BMC 1.5 smoking at higher revs

[Tracy D'arth]

1 hour ago, StephenA said:

 

Again you make assumptions about things you do not know about - toothed belt from a major manufacturer, pulley and belt cleaned.

 

As for drop in replacements for the BMC 1.5 - there are other alternatives which drop in. And when our BMC wears out it's not the cost of spares - it's the fact that its reached the end of its rebuild cycle.

Canaline engines are a drop in replacement for 1.5D with packers and 1.8D straight in.

As usual TNLI you are talking absolute rowlocks. Please give it up before someone innocent believes your twaddle.

[TNLI]

6 hours ago, StephenA said:

 

Again you make assumptions about things you do not know about - toothed belt from a major manufacturer, pulley and belt cleaned.

 

As for drop in replacements for the BMC 1.5 - there are other alternatives which drop in. And when our BMC wears out it's not the cost of spares - it's the fact that its reached the end of its rebuild cycle.

Yes they do make a real difference. The belt on my engine is a GATES AUTO MASTER part number 6220MC, which is a toothed belt. If you have a smooth belt try changing it to that belt or its Continental equivalent, as there is no way it will slip unless something is wrong with the alternator or circulating pump etc.

 

There is no such thing as a rebuild cycle, the only reason why an old classic built donkey needs to be scrapped is if the operator does not get the crank inspected and polished up by a specialist company as I plan to do, and the crank fails, or lack of spare parts. The only spare I can't seem to find is a new torsional vibration damper bearing. Not even seen any used ones listed so far. There are companies that can make one to order, BUT they seem to be charging over a grand for that job. I suppose general corrosion of the block resulting from a failure to change the coolant might become a very long term issue, but no one has said anything about that type of internal corrosion causing a terminal problem. The external corrosion rate seems very low in comparison to the Yanmar in my first Yacht, as all the engine mounts and mixing elbow corroded very badly and the salt pump had to be binned due to the screws in the back rusting out.

 

In addition to the Beta Greenline 38 fitting the mounts, there is a new Chinese made copy, (CANALINE), I looked at, but it's not been in production for long enough to be a sensible choice. It only costs about 5 grand, but you always get what you pay for. It only has a 3 year warranty, the Beta has a 6 year one and they don't seem to have a keel cooling option, whereas Beta do, so if I did go mental and decide to sell my donkey because the dreaded torsional damper bearing is kaput, I would fit a new Greenline 38, OR if I decided that the power reduction was acceptable, a fully reconditioned Bukh 24 from Marine Enterprises Ltd.

Edited January 24, 2022 by TNLI

[TNLI]

16 hours ago, Tony Brooks said:

 

I doubt the stat would make much difference to the oil temperature. The oil gets its heat from the underside of the pistons and to a lesser extent the cylinder walls, with even less coming from bearing friction. I have long thought that many canal boat engines rarely get their oil as hot as the designer expected despite the fact they have no cold wind blowing around the sump.

 

FWIW. Perkins used to insist their 4-10X  engines had to be equipped with engine oil coolers, this was fitted onto the end of the heat exchange. The upshot was, on the Thames, we were dong an unsustainable number of oil changes to stop the oil changing to black grease. This all stopped when we disconnected the oil coolers. We even found the same in a boat brought down from the Broads when we got it.

 

Odd that Perkins would insist on an oil cooler. The thing I can't understand about canal boat owners is why they fit engines that are just too large, as using less than 1500 RPM is going to result in long term trouble. The only solution I can think of apart from Italian tune ups at a dock or marina, is to fit a 2 blade rather than the more common 3 bladed prop. That should help a bit, although I would still do an Italian tune up for 30 mins every 10 hours, like wot I did on some fishing boats that were trolling rather than trawling. Big waste of fuel fitting too big an engine.

