BMC 1500 what to look for and tips.

[TNLI]

15 minutes ago, StephenA said:

 

I'd certainly not want to rely on a BMC 1.5 to get me across the atlantic.

Thanks for the reply, and can you list your reasons for disliking a marinised BMC 1500, other than the following points I have discovered:

 

1/ Fuel economy not quite as good as a Yanmar 4GM or similar.

2/ Needs the oil changing more often due to HP fuel pump contamination of the oil, (This can be reduced to some extent by changing those seals every year).

3/ Ultra high time engines that have been abused, can like many old diesels, snap their crankshaft trashing the engine, (So the crank must be X ray or very serious dye inspected, or replaced during a full rebuild).

  A lot of folks think there is a real shortage of parts, but I'm not one of them, as all of the parts are available new.

[StephenA]

13 minutes ago, TNLI said:

Thanks for the reply, and can you list your reasons for disliking a marinised BMC 1500, other than the following points I have discovered:

 

1/ Fuel economy not quite as good as a Yanmar 4GM or similar.

2/ Needs the oil changing more often due to HP fuel pump contamination of the oil, (This can be reduced to some extent by changing those seals every year).

3/ Ultra high time engines that have been abused, can like many old diesels, snap their crankshaft trashing the engine, (So the crank must be X ray or very serious dye inspected, or replaced during a full rebuild).

  A lot of folks think there is a real shortage of parts, but I'm not one of them, as all of the parts are available new.

 

2 - we're running an old BMC 1.5 - with several 0s in the serial number.  Industrial flywheel. Been rebuilt at least twice and we have never had any problems with the HP fuel pump contaminating the oil and we've never changed the seals. Last rebuild was before the great floods when we had the boat at Upton

 

Its nothing to do with any of your reasons - it;s just an old engine and I'm not really sure it would survive being thrown around at sea. You talk about 45 degree tilt for a genset - I''m not sure what the max tilt for a BMC 1.5 is - how far can you tilt it before the oil lift stops picking up?  Of course I might be wrong but if I was going to replace our engine now I'd not be looking at another BMC 1.5 just because of the age.

 

As a complete aside the rebuild Calcutt did on our BMC was pretty crap.  Starline at Upton did a much better job (boat still starts first crank after 15 seconds of heaters in Winter even when its been standing for a few months).

 

 

Edited September 3, 2021 by StephenA

[David Schweizer]

6 minutes ago, TNLI said:

Thanks for the reply, and can you list your reasons for disliking a marinised BMC 1500, other than the following points I have discovered:

 

1/ Fuel economy not quite as good as a Yanmar 4GM or similar.

2/ Needs the oil changing more often due to HP fuel pump contamination of the oil, (This can be reduced to some extent by changing those seals every year).

3/ Ultra high time engines that have been abused, can like many old diesels, snap their crankshaft trashing the engine, (So the crank must be X ray or very serious dye inspected, or replaced during a full rebuild).

  A lot of folks think there is a real shortage of parts, but I'm not one of them, as all of the parts are available new.

 

There is nothing wrong with installing a BMC 1.5 in a standard Narrowboat designed to operate on UK canals, I had one for decades and it gave sterling service. But,  and it is a big but, The BMC 1.5 is a marinized road vehicle engine and does not have enough power to propel even a small boat across the sea, for that you need, as already stated, a proper marine unit designed for sea going boats. Why are you unable to understand that?

[MtB]

4 minutes ago, David Schweizer said:

 

There is nothing wrong with installing a BMC 1.5 in a standard Narrowboat designed to operate on UK canals, I had one for decades and it gave sterling service. But,  and it is a big but, The BMC 1.5 is a marinized road vehicle engine and does not have enough power to propel even a small boat across the sea, for that you need, as already stated, a proper marine unit designed for sea going boats. Why are you unable to understand that?

 

I get the feeling the posters on this board are being played. 

 

Or thread, rather.

[TNLI]

6 minutes ago, StephenA said:

 

2 - we're running an old BMC 1.5 - with several 0s in the serial number.  Industrial flywheel. Been rebuilt at least twice and we have never had any problems with the HP fuel pump contaminating the oil and we've never changed the seals. Last rebuild was before the great floods when we had the boat at Upton

 

Its nothing to do with any of your reasons - it;s just an old engine and I'm not really sure it would survive being thrown around at sea. You talk about 45 degree tilt for a genset - I''m not sure what the max tilt for a BMC 1.5 is - how far can you tilt it before the oil lift stops picking up?  Of course I might be wrong but if I was going to replace our engine now I'd not be looking at another BMC 1.5 just because of the age.

