly in the liquid phase, whereas with petrol it should all be in the vapour phase. Edited April 2, 2016 by nicknorman

[Loafer]

 

 

Lol, I expect that was what Tony decided not to tell you!

 

 

 

 

Me too.

 

First question, is what does 'retarded' mean, exactly? Is is injection after TDC? Or simply injection later than at the optimum angle?

 

I know what 'retarded' means. That's ME!

 

(Oh, thought you said RETIRED. Sorry...)

[dmr]

No, it's important to bear in mind that compression ignition occurring in a petrol engine is pretty instantaneous (and bad for it!) due to the fact that the whole cylinder is full of near-stochiometric mixture of fuel vapour and air. However in a diesel you inject droplets of fuel and so the compression ignition is a much slower process with each droplet burning from the outside in. So it's definitely a burn as opposed to a detonation.

 

That is what I was trying to say, but as is often the case you said it much better. This is why the diesel injection people constantly search for higher and higher injection pressures. Also for many years diesels were only used in low revving trucks etc and it was felt that the "high speed diesel" suitable for cars could not be done, a major reason for this was it was just not possible to get the combustion going fast enough.

 

Compression ignition in a petrol engine is "detonation" and can be very destructive. The old VW air cooled engines were a good example. The piston got too hot and fell apart, the con rod small end then dropped down and the rod shoulder then came right out right through the side of the crankcase.

 

...............Dave

[bargemast]

A mist is comprised of droplets. Anyway the relevant point is that it is fuel mostly in the liquid phase, whereas with petrol it should all be in the vapour phase.

 

Oké Nick, it's surely because of my lack of understanding the finer details of the English lauguage, but I've always understood that droplets were small drops.

 

Small drops (the ones I know) wouldn't be what a diesel engine would like to get served for breakfast, lunch or dinner.

 

Peter.

[nicknorman]

Oké Nick, it's surely because of my lack of understanding the finer details of the English lauguage, but I've always understood that droplets were small drops.

 

Small drops (the ones I know) wouldn't be what a diesel engine would like to get served for breakfast, lunch or dinner.

 

Peter.

I think our disagreement is only about semantics. Small drops are droplets. As far as I know there is no commonly used word for small droplets. If you type "define mist" into Google, the first hit talks about it being comprised of droplets. Thus a spray of liquid diesel from an injector is made up of droplets. Large droplets would be bad news, small droplets are what is desired.

[Loafer]

I think our disagreement is only about semantics. Small drops are droplets. As far as I know there is no commonly used word for small droplets. If you type "define mist" into Google, the first hit talks about it being comprised of droplets. Thus a spray of liquid diesel from an injector is made up of droplets. Large droplets would be bad news, small droplets are what is desired.

 

 

(Gazing in wonder)

[dmr]

I think our disagreement is only about semantics. Small drops are droplets. As far as I know there is no commonly used word for small droplets. If you type "define mist" into Google, the first hit talks about it being comprised of droplets. Thus a spray of liquid diesel from an injector is made up of droplets. Large droplets would be bad news, small droplets are what is desired.

 

Does your engine prefer droplets, mist, a fine spray, or even atomised fuel? This could be better than pumpout vs cassette.

 

...............Dave

[FadeToScarlet]

 

Does your engine prefer droplets, mist, a fine spray, or even atomised fuel? This could be better than pumpout vs cassette.

 

...............Dave

You need a semi diesel with an oil rod, then you can fiddle with changing the pattern as you go along.

[bargemast]

 

Does your engine prefer droplets, mist, a fine spray, or even atomised fuel? This could be better than pumpout vs cassette.

 

...............Dave

 

There's no substitute for a good compost toilet

 

Peter.

[Sir Nibble]

At 30,000 psi through a tiny hole fuel arrives in the appearance of a mist drifting in the air rather like smoke. This mist is however composed of microscopic "droplets" of liquid fuel.

[MtB]

At 30,000 psi through a tiny hole fuel arrives in the appearance of a mist drifting in the air rather like smoke. This mist is however composed of microscopic "droplets" of liquid fuel.

 

 

That's the sort of pressure a common rail diesel runs at IIRC. I've an idea ordinary modern diesel like Nick's would be about 10% of that. And the sprayer in a hot bulb semi diesel is probably only about 1%... but I don't actually know.

[bargemast]

At 30,000 psi through a tiny hole fuel arrives in the appearance of a mist drifting in the air rather like smoke. This mist is however composed of microscopic "droplets" of liquid fuel.