[Tony Brooks]

6 hours ago, TNLI said:

Odd that Perkins would insist on an oil cooler. The thing I can't understand about canal boat owners is why they fit engines that are just too large, as using less than 1500 RPM is going to result in long term trouble. The only solution I can think of apart from Italian tune ups at a dock or marina, is to fit a 2 blade rather than the more common 3 bladed prop. That should help a bit, although I would still do an Italian tune up for 30 mins every 10 hours, like wot I did on some fishing boats that were trolling rather than trawling. Big waste of fuel fitting too big an engine.

 

And yet across the whole range of engine designs and sizes the fuel consumption of canal boats stay within the 1 to 2 liters per hour with most clustered around the 1.5LPH. Whatever the size of engine the power required too push a canal boat through the water is pretty much the same for a given boat on a given waterway so however large the engine, within reason, it will burn a similar amount of fuel to produce that power. As canal engine speed is so low (even on a BMC1.5) the higher speed advantage the direct injection diesel has, consumption wise,  is not significant. We are only talking about the difference operating an engine closer or further away from it most efficient speed makes.

 

Experience does not bear out either of your points as long as the prop size is correct, undersize is typically not  a problem but badly oversize that causes overloading may well cause long term problems if the boater insists in running it at overloading speed.

 

Also remember that with 175 Amp domestic alternators and 40 Amp engine ones probably demand more than 10hp at full output, that is on top of power needed to propel the boat. It is far from unknown for an engine fitted with a large alternator to refuse to rev up at first start because it can't produce the power required to accelerate the alternator and boat. On other boats the drive belts tend to slip at first start up of the day, illustrating the power alternators require. Then there are the power requirements when Travelpsowers are fitted (240VAC alternators).

 

Neither point has much significance for an inland boater.

[TNLI]

35 minutes ago, Tony Brooks said:

 

And yet across the whole range of engine designs and sizes the fuel consumption of canal boats stay within the 1 to 2 liters per hour with most clustered around the 1.5LPH. Whatever the size of engine the power required too push a canal boat through the water is pretty much the same for a given boat on a given waterway so however large the engine, within reason, it will burn a similar amount of fuel to produce that power. As canal engine speed is so low (even on a BMC1.5) the higher speed advantage the direct injection diesel has, consumption wise,  is not significant. We are only talking about the difference operating an engine closer or further away from it most efficient speed makes.

 

Experience does not bear out either of your points as long as the prop size is correct, undersize is typically not  a problem but badly oversize that causes overloading may well cause long term problems if the boater insists in running it at overloading speed.

 

Also remember that with 175 Amp domestic alternators and 40 Amp engine ones probably demand more than 10hp at full output, that is on top of power needed to propel the boat. It is far from unknown for an engine fitted with a large alternator to refuse to rev up at first start because it can't produce the power required to accelerate the alternator and boat. On other boats the drive belts tend to slip at first start up of the day, illustrating the power alternators require. Then there are the power requirements when Travelpsowers are fitted (240VAC alternators).

 

Neither point has much significance for an inland boater.

Don't understand why you still post about the large AC alternator conversion idea when I did say that having looked at the pulley required it's a no go. Also the fact that no one else seems to be fitting this type of alternator is another negative. 

 

Fitting an oversize prop would only be an issue if you did it on a canal boat that was then moved to an area where you can use full chat. Even if you did that your engine will warn you by that it is being overloaded by producing black smoke,

 

In reality the Italian tune up is a far better method of reducing the harm done by low power use, although the Carbon deposits that result also get into the oil and can even effect the spray pattern of the injectors. The solution is to use a major brand oil with lots of detergents, (High TBN in the data sheet), a pre oil change idle only flush additive once a year, and diesel purge, which is a injection system cleaner used at idle not a fuel additive, and it will clean any baked on deposits or varnish forming in the injectors due to low power use. 

  I would note that some experts have said that it takes many hour, (One quoted 10), at near max continuous RPM to clean the Carbon deposits out of a fouled up diesel, which is why folks used to do a decoke in the old days. 

