A_8
Active member
Very interesting, makes one wonder how many engines have this slowly growing in their bellies with owners skipping injector checks or replacements.
Ooops. KAMD43P pistons shouldn't look like this
- Thread starter Wiggo
- Start date
Very interesting, makes one wonder how many engines have this slowly growing in their bellies with owners skipping injector checks or replacements.
burgundyben
Well-known member
These engines have done 1500 hours, if that was a commercial application working 12 hours a day, 5 days a week, so a fairly light duty cycle for commerce, the engine would be like this in 25 weeks. Leisure application low duty cycle masking the problem?
julians
Well-known member
What checks can an owner actually do? Is it a diy job to check the injectors are functioning correctly, or is it a specialist task?
Until this thread I wasn't aware of the need to check them.
KevB
Active member
ok, slightly worried here. I have the KAD version of these engines with 1200 hours. I've never had the bug and never an issue with water in the separators, so at what age/time should injectors be checked? Engines run as smooth as ever.
thanks
thanks
Questor
Active member
Likewise. Graham makes reference to a previous owner putting water into the diesel tank, although unconfirmed.
However, I remember some years ago on here, there being concern over biodiesel being added to marine diesel, which can absorb water, and that there could be trouble ahead. Could this be the start?
Premier, from whom I usually buy diesel, say that no bio content is in their diesel. I wonder if this is the case for other outlets?
Likewise I've had no issues with water in the separators.
Of course, I could be barking completely up the wrong tree, but am following this thread with interest.
Portofino
Well-known member
The service manual usually says when its time to pull the injectors -inspect/re-furb -replace etc .
with MAN and I think MTU its 1000 hours ,
When I was in the MKT for a new boat over the winter I noticed those over a 1000 hrs would have had this "biggi " service done .
those that had not it done -after enquires I closed down my interest .
From memory I can,t remember Volvo,s
To mitigate from water etc in the fuel with my KAD 300 (Sunseeker ) I always put in a fuel additive Star tron - throughout the 9 years of ownership .
Currently continuing with the MAN powered ITAMA .
This stuff reckons to disperse any water for a better spray pattern + burn etc
Remember condensation is another source of water from the inside of a metal tank -part filled -not just a duff batch picked up at a doggy refuel ?
In the global £££ of running -this "hobby " adds up to peanuts
this 1000 hr " Biggi " is also a valve clearance ck too as well as pulling the injectors
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burgundyben
Well-known member
Trundlebug
Active member
I can't imagine there weren't some early symptoms of poor injector performance / hosing, like black smoke, before failure.
The poor combustion would definitely show itself through smoke, although I guess if the exhausts exit underwater it would be harder to detect.
In any even the failure wouldn't by any means have been instant - diesels are robust pieces of kit and do generally give early warning of impending doom.
The poor combustion would definitely show itself through smoke, although I guess if the exhausts exit underwater it would be harder to detect.
In any even the failure wouldn't by any means have been instant - diesels are robust pieces of kit and do generally give early warning of impending doom.
Portofino
Well-known member
Dunno -without the label in front of me -words to that effect .
There are other marine diesel additive products on the mkt that reckon / claim ------- deal with the water in the fuel ,in such a way to not compromise the atomisation of the fuel at the injector tip -
and yes may all be snake oil
A_8
Active member
Its a specialist job, there are companies just checking and refurbishing injectors and with 2 6cyl engines quite expensive hence my comment, many owners don't want to take the cost.
A_8
Active member
I think the KAD engines have their check intervals at 6-800h.
Wiggo
New member
Nothing I was aware of. The port engine was playing up - a bit of smoke, not making full revs - so a service was due, but the starboard lump had never missed a beat until now. I'd taken her out once before the day she blew up, with no problems, and before that she'd done a week's charter with a sea school, so all low speed pootling.
Apart from the unconfirmed report of water in the port tank many years ago, I've never seen any significant water in the separators, either, and the tanks are a) plastic and don't suffer from condensation like steel tanks, and b) left full over the winter.
lynall
Active member
Over the years Ive seen many truck engines in bits, none like the ops pics, some way more expensive mind!
I have inspected and serviced thousands of trucks and none have ever had injectors replaced as part of regular servicing., when they cause an issue they are changed but not before.
Where I now work many of the trucks are coming up to 1 million kilometres and none have ever had the heads off ever.
I often also see sludge in the water seperators so the diesel is not as clean as it should be either.
Oil and all filters changed every 45k, not sure what that works out to in hours?
I have inspected and serviced thousands of trucks and none have ever had injectors replaced as part of regular servicing., when they cause an issue they are changed but not before.
Where I now work many of the trucks are coming up to 1 million kilometres and none have ever had the heads off ever.
I often also see sludge in the water seperators so the diesel is not as clean as it should be either.
Oil and all filters changed every 45k, not sure what that works out to in hours?
KevB
Active member
Hi Richard,
I always fill up in Chichester and this is what they say they supply in all their marina's except Falmouth...
"WP Marine's Advanced Marine Diesel 10 is a low sulphur fuel containing 10ppm (parts per million) sulphur. This high quality fuel is recognised as FAME FREE and is guaranteed by Esso to contain less than 1% bio element.