 

As a complete aside the rebuild Calcutt did on our BMC was pretty crap.  Starline at Upton did a much better job (boat still starts first crank after 15 seconds of heaters in Winter even when its been standing for a few months).

 

 

Thanks, that's all very interesting. Not sure if all canal folks understand what gimbals do, as they can be used to get around oil feed related limits, which are normally 30 degrees for generators. Most marine diesels also list 30 degrees and a time limit, but most folks that motor sail shutdown the main engine once the wind picks up. Not seen a gimballed main engine, but it can be done and might be useful for some situations when you need to go as fast as possible, BUT the wind is not strong enough, so you need to keep the main engine running and the sails full. That will result in some kind of angle of dangle that could try and exceed 30 degrees if you are not sailing dead downwind.

 

Interesting remark on Calcutt, although I already know several local companies that can rebuild a BMC to a very high standard, although they are all very busy this summer. Sunseekers, Oyster yachts and the Royal Navy contract companies are all very busy, and that has a knock on effect that is resulting in a lack of interest in fitting an engine that needs different mounting plates to be fabricated and welded in position.

[David Schweizer]

15 hours ago, TNLI said:

Thanks, that's all very interesting. Not sure if all canal folks understand what gimbals do, as they can be used to get around oil feed related limits, which are normally 30 degrees for generators. Most marine diesels also list 30 degrees and a time limit, but most folks that motor sail shutdown the main engine once the wind picks up. Not seen a gimballed main engine, but it can be done and might be useful for some situations when you need to go as fast as possible, BUT the wind is not strong enough, so you need to keep the main engine running and the sails full. That will result in some kind of angle of dangle that could try and exceed 30 degrees if you are not sailing dead downwind.

 

Interesting remark on Calcutt, although I already know several local companies that can rebuild a BMC to a very high standard, although they are all very busy this summer. Sunseekers, Oyster yachts and the Royal Navy contract companies are all very busy, and that has a knock on effect that is resulting in a lack of interest in fitting an engine that needs different mounting plates to be fabricated and welded in position.

 

Your statements do seem to come over as pompous and arrogant.

[TNLI]

On 03/09/2021 at 21:58, David Schweizer said:

 

There is nothing wrong with installing a BMC 1.5 in a standard Narrowboat designed to operate on UK canals, I had one for decades and it gave sterling service. But,  and it is a big but, The BMC 1.5 is a marinized road vehicle engine and does not have enough power to propel even a small boat across the sea, for that you need, as already stated, a proper marine unit designed for sea going boats. Why are you unable to understand that?

OFF TOPIC REPLY

My last boat was a yacht, a Van Der Stadt 34, (Dutch professional steel hull, but homebuilt interior), it had a 3 cylinder Vetus M310 producing 27hp max. It was a little bit underpowered in terms of motoring into moderate seas. 

My new hull up project boat is based on a 27ft offshore alloy ships lifeboat that had a 4 cylinder BMC 1500 rated at around the 35HP max. Ships lifeboat engines must be capable of motoring into a moderate sea with a full load of survivors. The plan is to fit a hinged drop down A frame rig, with a Lanteen pole for light winds. 

35hp is enough for an offshore motor sailor of 27ft, but far too much for use on a canal, so I plan to fit a 10, (7 continuous) HP 48V go cart motor powered by a small air cooled diesel gen set in the forward survivors cabin. That should be just about enough to produce about 5HP from the main 3 bladed prop to reach the 4kt limit. If I was only going to use my lifeboat in the canals or rivers, I would fit a Yanmar 2GM, rated at around 18 to 20HP max. 

If you fit too big an engine as many canal boat owners seem to do, it will burn more fuel and get fouled up due to the use of low power settings.

 

Not too sure what you mean by proper marine unit, as most marine engines are based on diesel car or truck blocks, some of those advertised as marine engines, like the Yanmars are not as tough as older engines like the BMC in terms of surviving an overheat incident, or bad fuel. My first yacht has a Yanmar 2GM and it failed in a big way twice in 3 years, with one bad fuel incident trashing the injection pump and injector tips. No one in this forum seems to have suffered a seized HP pump, or had injector tips blown out.

Edited November 24, 2021 by TNLI

[TNLI]

BACK ON TOPIC

 

If you are thinking of buying a boat with an old BMC 1500, I would definitely not use it offshore without getting the crankshaft properly inspected, along with the torsional vibration damper. 