 

Edited January 24, 2022 by TNLI

[Tony Brooks]

15 minutes ago, TNLI said:

Don't understand why you still post about the large AC alternator conversion idea when I did say that having looked at the pulley required it's a no go. Also the fact that no one else seems to be fitting this type of alternator is another negative. 

 

Fitting an oversize prop would only be an issue if you did it on a canal boat that was then moved to an area where you can use full chat. Even if you did that your engine will warn you by that it is being overloaded by producing black smoke,

 

In reality the Italian tune up is a far better method of reducing the harm done by low power use, although the Carbon deposits that result also get into the oil and can even effect the spray pattern of the injectors. The solution is to use a major brand oil with lots of detergents, (High TBN in the data sheet), a pre oil change idle only flush additive once a year, and diesel purge, which is a injection system cleaner used at idle not a fuel additive, and it will clean any baked on deposits or varnish forming in the injectors due to low power use. 

  I would note that some experts have said that it takes many hour, (One quoted 10), at near max continuous RPM to clean the Carbon deposits out of a fouled up diesel, which is why folks used to do a decoke in the old days. 

 

 

This forum is not here for your specific needs, many others read it and ask advice. The fact that you may have discounted the idea of driving an AC generator off a drive belt does not mean that it is not fitted to any other bats so when thinking about engine power all the loads on engines need taking into account  and in some cases that includes a Travelpower. As an example 2000 Watts output requires 2000/749 to get hp and that equals just over 2.5hp assuming 100% efficiency, but it won't be 100% efficient so even if its 50% efficient (which I doubt) you are still looking at an extra 5 hp plus the load from any other alternators.

 

Real life experience simply does not support your assertions. We don't need frequent de-cokes, We don't suffer much from excess carbon build up, injectors seem to still be producing an acceptable spray pattern (judging by engine smoke and starting) after 10 to 20 years or more.

 

This experience includes hire fleets who deliberately under prop their boats to ensure the customers maintain reasonable charging revs and others who over prop to give better stopping power. The problem you perceive are simply not an issue for the vast majority.

[TNLI]

38 minutes ago, Tony Brooks said:

 

This forum is not here for your specific needs, many others read it and ask advice. The fact that you may have discounted the idea of driving an AC generator off a drive belt does not mean that it is not fitted to any other bats so when thinking about engine power all the loads on engines need taking into account  and in some cases that includes a Travelpower. As an example 2000 Watts output requires 2000/749 to get hp and that equals just over 2.5hp assuming 100% efficiency, but it won't be 100% efficient so even if its 50% efficient (which I doubt) you are still looking at an extra 5 hp plus the load from any other alternators.

 

Real life experience simply does not support your assertions. We don't need frequent de-cokes, We don't suffer much from excess carbon build up, injectors seem to still be producing an acceptable spray pattern (judging by engine smoke and starting) after 10 to 20 years or more.

 

This experience includes hire fleets who deliberately under prop their boats to ensure the customers maintain reasonable charging revs and others who over prop to give better stopping power. The problem you perceive are simply not an issue for the vast majority.

Thanks for another polite reply, and the travel power conversion is a tad too expensive, probably why no one so far has said they have one. It seems to be the fancy control box that costs 700 plus quid, as many folks would like to run items of at least 2000W, so combine that with the alternator and pulley, it would cost over a grand, so plan B is to fit the old alternator to a 4 NiCad batteries that I plan to use for a 10hp, (7 if you don't like it overheating), go cart motor mounted on the prop shaft, IF there is room aft of the gearbox away from the new stainless silencer.

  I've been looking at a better reasonable price waterproof 240v inverter capable of powering my 750W microwave or pot boiler. The real McCoy marine units are incredibly expensive and most are not even waterproof, but the solar panel folks seem to be making some waterproof ones that might be of interest that might be of interest, as they seem very popular:

1600W MPPT Solar Charge Controller Waterproof Grid Tie Inverter AC120/230V+WIFI | eBay (Also on Amazon)

 

I would note that in terms of reducing pulley bearing wear, it does help to put a load on both sides, and I can mount my old 2nd 12v alternator directly opposite the present new 70 amp one, once I figure out where to buy the brackets and get around to cleaning up the old 55A alternator which will need a new rectifier and brushes unit.

