BMC Captain Diesel

[fisherman]

There's HP and HP. In the dim distant we used to have races at the local regattas, and we had mostly Stuart Turners, Brits, Listers, all 6/8/10hp. Someone turned up with a Morris 10hp car engine, which produced possibly 35-40hp, the 15ft boat stood on its tail. We protested loudly that it was BHP.
Consider the Kelvin Poppet petrol paraffin 50/60hp. 4 cyl, 29 litres and weighed over a ton. 400 rpm.
Try a Ford Dover 120hp against a Gardner 120hp: chalk and cheese.

 

[TNLI]

Bore glazing and polishing in diesel engines – Cox Engineering

That's well worth reading and it does confirm the main cause is long periods of low power, and failure to vary the RPM or rev up to max continous for a short while where possible.

From the engine oil point of view, they do point out the importance of not using non major brand, or dealer brand oils, and are keen on heavier grades. So 40 instead of 30 if you can start with straight grades, (Straight 40s are unobtainium), and avoid 0w30 or 40s even though they are listed by some engine companies for Artic cold starts.
They failed to say much about fuel contaminants, or the effect of too high a level of Moly, (Mo), friction modifyer additive in the oil.

At the end of the day, it really is a matter of not fiiting too big a donkey and most important of all, not using it as a battery charger. If you need to juice up your batteries and solar panels are not enough, or the shore power mafia charge an arm and a leg, don't forget that a new air cooled diesel generator can now be purchased for around 600 quid! OK it's only 3kW, but a real McCoy 5kW job is only around 1200 quid. That's a lot less than a good engine rebuild!

I'm researching cheapish diesel generators at present, so here is my list in order of cost, they are all air cooled and seperate tank ones:

Neilsen BDe3500e 3kW and 8.3A for around 600 quid.
Black and Decker Boxed orange BX 5300e 5kW, but no 12v around 1100 quid.
Hyundai Direct white boxed 6kW and 12v, 1400 to 1600 acording to extras like remote start.

No idea which one at present, although I do like the orange boxed up B & D. Not concerned about the lack of 12v outlet, as battery chargers are cheap and it complicates the wiring. What I need 240v for is the freezer, occasional use of a single hot plate and heating up what might be a stone block storage heater in winter.

 

[Boater Sam]

Bore glazing and polishing in diesel engines – Cox Engineering

That's well worth reading and it does confirm the main cause is long periods of low power, and failure to vary the RPM or rev up to max continous for a short while where possible.

From the engine oil point of view, they do point out the importance of not using non major brand, or dealer brand oils, and are keen on heavier grades. So 40 instead of 30 if you can start with straight grades, (Straight 40s are unobtainium), and avoid 0w30 or 40s even though they are listed by some engine companies for Artic cold starts.
They failed to say much about fuel contaminants, or the effect of too high a level of Moly, (Mo), friction modifyer additive in the oil.

At the end of the day, it really is a matter of not fiiting too big a donkey and most important of all, not using it as a battery charger. If you need to juice up your batteries and solar panels are not enough, or the shore power mafia charge an arm and a leg, don't forget that a new air cooled diesel generator can now be purchased for around 600 quid! OK it's only 3kW, but a real McCoy 5kW job is only around 1200 quid. That's a lot less than a good engine rebuild!

I'm researching cheapish diesel generators at present, so here is my list in order of cost, they are all air cooled and seperate tank ones:

Neilsen BDe3500e 3kW and 8.3A for around 600 quid.
Black and Decker Boxed orange BX 5300e 5kW, but no 12v around 1100 quid.
Hyundai Direct white boxed 6kW and 12v, 1400 to 1600 acording to extras like remote start.

No idea which one at present, although I do like the orange boxed up B & D. Not concerned about the lack of 12v outlet, as battery chargers are cheap and it complicates the wiring. What I need 240v for is the freezer, occasional use of a single hot plate and heating up what might be a stone block storage heater in winter.

Please do not moor near me with an air cooled diesel generator, boxed or otherwise. The only drastic engine failure in a boat I have ever seen was a Mercedes which was in good order until the new owner used a Molybdenum additive. It wrecked the engine completely in short order.