 

Thanks for your explanation Sir, my lack of understanding the finer meaning of certain words makes it more difficult to catch some subject at their right value.

 

Peter.

[smileypete]

Wonder if the 'goo' is polymerisation of part of the FAME component of modern diesel fuel.

 

Being temperature dependent it might be more likely to occur in the pump which gets some heat from the engine.

 

IF it is then strong alkali or certain solvents may shift it.

 

But OTOH it could even be a kind of soap (free fatty acids combined with an alkali), IF so then acid may be needed to shift it.

 

Has the engine spent long periods at idle for batt charging? I s'pose that would mean slower fuel flow and so longer heat exposure as the fuel goes though the injection pump.

 

A trawl of google on 'diesel gunk in injection pump' might turn up some useful info, maybe even some ideas and recommendations for fuel stabilisers.

Edited April 3, 2016 by smileypete

[Loafer]

Wonder if the 'goo' is polymerisation of part of the FAME component of modern diesel fuel.

 

Being temperature dependent it might be more likely to occur in the pump which gets some heat from the engine.

 

IF it is then strong alkali or certain solvents may shift it.

 

But OTOH it could even be a kind of soap (free fatty acids combined with an alkali), IF so then acid may be needed to shift it.

 

Has the engine spent long periods at idle for batt charging? I s'pose that would mean slower fuel flow and so longer heat exposure as the fuel goes though the injection pump.

 

A trawl of google on 'diesel gunk in injection pump' might turn up some useful info, maybe even some ideas and recommendations for fuel stabilisers.

 

Blimey Pete, I don't get yer banter old boy, but a greenie for being able to type it!

[dmr]

Wonder if the 'goo' is polymerisation of part of the FAME component of modern diesel fuel.

 

Being temperature dependent it might be more likely to occur in the pump which gets some heat from the engine.

 

IF it is then strong alkali or certain solvents may shift it.

 

But OTOH it could even be a kind of soap (free fatty acids combined with an alkali), IF so then acid may be needed to shift it.

 

Has the engine spent long periods at idle for batt charging? I s'pose that would mean slower fuel flow and so longer heat exposure as the fuel goes though the injection pump.

 

A trawl of google on 'diesel gunk in injection pump' might turn up some useful info, maybe even some ideas and recommendations for fuel stabilisers.

 

I have been thinking about this very hard, going over the history in my head, and scouring the www for clues and I think you are almost right.

The problem actually started a couple of months ago (I think) but the symptoms were very subtle. In January we left the boat for a week to go to Cornwall and unluckily this co-incided with a cold snap where the engine might have got down to -3 or less.

 

There was a spate of issues a couple of years back in the East and North East, probably related to a batch of fuel with a suspect FAME component. It waxed in the cold but when heated up again the wax remained as wax. The Stanadyne man said he had never seen anything quite like it before but it looked more like wax than diesel bug. I am just surprised nobody else has experienced anything similar.

 

If you are right about heat rather than cold then we do do a lot of battery charging in winter, but I try to keep the revs highish, but its still a lot less fuel flow than cruising.

 

...............Dave

Edited April 3, 2016 by dmr

[smileypete]

Maybe a batch that was poorly processed or stored or contaminated.

 

Bigger risk of coming across if ccing throughout winter with lower fuel turnover at marinas I s'pose . A google search on 'diesel fame polymerisation' will turn up a load of stuff on it.

 

Seems that normal biodiesel has a relatively short shelf life and needs antioxidant stabilisers to stop it polymerising in the longer term:

 

http://www.chemiphase.co.uk/biodieselantioxidants/

 

Normal wax will dissolve/melt, just needs some heat. Polymerisation is 'cross linking' like oil paint does, so is more permanent. A spill of sunflower oil will go sticky and eventually almost like a plastic if left long enough.

Edited April 3, 2016 by smileypete

[dmr]

Maybe a batch that was poorly processed or stored or contaminated.

 

Bigger risk of coming across if ccing throughout winter with lower fuel turnover at marinas I s'pose . A google search on 'diesel fame polymerisation' will turn up a load of stuff on it.

 

Seems that normal biodiesel has a relatively short shelf life and needs antioxidant stabilisers to stop it polymerising in the longer term:

 

http://www.chemiphase.co.uk/biodieselantioxidants/

 

Normal wax will dissolve/melt, just needs some heat. Polymerisation is 'cross linking' like oil paint does, so is more permanent. A spill of sunflower oil will go sticky and eventually almost like a plastic if left long enough.