 

As regards comments about the BMC diesels use at low power on canals not causing any real issues, that is just not true, many operators just accept that they smoke a bit, which apart from a short puff when cold started they should run clean. The reasons for that smoke are many, but top of the list is gummed up injectors, worn rings and valve guide oil seals. Most of the wear results from the effects of too low a cylinder head temperature. If you are interesting in add on engine systems, many old aircraft engines have EGT (Exhaust gas temperature) sensors in each part of the manifold to allow the mixture controls to be adjusted. They only have one normal temp gauge with a 4 way switch. That system is very good at allowing an operator to see which cylinder might need attention first. I've had to suffer diesels that smoke a bit on many occasions, but don't intend to do it again. Such engines also burn more fuel and oil, some are so bad you don't need to change the oil, as it needs topping up every trip!

Edited January 24, 2022 by TNLI

[Tracy D'arth]

How far off topic are the Mods going to allow this thread to go? 

 

It will be talking about football soon...

[StephenA]

16 hours ago, TNLI said:

Yes they do make a real difference. The belt on my engine is a GATES AUTO MASTER part number 6220MC, which is a toothed belt. If you have a smooth belt try changing it to that belt or its Continental equivalent, as there is no way it will slip unless something is wrong with the alternator or circulating pump etc.

 

 

 

Again, once again you have not read what I said and have just replied with your view : I said that we have a toothed belt on it and it is all tensioned correctly.

 

There is a max amount of power you can transfer with a V belt and there is nothing wrong with our alternator (which is where the slip is happening).

 

 

16 hours ago, TNLI said:

 

 

There is no such thing as a rebuild cycle, the only reason why an old classic built donkey needs to be scrapped is if the operator does not get the crank inspected and polished up by a specialist company as I plan to do, and the crank fails, or lack of spare parts. The only spare I can't seem to find is a new torsional vibration damper bearing. Not even seen any used ones listed so far.

 

Our engine is at it's max ring size - so when compression starts to drop then the only solution is boring out, adding sleeves and boring those. With that all the other associated work it means that it's not economical to do that.

[StephenA]

6 hours ago, TNLI said:

As regards comments about the BMC diesels use at low power on canals not causing any real issues, that is just not true, many operators just accept that they smoke a bit, which apart from a short puff when cold started they should run clean. The reasons for that smoke are many, but top of the list is gummed up injectors, worn rings and valve guide oil seals.

 

There aren't any real issues with BMCs being used on canals - they've been in use since the early 70s.

 

They do smoke, not much but there is always a little bit of smoke. There is a very good reason why there were so many BMC 1.5 lying around in the early 70s when leisure boating really took off....

[TNLI]

18 minutes ago, StephenA said:

 

Again, once again you have not read what I said and have just replied with your view : I said that we have a toothed belt on it and it is all tensioned correctly.

 

There is a max amount of power you can transfer with a V belt and there is nothing wrong with our alternator (which is where the slip is happening).

 

 

 

Our engine is at it's max ring size - so when compression starts to drop then the only solution is boring out, adding sleeves and boring those. With that all the other associated work it means that it's not economical to do that.

I've never heard of anyone abusing a diesel often enough to reach the max ring size available. You do get the odd over heating case that warps the head so that it can't be skimmed again, although you can find another used head, but that would push the rebuild cost up.

I really don't understand why other than a cheap soft belt, or misalignment a belt that should be perfectly good for a 70A alternator would slip.