 

[TNLI]

Please do not moor near me with an air cooled diesel generator, boxed or otherwise. The only drastic engine failure in a boat I have ever seen was a Mercedes which was in good order until the new owner used a Molybdenum additive. It wrecked the engine completely in short order.

If I mention an oil additive, I mean one that is part of the group of additives helping the base stock function correctly, NOT some bottle of extra Moly. Adding extra additives invalidates the engine warranty and in general terms, is a daft idea unless you really do know what you are doing. The only companies I trust when I want to either flush out some varnish deposits from a turbo feed line, or extend the life of an oil that is suffering the consequencies of diesel fuel contamination are Liqui Moly and Castrol. The Castrol classic car section does have a very good pre oil change flush additive that is used at idle and is a very good way of cleaning up a sludge or varnish monster donkey.

Never heard of a Moly additive damaging an engine, although Caterpillar along with a few other engine makers do point out that they would prefer it if all owners of their diesels avoid oils containing Moly. The reason for that ban was that one particular metalic element in the upper cylinder area seem to react with it, causing significant additional corrosion that shows up in used oil analysis as high levels of Iron.
Moly (Mo) is an integral part of the additives in over half of all engine oils, with actual amounts varying between 50 and 200 ppm, although some of the best German standard sythoils, like Liqui Moly High Tech 5w40 (A3/B4) do not contain it. Basic Castrol GTX 15w40 (A3/B3) is also Moly free.

Air cooled generators do not last as long as water cooled ones, like the famous Onan series. If you do buy or have a diesel gen set, check to see if the low oil pressure warning or auto cut out system works by shorting the sensor terminals, and be careful about drips reaching the generator itself. It's as important to change the oil at least as often as the user manuals says, and use the best oil available. For a gen set it's often a 10w30, rather than a 40. Major brand or dealer supplied only!

If you are overseas and looking for oil, I would include the main national oil company in my list of major brand oil companies, (I've never purchased a non major brand oil due concerns about both contents and quality assurance issues. So in Spain for example I would look for a good Cepsa oil in a fishermans coperative shop. Cepsa also market good sealed car and truck batteries that did well in a 3 year circumnavigation. I think the oil I used was a straight 30, and the batteries were standard 12v 95 Ah sealed Lead acid ones. Their capacity was down to about half of the original Ah figure by the end of a tough 3 year trip.

 

[TNLI]

Yes they're good engines, capable of constant full-power running for months on end, with regular oil changes. I spent a whole season thrashing one on a passengercarrying narrowboat, 7 days a week of full revs, no issues at all. It was eventually replaced for cosmetic reasons by a Russel Newberry, which was a disaster.
There are plenty of mechanics with intimate knowledge of them, and cheap spares. Much better to find one of these in an old boat, than a 70's Volvo! The common PRM boxes are also very long lasting.

The BMC I'm trying to buy, (Final desscision by Friday next), has a hydraulic box of some type. Anyone know which normal manual box I need to fit to replace it, as I need to fit a generator/ secondary dtrive motor (48v go cart engine), so if the deal goes through I will sell the hydraulic box and buy the best mechanical one that matches. No idea which one at present, as they fitted about 4 different type of box ??

 

[Boater Sam]

There is no normal box. The ones used are ranged from the ancient Morris gearbox through ancient Newage B box to nasty Hurths and good PRM 90 and 120.
But there are TMC and Techno-drive, Borg Warner etc.
I would favour a PRM from experience.

 

[TNLI]

There is no normal box. The ones used are ranged from the ancient Morris gearbox through ancient Newage B box to nasty Hurths and good PRM 90 and 120.
But there are TMC and Techno-drive, Borg Warner etc.
I would favour a PRM from experience.

