Wiggo
New member
AFAIK...
Ooops. KAMD43P pistons shouldn't look like this
- Thread starter Wiggo
- Start date
Bazzer
Member
Oh dear 
A_8
Active member
What happened?
Wiggo
New member
Don't know yet, sadly. That's number 2 piston, and it's melted...
A_8
Active member
I am no expert but it looks like its been hitting the valves. What were the symptoms?
Latestarter1
New member
Injector nozzle spray pattern damaged by water/debris.
Wiggo
New member
Excessive oil consumption while out on charter, then a sudden loss of power. Other than that, nothing. Still waiting for more news.
burgundyben
Well-known member
Is that rusty colour fluid spilt coolant?
No Regrets
Active member
Looks like a valve has imbedded itself into the piston crown...
Latestarter1
New member
Those are the valve clearance cut outs machined into piston. Of note are two critical features features of abnormal combustion caused by malfunctioning injector.
#1 Typically gnawed off edge of piston crown.
#2 Moonscape effect on less damaged part of the crown with start of combustion gnawing on this edge.
#3 No damage whatsoever in combustion chamber.
Typical of not fit for purpose fuel filtration.
Unless fuel filtration system gets the once over, always the potential for repeat failure.
A_8
Active member
Wiggo, what fuel filtration set up do you have?
volvopaul
Well-known member
o
I'm the engineer on this one LS
Boat has Racor FG500 with volvos label on it and standard single filter which you may know as Baldwin BF988.
Engin started and ran fine but filler cap did low orbit test as you like to describe. Head off yesterday afternoon( yes I do sometime work Sunday's) boats moored two up from mine so no excuse for being late !!.
Let's wait and see what pump shop says about nozzles and Bosch pump.
This set up is standard throughout most pleasure boats, so why will it not work , water should stay in Racor bowl so what do you suggest as not only do fuel pump and injection problems cost but this is the result of this failure which will now cost.
Today I took call from Atlantic 42 owner with 63p motors saying his boats stopped and his pre filters are full of diesel bug jelly, he asked what to treat it, I suggested he have his tanks cleaned but access is non existent without extensive internal furniture removal, he spoke to tank cleaning co who said treat it with suitable chemical and go out and burn what's in the tank, he didn't even think that the engines fine filters would need changing.
Personally I'd want to dump the whole tanks contents, clean out every pipe and filter housing, test injectors a must before it's too late and his Pistons look like wiggos number 2.
I do wonder if these tank cleaning companies know about the results as I've seen so many boats just breed the bug straight after a clean, to me there is more to this bug than we really know, so what do we use?
Soltron, marine 16 etc? Anyone had the bug and had a happy outcome from a pure treatment without a full tank clean?
What filter set up would you suggest will be the minimum requirement LS and a standard pleasure boat?
Latestarter1
New member
Hi Paul,
Yes I know I have banged on in the past regarding the agglomeration capacity of Racor FG500 and my views on two stage filtration are at odds with what production builders offer.
Going back to Wiggo's #2 piston. Yes I can visualise the failure mode, the abnormal combustion takes its toll of the top ring crevice first as there is only limited cooling and hot exhaust gases sit in the crevice, the Moonscape pattern on the crown is supporting evidence, caused by fuel droplets from incomplete atomisation. The piston cooling by oil jet cools the combustion chamber by way of the cocktail shaker in the piston gallery however the area outside the combustion chamber starts to burn progressively.
Good news if there is any for Wiggo is that this is not an engine durability issue.
My pump shop now has a brilliant piece of kit for analysis of injector spray patterns, injects test fluid into a gel which has the effect of a time lapse camera. I am currently investigating a failed D6 in Australia with lots of injector argy bargy.
Good luck
Yes I know I have banged on in the past regarding the agglomeration capacity of Racor FG500 and my views on two stage filtration are at odds with what production builders offer.
Going back to Wiggo's #2 piston. Yes I can visualise the failure mode, the abnormal combustion takes its toll of the top ring crevice first as there is only limited cooling and hot exhaust gases sit in the crevice, the Moonscape pattern on the crown is supporting evidence, caused by fuel droplets from incomplete atomisation. The piston cooling by oil jet cools the combustion chamber by way of the cocktail shaker in the piston gallery however the area outside the combustion chamber starts to burn progressively.
Good news if there is any for Wiggo is that this is not an engine durability issue.
My pump shop now has a brilliant piece of kit for analysis of injector spray patterns, injects test fluid into a gel which has the effect of a time lapse camera. I am currently investigating a failed D6 in Australia with lots of injector argy bargy.
Good luck
Wiggo
New member
Hmm. So some history on these engines.
Bought the boat back in 2004 (from memory) with a fresh full engine service by RK Marine. Once warmed up, the port engine annoyingly ticked over at about 800-850 rpm vs 600 or so for the other. Turned down the idle speed and the engine would stall if it was warm. Col did some investigation and it had two knackered injectors, with the internals completely disintegrated (Bosch said they had never seen anything like it). Vague rumour of a previous owner putting water in the fuel tank by mistake, but nothing confirmed. 12 months later, huge clouds of black smoke on a run back from Weymouth and a major loss of power from the port engine. Four dead injectors on this occasion. Another two failures on the same lump subsequently, and the diesel pump was replaced a few years ago as well. A proper Friday afternoon engine. Never a problem with the starboard one.
Anyway, no water in the separators that I can remember, though we did suffer from swarf blocking the pickup pipes (the old Sealine plastic tank problem, fixed in the end). Had a bit of a problem with bug about 8/9 years ago, and I used to dose with Soltron when I could find the stuff, but no real trace of bug in years.