[StephenA]

16 hours ago, TNLI said:

In addition to the Beta Greenline 38 fitting the mounts, there is a new Chinese made copy, (CANALINE), I looked at, but it's not been in production for long enough to be a sensible choice. It only costs about 5 grand, but you always get what you pay for. It only has a 3 year warranty, the Beta has a 6 year one and they don't seem to have a keel cooling option, whereas Beta do, so if I did go mental and decide to sell my donkey because the dreaded torsional damper bearing is kaput, I would fit a new Greenline 38, OR if I decided that the power reduction was acceptable, a fully reconditioned Bukh 24 from Marine Enterprises Ltd.

 

Canaline engines not been in production long enough? There are threads on here dating back 7 years about them - some of those talking about engines that have been in use for 4 years and are in use by quite a lot of hire fleets. So that makes 11 years at least and in common usage.. how long does something have to be in production before its deemed sensible?

8 minutes ago, TNLI said:

I've never heard of anyone abusing a diesel often enough to reach the max ring size available. You do get the odd over heating case that warps the head so that it can't be skimmed again, although you can find another used head, but that would push the rebuild cost up.

I really don't understand why other than a cheap soft belt, or misalignment a belt that should be perfectly good for a 70A alternator would slip.

 

If that never happened then people wouldn't sell sleeves or oversize pistons for the BMC - and we're not talking about head warping here.

 

As for V belts and power output .... you do the math...

 

https://roymech.org/Useful_Tables/Drive/Vee_belts.html

Edited January 24, 2022 by StephenA

[Tracy D'arth]

2 hours ago, StephenA said:

 

Canaline engines not been in production long enough? There are threads on here dating back 7 years about them - some of those talking about engines that have been in use for 4 years and are in use by quite a lot of hire fleets. So that makes 11 years at least and in common usage.. how long does something have to be in production before its deemed sensible?

 

If that never happened then people wouldn't sell sleeves or oversize pistons for the BMC - and we're not talking about head warping here.

 

As for V belts and power output .... you do the math...

 

https://roymech.org/Useful_Tables/Drive/Vee_belts.html

I believe the Canaline  units are Taiwanese, Or maybe Korean, I may be wrong. Not as often at TNLI though.

 

Calcutt had a yard full of 60thou overbored  dead blocks. Some of these engines have done a million miles, been bored out 3 times. TNLI knows nothing about how many have been remanufactured time and again.  Or much else either. These units date from the early 1960s.

Abuse has nothing to do with it, simply huge numbers of hours use. Warping heads and blocks are not the killer. Never were.

2 hours ago, TNLI said:

I've never heard of anyone abusing a diesel often enough to reach the max ring size available. You do get the odd over heating case that warps the head so that it can't be skimmed again, although you can find another used head, but that would push the rebuild cost up.

I really don't understand why other than a cheap soft belt, or misalignment a belt that should be perfectly good for a 70A alternator would slip.

90A is accepted as close to the maximum with an A section single  cogged V belt on a 3 pulley set up. You can do a bit better on a 2 pulley drive.

Edited January 24, 2022 by Tracy D'arth

[Tony Brooks]

53 minutes ago, Tracy D'arth said:

I believe the Canaline  units are Taiwanese, Or maybe Korean, I may be wrong. Not as often at TNLI though.

 

I think the base engines are Koto Sanygon of Japan so a similar heritage to Kubota and Mitsubishi. I also think the UK mariniser started out marinising the well thought of Isuzu diesels so beloved of hire fleets. Not exactly an unproven product.

[Tracy D'arth]

12 minutes ago, Tony Brooks said:

 

I think the base engines are Koto Sanygon of Japan so a similar heritage to Kubota and Mitsubishi. I also think the UK mariniser started out marinising the well thought of Isuzu diesels so beloved of hire fleets. Not exactly an unproven product.

They are a product of Kioti Daedong in South Korea.      https://www.kioti.com/about-us/daedong-corporation/

 

Found on the internet.