Thanks for that good reply, so I will need to buy or swap for a PRM, (Marine Enterprises stock most of the better gearboxes and recondition them)

 

[Rappey]

Why nasty hurths ? I quite like them. Very popular on bmc.
I went for a year where I would put it in gear but nothing would happen, rev the engine and it would jump into gear and off you go!
Turned out it was and loose clamp in the morse control . ?
Lack of oil changes and abuse and the little hurth still keeps working.
I read somewhere, possible a manual that you can shift from forwards to reverse without lowering the engine revs.
Last time I looked a box was £500-650. Wow, now they are over £1000

 

[TNLI]

Why nasty hurths ? I quite like them. Very popular on bmc.
I went for a year where I would put it in gear but nothing would happen, rev the engine and it would jump into gear and off you go!
Turned out it was and loose clamp in the morse control . ?
Lack of oil changes and abuse and the little hurth still keeps working.
I read somewhere, possible a manual that you can shift from forwards to reverse without lowering the engine revs.
Last time I looked a box was £500-650. Wow, now they are over £1000

If you need a recon gearbox, I would try Marine Enterprises just North of Dorchester. There are also several other very good companies around the Norfolk broads that sell reconditioned gearboxes.

The main reason for a box needing a full rebuild, is that the output bearing is starting to fail and has chewed up the associated oil seal as a result of the associated vibration. If that main bearing is bad, then the other input bearing will also be worn enough to justify its replacement, along with its oil seal. If the box main bearings are worn, nearly all of the other bearings or shaft bushes and seals will need to be done.
The cost of the recon boxes seems to vary a lot from company to company, and with the popularity of the gearbox concerned. Should be less than 500 for most BMC boxes.
Lack of box oil or fluid changes might well be the cause of most failures, BUT it's not the only cause. Failure to clean the box fluids screen filter or magnetic plug, (No idea what BMC did to ensure metal deposits in the oil are removed)
I've also seen manual gearbox input main bearing that was starting to fail, and when I looked at it, it was obvious that the bearing had started to fail because there was a leak in a panel just above that resulted in sea water dripping down between the back of the engine and the gear box. That leak was also effecting the gearbox output bearing.

 

[TNLI]

Thanks for that good reply, so I will need to buy or swap for a PRM, (Marine Enterprises stock most of the better gearboxes and recondition them)

Which gearboxes in that list are hydraulic ones, as the box on a badly abused BMC I'm trying to buy has a hydraulic box. Hope it's a Borg Warner, as they seem to be very good ??

 

[Boater Sam]

Do you me

Which gearboxes in that list are hydraulic ones, as the box on a badly abused BMC I'm trying to buy has a hydraulic box. Hope it's a Borg Warner, as they seem to be very good ??

Do you mean in my list? Quoting your own quote is most confusing. You asked for mechanical boxes, that's what I gave you. None were hydraulic.
Most popular hydraulic on a BMC1.5D would be the PRM 150 and its earlier incarnation the Delta with its dedicated bell housing. Both ar ally clamshells.
Some used the cast steel PRM 160, overkill as its a bomb proof box.

 

[Boater Sam]

Why nasty hurths ? I quite like them. Very popular on bmc.
I went for a year where I would put it in gear but nothing would happen, rev the engine and it would jump into gear and off you go!
Turned out it was and loose clamp in the morse control . ?
Lack of oil changes and abuse and the little hurth still keeps working.
I read somewhere, possible a manual that you can shift from forwards to reverse without lowering the engine revs.
Last time I looked a box was £500-650. Wow, now they are over £1000

Ridiculous spares prices, clunky changes, short lives. The cost of 2 clutch kits rights the box off.

 

[Gary Fox]

I wouldn't change from forward to reverse without lowering the revs right dowm, on ANY gearbox unless it had a pure fluid coupling. That rules out all yacht and ship boxes AFAIK.
( I've heard of it being done on an Alvis Stalwart from top speed, at the taxpayers expense by some nutters in green clothes if that is believable..)

 

[fisherman]

I built a boat under SFIA regs and the inspector did a full ahead/astern test. Kept the boat for 7 years. Not heard of any subsequent problems. PRM box.

 

[TNLI]

Thanks for that, and do you know the number of the PRM box fitted, as there seem to be 2 choices, the PRM 90, OR the 120 ??

No idea if it matters which one, and I might not have much of a choice anyway. Not seen the engine up close and personel yet, so not sure which hydraulic box is involved. Is the best one the Borg Warner, or some other box ??
I'm hoping someone will say the Warner, as one of my sponsors thinks they are the dogs small round things in reliability terms. Knowing my luck the hydraulic box fitted will turn out to be made by some other company, as I can't see the manufacturers plate in the video clip or pictures sent by RNLI engineering.