If a failed injector can cause this sort of failure, I'd be fascinated to see the state of the pistons on the port engine, as that has eaten its way through at least 8 injectors and a pump, and always been 'lazy', never feeling like it was pulling its weight.
Bought the boat back in 2004 (from memory) with a fresh full engine service by RK Marine. Once warmed up, the port engine annoyingly ticked over at about 800-850 rpm vs 600 or so for the other. Turned down the idle speed and the engine would stall if it was warm. Col did some investigation and it had two knackered injectors, with the internals completely disintegrated (Bosch said they had never seen anything like it). Vague rumour of a previous owner putting water in the fuel tank by mistake, but nothing confirmed. 12 months later, huge clouds of black smoke on a run back from Weymouth and a major loss of power from the port engine. Four dead injectors on this occasion. Another two failures on the same lump subsequently, and the diesel pump was replaced a few years ago as well. A proper Friday afternoon engine. Never a problem with the starboard one.
Anyway, no water in the separators that I can remember, though we did suffer from swarf blocking the pickup pipes (the old Sealine plastic tank problem, fixed in the end). Had a bit of a problem with bug about 8/9 years ago, and I used to dose with Soltron when I could find the stuff, but no real trace of bug in years.
If a failed injector can cause this sort of failure, I'd be fascinated to see the state of the pistons on the port engine, as that has eaten its way through at least 8 injectors and a pump, and always been 'lazy', never feeling like it was pulling its weight.
Latestarter1
New member
Paul,
From comments made by Wiggo seems like vessel has been a slightly troubled child.
Despite what the data sheet says I would never use FG500 in front of engine with potential for developing more than 100 hp, however that is a personal view and my mail box was swamped last time I said it.
Let me try some lateral thought. Is there enough room on the engine to upgrade the BF988 with BF1221? This change would improve 'last chance' potential of on engine filtration.
How about we consider a remote filter head and make the FG500 part of a two stage system and improve agglomeration properties upstream of last chance filter?
These mods would improve the system without embarking on expensive upgrades.
Good luck.
burgundyben
Well-known member
Fuel filtration deserves a thread on its own. Afterall many of us have expensive machinery to protect.
I wonder what it is specifically about water that makes it cause damage, is it the speed of the transition from liquid to gas?
Wiggo
New member
While the discussion on filtration is interesting, I do have a couple of pertinent questions:
As the setup on this boat is identical to thousands of other similar boats from many, many builders, why do we not see shredded injectors and burnt pistons all over the place?
If an injector gets water in the internals, I understand it is likely to cause damage to the plungers, springs etc and that in turn will cause it to hose rather than spray. Common sense says that will cause poor and/or incomplete combustion in that cylinder. Why does this lead to burning and damage to the piston? Again, common sense says that damage would be caused by excessive temperatures, not partial combustion.
As the setup on this boat is identical to thousands of other similar boats from many, many builders, why do we not see shredded injectors and burnt pistons all over the place?
If an injector gets water in the internals, I understand it is likely to cause damage to the plungers, springs etc and that in turn will cause it to hose rather than spray. Common sense says that will cause poor and/or incomplete combustion in that cylinder. Why does this lead to burning and damage to the piston? Again, common sense says that damage would be caused by excessive temperatures, not partial combustion.
tinkicker0
New member
LS is absolutely correct, you are looking at fuel erosion. I lost count of the number of times I have seen this. Certainly in the 100s.
Bad injectors have many effects on combustion and most of them increasing the temps on the piston crown and in the cylinder.
1. Physical erosion caused by droplets smacking the top of the piston and wearing it away.
2. Burning of the piston crown caused by these droplets breaking through the thin, protecting boundary layer of gas on the piston crown and igniting directly on the alloy at temps far higher than the alloys melting point.
3. Excessive ignition delay due to the size of fuel droplets which causes higher temps for longer periods due to uncontrolled combustion. Personally I would be tempted to change the exhaust valves while the head is off because of this. They will have been very unhappy.
4. Mechanical damage due to broken away particles rattling up and down in the cylinder.
Other things to check are that the exhaust ports/manifold have not collected an acretion of alloy inside that can break off in large lumps and go into the turbo hot section and also that the turbine wheel has not already suffered due to FOD.
Bad injectors have many effects on combustion and most of them increasing the temps on the piston crown and in the cylinder.
1. Physical erosion caused by droplets smacking the top of the piston and wearing it away.
2. Burning of the piston crown caused by these droplets breaking through the thin, protecting boundary layer of gas on the piston crown and igniting directly on the alloy at temps far higher than the alloys melting point.
3. Excessive ignition delay due to the size of fuel droplets which causes higher temps for longer periods due to uncontrolled combustion. Personally I would be tempted to change the exhaust valves while the head is off because of this. They will have been very unhappy.
4. Mechanical damage due to broken away particles rattling up and down in the cylinder.
Other things to check are that the exhaust ports/manifold have not collected an acretion of alloy inside that can break off in large lumps and go into the turbo hot section and also that the turbine wheel has not already suffered due to FOD.
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Wiggo
New member
Volvopaul will confirm, I'm sure, but I believe the rebuild kit includes pistons, liners and valves. At the price, I'd expect them to be gold plated.
burgundyben
Well-known member
Interesting paper here. Suggests that ULSD is more difficult to cleanse of emulsified water.
http://donaldsonoemfiltration.com/library/files/documents/pdfs/053491.pdf
http://donaldsonoemfiltration.com/library/files/documents/pdfs/053491.pdf
Other threads that may be of interest