 

That additive is mostly for storage, but all of the standard additives do contain some stabilisers. I have mostly used Stanadyne performance formula but recently switched to Morris Morendo. I am not at all sure about Fuel Set as that also contains an emulsifier and I suspect that de-emulsifiers are better. Interestedly there was a period of several months in the summer when I used no additive.

 

Thinking more, the Stanadyne pump has a lot of leak off so even at slow battery charging speeds we are still shifting more fuel than many engines would when cruising. However a badly controlled batch of fuel could cause all sorts of trouble and I do suspect that the bio part is more random than the proper part.

 

Another issue is that we are told to keep our tanks full to minimise moisture but constant topping up does mean that some of the fuel in the tank will be very old. I expect that at least a few molecules date right back to when the boat was built in 2001. Running down to empty then a full fill would keep the fuel fresher.

 

I try to get my fuel from the cheapest suppliers as these usually have the fastest turnover. Winter fuel on the K&A is actually good. We now have a pair of diesel boats who sell a lot of fuel (lots of semi static boats are good customers). They do a run once per month, take on 4500 litres (I think) and sell the whole lot over the next three days.

 

My fuel system is such that the injector pump is one of the lowest points in the system so there might be more potential for stuff to linger there.

 

I am pretty much convinced this issue was either non reversible waxing or polymerisation but not sure how to find out which.

I've got a bit of the bad stuff here so could do a few tests, but have promised to give most of it to a man who makes fuel additives.

 

.................Dave

Edited April 4, 2016 by dmr

[Laurie Booth]

 

Retarded is just the opposite of advanced.

To retard the timing means to make it later in the cycle.

Retarded would also mean later than optimum in most cases.

Just like in petrols these things never happen exactly at TDC because there are all sorts of delays and typically you need combustion quite well established by TDC so that most of it happens just after TDC, hence things must start a little before TDC. Its not as bad as it sounds because near to TDC there is very little "torque arm" so not a big torque to try to push the engine backwards.

mind, my old VW bus would sometimes crank very very slowly and when it did do a good combustion it would stop the engine dead.

 

As you go faster the delay can reduce a little bit (in terms of milliseconds), but still represents an increasing crank angle so it is generally required to advance the timing as speed increases.

 

............Dave

Advance and retard ignition lever on my 1932 Austin 7

[dmr]

Advance and retard ignition lever on my 1932 Austin 7

 

A thing of the past.

Most modern/younger drivers do not even know what a choke is so how would they cope with one of those? Also I suspect they would be banned now as they are not politically correct.

 

................Dave

[peterboat]

 

I have been thinking about this very hard, going over the history in my head, and scouring the www for clues and I think you are almost right.

The problem actually started a couple of months ago (I think) but the symptoms were very subtle. In January we left the boat for a week to go to Cornwall and unluckily this co-incided with a cold snap where the engine might have got down to -3 or less.

 

There was a spate of issues a couple of years back in the East and North East, probably related to a batch of fuel with a suspect FAME component. It waxed in the cold but when heated up again the wax remained as wax. The Stanadyne man said he had never seen anything quite like it before but it looked more like wax than diesel bug. I am just surprised nobody else has experienced anything similar.

 

If you are right about heat rather than cold then we do do a lot of battery charging in winter, but I try to keep the revs highish, but its still a lot less fuel flow than cruising.

 

...............Dave

I have seen it Dave who runs a waste transfer station had a dose of it (about 10 thousand litres) you could see it form wax as it got cold when it warmed up most of the wax went but a little remained. It was from a failed batch of bio diesel. Dave used it in the heating system in the garage for which it worked well. For him it was a win win situation

[dmr]

I think one problem here is that there is no co-ordinated reporting of problems so we each have our own bad experience but don't know if its an isolated failure or a common problem. I suspect the fuel wholesalers are going to be quite secretive here. However RCR do provide some statistics on what is going on. I note that they used to replace 2 injection pumps each year but in 2014 replaced 48, though they do infer that this was from water damage.

Luckily my pump sustained no damage or wear, just contamination.

If this starts happening on a regular basis I will be seriously unhappy.

Its tempting to drain the tank but its a lot of fuel to throw away, and whatever I replace it with might be just as bad.

Instead I am going to spend more money to get my old spare pump inspected and tested so that I can carry a spare.

 

Another thing I have learned from all of this is that sometimes the bio part of the diesel is made from dead animals. This is not good because our boat is a vegetarian.

 

..............Dave