[Tony Brooks]

Just now, Tracy D'arth said:

They are a product of Kioti Daedong in South Korea.      https://www.kioti.com/about-us/daedong-corporation/

 

Found on the internet.

 

so not quiet the pedigree then.

[StephenA]

2 hours ago, Tracy D'arth said:

Calcutt had a yard full of 60thou overbored  dead blocks. Some of these engines have done a million miles, been bored out 3 times. TNLI knows nothing about how many have been remanufactured time and again.  Or much else either. These units date from the early 1960s.

Abuse has nothing to do with it, simply huge numbers of hours use. Warping heads and blocks are not the killer. Never were.

 

Basically that's what's happened to ours - last rebuild back in about 2005 we were told that it was basically at its max bore / ring size. We got it in 1985 after it had been taken out of another boat. We believe it came from an industrial background before that.

[TNLI]

25 minutes ago, StephenA said:

 

Basically that's what's happened to ours - last rebuild back in about 2005 we were told that it was basically at its max bore / ring size. We got it in 1985 after it had been taken out of another boat. We believe it came from an industrial background before that.

So it seems you purchased an engine that had been rebuilt too many times already. Oddly enough I suspect the reason for some of that wear relates to fuel contamination in the oil, in addition to the use of low power, as very few owners are sniffing their hot dip sticks, or sending off an occasional used oil sample for testing. 

Half of all engine wear results from corrosion and although that can result from the use of cheap engine oil for too long an interval, simply stopping and starting too often as you go through the locks or stop to visit a pub is also bad news in engine wear terms. 

Most canal boats are only used for half the year in terms of say long 10 hour trips, so if you compare that with fishing boat diesels, they should only need rebuilding about every 30 years or so in terms of a full rebuild where new rings are fitted, rather than changing injector tips and fitting a new HP pump. 

It would also be interesting to know how many of the BMC engines that were dumped or sold off were caused by failures relating to lack of oil or serious overheating.

One point for anyone buying an old BMC would be to try and find out how many times the engine has had new rings fitted. I suppose some hire companies keep engine logs and records, but most private owners do not, although trying to find a BMC 1500 in good working order is very difficult. I

I would not think about buying a new type of diesel until the type has been in use for about 20 years, then you will know if they are good or not.

[StephenA]

27 minutes ago, TNLI said:

So it seems you purchased an engine that had been rebuilt too many times already. Oddly enough I suspect the reason for some of that wear relates to fuel contamination in the oil, in addition to the use of low power, as very few owners are sniffing their hot dip sticks, or sending off an occasional used oil sample for testing. 

Half of all engine wear results from corrosion and although that can result from the use of cheap engine oil for too long an interval, simply stopping and starting too often as you go through the locks or stop to visit a pub is also bad news in engine wear terms. 

Most canal boats are only used for half the year in terms of say long 10 hour trips, so if you compare that with fishing boat diesels, they should only need rebuilding about every 30 years or so in terms of a full rebuild where new rings are fitted, rather than changing injector tips and fitting a new HP pump. 

It would also be interesting to know how many of the BMC engines that were dumped or sold off were caused by failures relating to lack of oil or serious overheating.

One point for anyone buying an old BMC would be to try and find out how many times the engine has had new rings fitted. I suppose some hire companies keep engine logs and records, but most private owners do not, although trying to find a BMC 1500 in good working order is very difficult. I

I would not think about buying a new type of diesel until the type has been in use for about 20 years, then you will know if they are good or not.

 

There you go with the fuel contamination in the fuel thing again. No fuel contamination ever since we've had it.

 

We've had the engine for over 35 years - had one "rebuild" at Calcutt that was a sham ( I suspect they just did the top end)  and a solid rebuild in 2005 which is still going strong with good cold starting.  Until recently we were doing 500 -700 mile trips in the summer and often a 200+ mile trip in the autumn

 

I'd previously stated that I wasn't going to respond your posts - I was stupid and didn't stick by that decision

 

Edited January 24, 2022 by StephenA

[TNLI]

On 23/01/2022 at 09:24, Tony Brooks said:

 

I think that flushing a really neglected engine will more than likely block the new oil filter with debris that were softened but not totally removed from the internals.