Inspecting crankshafts | 2012-10-17 | Auto Service Professional

 

Before the engine I'm working on is fitted I plan to have that check done, BUT I will be looking for a spare damper and crank shaft, just in case it's bad news. 

 

Diagnosing and resolving torsional vibration damper problems | Gates Europe (gatestechzone.com)

 

 

[john.k]

Aaargh ,yeah,but ye ave missed summat....ye must tap the compass to get a true bearing.....aaaargh.

[David Schweizer]

11 hours ago, TNLI said:

 < Snip >

 

Not too sure what you mean by proper marine unit, as most marine engines are based on diesel car or truck blocks, some of those advertised as marine engines, like the Yanmars are not as tough as older engines like the BMC in terms of surviving an overheat incident, or bad fuel. My first yacht has a Yanmar 2GM and it failed in a big way twice in 3 years, with one bad fuel incident trashing the injection pump and injector tips. No one in this forum seems to have suffered a seized HP pump, or had injector tips blown out.

 

You might just as well suggest that all diesel engines are basicly the same which they are. However, there are, and always have been, specially designed Marine engines which are not based upon road vehicle engines. Lister Petter and Russel Newbery come to mind, plus vintage/second hand units from numerous manufacturers.

 

 

Edited November 24, 2021 by David Schweizer

[TNLI]

4 hours ago, David Schweizer said:

 

You might just as well suggest that all diesel engines are basicly the same which they are. However, there are, and always have been, specially designed Marine engines which are not based upon road vehicle engines. Lister Petter and Russel Newbery come to mind, plus vintage/second hand units from numerous manufacturers.

 

 

Yes, I agree, many of the older generation low to moderate tolerance marine engines were designed and built specifically for marine applications, but I'm only interested in engines that you can find cheap parts for, and are not so heavy that they will compromise the ability of what is in effect my design, to surf with a following sea and a fair wind. Heavy engines like the BUKH series that I took a real good look at, are not good news for a motor sailor. The BMC engines are heavy, but the Bukh 36 (Similar HP), is seriously heavy and after a few quick sums, problematic in fore and aft C of G terms. I did take a very long look at a BUKH 24 reconditioned by Marine Enterprises, as it was OK in weight terms, better in long range economy terms, but the extra power and far lower price convinced the the Caribbean church group I'm associated with, that I should fit the same type of engine as was in my lifeboat when the previous owners sank it. 

 

PS: Any recommendations as regards which company can supply a new, or cheap used crank shaft ??  Also I will need to find a good used torsional damper, although it might be possible for me to inspect that before the local experts with their Magflux crack detector get busy binning or polishing up my old crank shaft. If Tony approves the pictures of that part, I might not need a spare, unless some clown sprays the wrong degreaser on it.

Edited November 24, 2021 by TNLI

[TNLI]

First of all, I have found a local company in Poole that recondition old crank shafts, and that job will be done before my pre abused BMC 1500 is installed. 

 

For the BMC nay sayers, I think this is intetresting:

 

bmc.pdf (nauticus.co.uk)

 

I would not that changing the oil every 50 hours is a bit OTT, unless the HP fuel pump or HG are contaminating the oil. The Yanmar figures of oil changes every 100 hours and oil filter changes every 200 hours are more realistic for an engine in good condition.

 

 

Edited January 2, 2022 by TNLI

[TNLI]

Does anyone geeky know how to print the document I gave a link to above, as it's a restricted access one ??

 

Also I would note that for some odd reason the oil dipstick, (It needs a hat conversion if you are in a drippy environment), did not reflect too well the actual oil condition it was in. There was some dark brown discoloration to the very bottom of the stick that looked interesting, BUT when I pumped the oil out it was in fact real nasty stuff, although that's normal when an engine is still running in.

[Tony Brooks]

1 hour ago, TNLI said:

Does anyone geeky know how to print the document I gave a link to above, as it's a restricted access one ??

 

 

If your web browser will not allow it, most will. Save it and open it in a  PDF  viewer application and most if not all give the print option. You will probably need a computer to do this unless your printer is wirelessly networked so your phone can talk to it.

[TNLI]

Now this is a good engine, BUT I seem to recall the TMP gearbox is not popular due to some type of weird cooling system ??

 

100 quid is cheap as a buy now option for good reasons I suspect, and no sign of a picture or link to the documents. The video clip is interesting:

 

 

BMC 1.5 marine Diesel engine Thornycroft T90 | eBay

 

This one shows the effects of what looks like coolant in the cylinders, namely sludge:

 

Edited January 17, 2022 by TNLI