 

[TNLI]

I wouldn't change from forward to reverse without lowering the revs right dowm, on ANY gearbox unless it had a pure fluid coupling. That rules out all yacht and ship boxes AFAIK.
( I've heard of it being done on an Alvis Stalwart from top speed, at the taxpayers expense by some nutters in green clothes if that is believable..)

Definite no no on any mechanical box, but no problem on most modern ships, or even larger boats, as they have a modern TCU, (Transmission Control Unit), connected to the engine that acts like an e throttle and engine ECU, in that it does not allow too fast a change in either power of gear use.

 

[TNLI]

Do you me

Do you mean in my list? Quoting your own quote is most confusing. You asked for mechanical boxes, that's what I gave you. None were hydraulic.
Most popular hydraulic on a BMC1.5D would be the PRM 150 and its earlier incarnation the Delta with its dedicated bell housing. Both ar ally clamshells.
Some used the cast steel PRM 160, overkill as its a bomb proof box.

Sorry failed to check that post. So the plot thickens and I will reply before the weekend, in terms of which box is fitted.

 

[Gary Fox]

Definite no no on any mechanical box, but no problem on most modern ships, or even larger boats, as they have a modern TCU, (Transmission Control Unit), connected to the engine that acts like an e throttle and engine ECU, in that it does not allow too fast a change in either power of gear use.

Foolproof until it goes wrong.. an old skool E/R telegraph with no bridge control is also a good system.

 

[TNLI]

Foolproof until it goes wrong.. an old skool E/R telegraph with no bridge control is also a good system.

Yep, the early big ship engine controls were not that great in terms of simply giving a warning and then reverting to manual. That type of engine control system was very similar to the e throttle, engine ECU and TRU fitted to many diesels that had an automatic transmission made by ZF in Germany from around 2004 onwards. Mostly Mercedes and Audi mid range cars, numerous bigger vans, trucks and buses. The ZF auto gearbox series has turned out to be incredibly good with the 7 and 9 speed boxes better than any manual gearbox system in both fuel economy and race performance terms, (9 speed version only). They are also very reliable in terms of failure rates, and in most failures they simple revert to limp home mode, rather than the marine equivalent, which reverts to full manual control. The more moderrn marine versions are dual channel, so all you get is a warning and a diagnostic code that identies which board or box needs to be changed.

OFF TOPIC
Marine gearbox and engine design was aimed more at trying to make sure an engine lasted a very long time in the old days, but alas the more modern marine engines are designed around achieving the best possible fuel economy figures, whilst making certain that they don't fail until the warranty has expired. One nasty design aspect that confuses new owners concerns oil or transmission fluid viscosity recommendations, as using a thicker oil does result in a reduction in MPG figures due to increased internal resistance. So ZF and all of the big engine or transmission companies recommend and sell oils and fluids that are rather on the thin side for a post warranty engine.
Liqui Moly are honest when you use their guides and lists of which oil to use for a particular application, so they often recommend 2 oils or fluids, one for OEM standard use, (Max fuel economy), and another thicker version for post warranty max engine life performance. The difference is very important, as they do make some of the worlds best transmission system oils and fluids, BUT you do need to pick the correct one when 2 different ones are listed.

The big trick in terms of figuring out which oil or hydraulic fluid to use in an older engine or box, is to find out which oil was the very first oil used in a new engine, and then to compare the viscosity figure, or 2 figures in the case of a multi grade, along with a list of the actual amounts of all the different additives included in the oil. You then check out the 4 major brand oil companies for the nearest match.
So for example the diesel in my old Volvo had Castrol Mag 10w40 listed as OEM oil, BUT for severe use in hot climates had a second OEM oil which was an HC synthetic 15w40, AND a recommendation that the OCI (Oil Change Interval), be reduced to half of the normal figure. The severe service 15W40 (For hot countries only) full synthetic is only available in the USA and very expensive. Nearest match is Mobil 1 10w60 EL (Extended life, not the race oil EP version). The additives are almost the same, and it is not much thicker than the OEM 15w40, as that oil was a the top of the 40 range, whilst the Mobil one is at the bottom of the 60 range, and it was designed by Mobil for older engines.