 

Use oil of the correct API and SAE spec. and don't push the oil change intervals so probably the best  way to keep the engine clean inside for post about 1955 designed engines.

Yeabut, most of the posters in this forum do not use a sensible major brand oil. The OP for example listed one I have never heard of, and when you combine that poor oil with fuel contamination you have the perfect oily brew to wear out an engine prematurely. That's why I would pay more attention to doing a pre oil change idle only flush, and using a fuel injection purge rather than a fuel additive.

It's very noticeable in this forum that many posters are keen to deal with the problems associated with the abuse of their engines, but have little interest in how you prevent those problems occurring in the first place. That is very different to car forums, where preventing premature wear and increasing fuel economy is of more interest. 

 

  If anyone does have an engine with worn rings or bearings and they don't want to rebuild the engine, then it is worth trying one additive that I've used in old diesels to good effect, and that is Liqui Moly Ceretec:

P000017-Cera Tec-49-en (liqui-moly.de)  or the cheaper dubious copy: Ceramic Oil Treatment | STP.com

Make sure you only add it to the block and not the gearbox, as although it is a ceramic particle suspension that is the main active ingredient, it does contain some Moly which could cause a hydraulic box to slip. 

If you combine that additive with making sure your oil stays thick by using a 20W50 and shorter oil change intervals if it is getting thinned out by fuel contamination, it should make a significant difference. The older the engine the thicker the oil needs to be in wear reduction terms, so in desperate cases I have used an oil thickener:

 P000068-Pro-Line Visco-Plus-20-en (liqui-moly.de)  Lots of cheaper copies including the original STP thickener, but you get what you pay for and the Germans make by far the best additives for both oil and fuel. They actually do what it says on the PDS, (Product Data Sheet).

  Obviously I would note that using an oil thickener in winter is not a good idea if your engine block does not have a pre heater or the bay it's in is cold, and in cold start wear reduction terms a heat pad is real good news if you are on shore power. This is the one I'm thinking of fitting at present:

Wolverine Silicone Pad Heater 4 x 4" 125w 12v - Engine Oil Sump Fuel Filter | eBay

Edited January 24, 2022 by TNLI

[TNLI]

11 hours ago, StephenA said:

 

There you go with the fuel contamination in the fuel thing again. No fuel contamination ever since we've had it.

 

We've had the engine for over 35 years - had one "rebuild" at Calcutt that was a sham ( I suspect they just did the top end)  and a solid rebuild in 2005 which is still going strong with good cold starting.  Until recently we were doing 500 -700 mile trips in the summer and often a 200+ mile trip in the autumn

 

I'd previously stated that I wasn't going to respond your posts - I was stupid and didn't stick by that decision

 

There is no way you will know if your oil is contaminated with diesel until it reaches about 10% when it is possible to smell it on a hot dip stick and the viscosity of the oil will be notably thinner. The limit for long term block wear is 2%, so that is far too late in terms of real harm to the engine.

 

The article below from Practical Sailor is a good one and it does describe how a simple paper test can be done and if you are interested in reducing the interval between rebuilds it is worth reading:

DIY Engine Oil Tests - Practical Sailor (practical-sailor.com)

 

There are a number of fairly cheap test devices, although I've never used one they are supposed to be good at detection fuel contamination:

Oil Quality Tester, Engine Oil Analyzer Diesel Analyzer Car Digital Stroke Plastic Motor Engine Detector Gas Diesel Analyzer for diesel Engine oil,Gasoline Engine Oil, : Amazon.co.uk: Automotive

 

I've not done an oil blotter test, but it helps to use the right type of paper card, so it's worth reading about how they are done in Bobs The Oil Guy forum:

Blotter Spot Test Procedure | Bob Is The Oil Guy

 

If anyone can find a blotter test kit let us know, as the links above do refer to using a blotter test kit, but I can't seem to find one in Google.