Advanced Marine Diesel 10 also contains Soltron®. Specifically developed to work with marine diesel at a dilution rate 10,000:1, Soltron® contains a blend of 20 naturally occurring enzymes which combine inside the fuel tank to optimise the combustion process and enhance fuel efficiency. Soltron® also provides lubrication in low sulphur marine fuel oil and neutralises bacterial growth from contaminants.
Based at Esso's Fawley Refinery near Southampton, WP Group is the South's leading independent supplier of fuels and lubricants, marketing Esso fuel and Mobil lubricants across a wide portfolio of business sectors and industries. Boat owners travelling abroad should be aware that this fuel may not comply with legislation outside the UK and customers should seek advice from their destination marina before travelling."
So probably the best marine fuel you can buy.
STEVEDUNSTABLE
Active member
Hi TK...long time no hear etc etc....... please forgive this stupid question, but my one cell brain is not keeping up here !!!!...you say that the fuel doesn't burn correctly be cause of the droplet sizes and is also "delayed".. so am I right in assuming that it doesn't burn all at "the same time"...if that is the case, how can less fuel burning give off more heat than all the fuel burning at the same time ??.....(yes this IS a genuine question) as I don't understand ...yet !!!
A_8
Active member
Perhaps the difference between trucks and boats engines has to do with the duty cycle, a boat engine is typically running at constant high power output levels ( no heat relief for hours) while a truck engine has a much more varied power cycle?
Heckler
Active member
Id like to see that piston with the carbon cleaned off. There is quite a bit where the vakves have been bouncing. Are you sure the piston has been nibbled?AFAIK...
S
superheat6k
Well-known member
Steve
It is simple to confuse heat energy with temperature - they are not the same thing. If the fuel is properly atomised (that is tiny tiny particles) each particle will have a high relative surface area. It burns by spontaneous combustion from the compression stroke heating the air charge above the ignition point of the fuel - the heat energy is released evenly throughout the charge within the combustion chamber. Now the high surface area to mass ratio of the particle means burning of each and every particle is swift and even. This causes a massive heating and expansion of the surrounding gas, and hence the power to drive the piston downward on its power stroke. But the temperature is not excessive in any specific places.
Now if the injector does not atomise properly instead of a minute particle you have relatively large droplets. Two things then happen. The fuel droplet itself does not reach the ignition temperature throughout its mass (this is happening very fast - at 2,400 RPM 20 times each second), so the burning only happens at the surface of the droplet, the colder centre of the droplet forms smoke and soot.
The second thing is the momentum of the relatively large droplet will hit the surrounding metal surfaces, and as already mentioned this penetrates the gaseous film layer protecting the piston surface material. As the power stroke proceeds the droplet can literally explode, causing an immense local temperature in the wrong place, and the explosion is followed by an implosion, whilst in direct contact with the delicate metal piston crown surface, which has an effect very similar to cavitation burn on a propellor blade.
It is not just poor quality fuel, but also incorrect point of injection (timing), or individual fuel pump elements not pumping evenly or incorrect / inaccurate synchronisation that can contribute to poor injection too. If the fuel is injected too early it can condense against the piston crown prior to reaching ignition point, if too late it does not have time to burn completely. If one cylinder receives the wrong volume of fuel this can also corrupt the burn process.
This is why attention to fuel injection equipment is best left to the experts with full test facilities. I regard an injector pull and test as a 5 yearly item on the VPs I have owned.
oldgit
Well-known member
GRQ.
Anybody fancy getting rich quick.?
Have got this fantastic idea.We will need a few bottles and some "magic" fluid to go inside.
.The actual make up of the liquid will of course need to be a state secret but this can only add to the sales teams hyperbole.The manufacturing can probably be done in my garden shed but the sales team will almost certainly need a floor or two in the Shard or similar.
Head Office will need to be in BVI or Jersey for obvious reasons.
We need to market this at anybody with overstressed stressed diesel engines who think that a £25.00 quid 5 oz bottle of clear liquid is going to fix any problems caused by not spending 10K on some proper servicing.
Cannot imagine why somebody has not already thought of this.
Ps.any suggestions for the best colour for this snake oil.
Anybody fancy getting rich quick.?
Have got this fantastic idea.We will need a few bottles and some "magic" fluid to go inside.
.The actual make up of the liquid will of course need to be a state secret but this can only add to the sales teams hyperbole.The manufacturing can probably be done in my garden shed but the sales team will almost certainly need a floor or two in the Shard or similar.
Head Office will need to be in BVI or Jersey for obvious reasons.
We need to market this at anybody with overstressed stressed diesel engines who think that a £25.00 quid 5 oz bottle of clear liquid is going to fix any problems caused by not spending 10K on some proper servicing.
Cannot imagine why somebody has not already thought of this.
Ps.any suggestions for the best colour for this snake oil.
Last edited:
gwommit
Member
Re: GRQ.
Looks like it happened after a Friday night out
Pi$$ed & Broke:very_drunk:
Looks like it happened after a Friday night out
Pi$$ed & Broke:very_drunk:
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