So for a marine example lets say the OEM oil for a BMC 1.5 used in the tropics was a straight 30 mineral base oil with high levels of detergents and Zinc base anti wear additives included. So if your BMC is in good order and you are in the tropics, just use a straight mineral oil made by a major brand oil company, BUT if your engine is badly worn, or has an injection pump that is old enough to cause fuel contamination of the oil, use straight 40 grade part synthetic AND change the oil twice as often as recommended.

Alas what happens in the real world, is some owners and operators just put in a 30 grade from a local supermarket or fishermans cooperative that is not made by a major brand oil company, and make no attempt to find a modern equivalent. They also fail to look up what is meant by the term, "Severe Duty", as it varies according to the company concerned . It might be that if you are out of limits on the cold side of the table, an 0W30 is required, (It's not possible to make a mineral base 0W30), orif you need an oil for both cooler climates but with a visit to the tropics before the oil is changed you will have to use a 10w40 part, or HC, (Hydro Crack), synthetic. In oil change interval terms, a straight oil lasts longer than a multi grade, and if you are not able to match the operating temperature in viscosity terms, that will consitute severe service, so the associated oil change interval should be reduced by half.

The BMC was made in the days when most sensible garages and even BL recommended a different oil is used in the winter to the summer. Back in the 60's they could not make a cheap HC or German standard full synthetic, so I think 10W40 was the only option during the winter, as SAE 20 mineral base oil was too expensive, and problematic in warranty terms if it was not changed before the summer. The summer oil was a 15w40, or 30 grade.

The fiasco over oil filter equivalent is even worse, as many owners or operators just buy any old cheap filter, and the failure to comprehend the damage done when the media falls apart, or internal oil pressure relief valve in a spin on filter fails to open during a cold start, does just as much harm during a cold start in particular as using a junk oil rather than a major brand. My only recommendation if you really can't find the OEM recommended dealer supplied oil filter, is to make sure it really was made and sold in Germany. Alas there are so many internet based scams where a far Eastern oil filter is sprayed a different colour and has the correct name and numbers printed on it, that I order mine direct from Germany or the USA in a few difficult cases.

For a BMC it might mean buying filters from ASAP, who do not sell copies as far as I'm aware, until I find out the Mann, (In Germany not the far or mid East), equivalent direct from their main dealer in Germany.

 

[TNLI]

Rather dubious part of previous post:

I'm researching cheapish diesel generators at present, so here is my list in order of cost, they are all air cooled and seperate tank ones:

Neilsen BDe3500e 3kW and 8.3A for around 600 quid.
Black and Decker Boxed orange BX 5300e 5kW, but no 12v around 1100 quid.
Hyundai Direct white boxed 6kW and 12v, 1400 to 1600 acording to extras like remote start.

Ooops, I posted that before thinking of the health and safety issues involved in installing a gen set meant for use outside, inside a boat. So I would point out that any type of diesel generator can start a fire, or produce a lot of Carbon Monoxide fumes.

So firstly the cabin the generator will be mounted in, is for storage only except when in port or a marina, when it can accomate two people. The cheap generators listed all need an external exhaust system which is already installed, so it just needs an adapter to be fitted. There will be 2 independent CO monitors mounted near the generator, that can also detect smoke. From the fire point of view, the gen set will be mounted within a fire proof enclosure that has an automatic fire bottle, and a fire hose access point so I can flood the entire box if required. One teaspoon of burning oil or diesel can produce a boat full of very thick smoke, so the generator box does need to vent outside. It's not just sitting in the cabin. The actual mounts will be a serious set of through bolted clamps, so no risk of it breaking free.

At the present time I'm favouring the cheaper open frame models, as there is no room inside the covered ones for an auto fire bottle. I also plan to modify the alarm wiring to automatically shut down the engine if the oil pressure drops, or a remote kill switch in the aft cabin is pushed in.
For a canal boat it's far easier to mount a gen set outside than in a dedicated drained and vented fire proof box, which will take some time to make. I even plan to fit a seawater flood valve, as generators don't burn underwater, just in case the surveyor gets interested in it.

It's a real bad idea to install a gen set anywhere near the main cabin or emergency muster point, (Where you gather before abandoning ship). Alas many designs for offshore boats have a gen set that can pour smoke directly into the main cabin if the access door to the generator enclosure or bay is opened.