 

Surprised you have a poor opinion of Calcutt Boats, although why did they not inform you of the exact nature of the rebuild before they did it, and was it still smoking after they finished ??

 

Edited January 25, 2022 by TNLI

[Tony Brooks]

8 minutes ago, TNLI said:

The article below from Practical Sailor is a good one and it does describe how a simple paper test can be done and if you are interested in reducing the interval between rebuilds it is worth reading:

DIY Engine Oil Tests - Practical Sailor (practical-sailor.com)

 

Nothing new there. Is/was fairly common on large vehicle fleets. Surprising there is no mention of doing a crackle test for coolant contamination as a discrete topic.

[TNLI]

TBN-Whats-in-it-for-Me.-Prof.-Dr.-Boris-Zhmud-Head-of-R-D-BIZOL-Lubricants-GmbH.pdf (lube-media.com)

 

That article is very good and it does say that for an older diesel that does not have a DPF, the TBN should be high at 10 to 12, which is more that the 9 for the oil I'm using. If you are using a non major brand oil with a low TBN, that combination could prove to be a real block killer if the oil is contaminated by blowby products or diesel from a bad HP or lift pump.

 

One question I asked on another thread is if anyone good at online searches can find a cheap test kit to do a blotter test for diesel in the oil. I'm almost certain that many BMC that start smoking result from the use of poor quality engine oils combined with fuel contamination, and the simple blotter test will show if used oil is contaminated, but the kits mentioned in various articles seem very hard to find in Google search. So if anyone finds one please post a link. Unfortunately when I looked for a kit the oil labs who nearly all major oil companies have, seem to bury the results for any obvious key words. It seems they do not want anyone to know about them.

Edited January 25, 2022 by TNLI

[Tony Brooks]

FWIW when we did oil testing at college we used ordinary blotting paper but as TNLI's link says any non-coated thicker paper will do.They used the term cardstock which really means thick paper (say in  excess of100 gpm). I suspect any porous paper would do so maybe lining paper. If you wanted you could pencil some circles on the paper to give a guide across a number of tests.

 

The actual resultant pattern will vary according to the paper's porosity but it is a comparative test not a definitive one so, as the link shows, a control test should be done on a known good engine.  Ideally one would then contaminate a good engine with a known small amount of fuel, run it to mix well and then do another control test.  Preserve those two tests and use them to help assess later real life tests. If the test paper is changed then the results will alter according to how absorbent it is.

 

For completeness. If coolant contamination is suspected a quick and dirty test is to drop some oil onto a hotplate. If it crackles it is water boiling. Quicker than waiting for a blotting paper test and probably not as reliable for low rates of contamination. Don't drip too much, it is very likely to catch fire and if not it will smoke well!

[TNLI]

On 25/01/2022 at 12:55, TNLI said:

TBN-Whats-in-it-for-Me.-Prof.-Dr.-Boris-Zhmud-Head-of-R-D-BIZOL-Lubricants-GmbH.pdf (lube-media.com)

 

That article is very good and it does say that for an older diesel that does not have a DPF, the TBN should be high at 10 to 12, which is more that the 9 for the oil I'm using. If you are using a non major brand oil with a low TBN, that combination could prove to be a real block killer if the oil is contaminated by blowby products or diesel from a bad HP or lift pump.

 

Ooops! When a diesel start to sludge up because the oil has been used long enough to result in the detergent additives failing to function, fuel contamination actually helps to stop the oil sludge forming to some extent, particularly if it has a high Bio diesel content, as that is a good natural solvent. What I should have said, "Or the oil has a low level of DZZP, (Zinc compound), inclusive additive). Sludge results in poor oil flow and local overheating, but the layer of Zinc can resist the extra wear for a while in terms of direct wear and corrosion protection.