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BMC Engine spewing white smoke...


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Look, BMC engines are not exactly Swiss watches, but they are robust. My BMC got some serious boiling when I lent it out and the raw water intake got blocked but it's been none the worse for the experience. Fill it with water and check the oil, then take it out and Phylis it for a while 'till it's good and hot. If the levels are still good and the oil isn't contaminated it will most likely be fine. Get a quote for a head skim and argue it off the price.

The size is not specified!

I've come across quite a few BMC 1.5 heads that have cracked, but then there seems to be quite a few 1.8's with 1.5 heads on, so thats probably meaningless.

Anyhoo the thing didn't cease and they usually do as soon as they get really hot!

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The size is not specified!

I know you can't pay too much credence to brokers details, (particularly this broker, I think), but it's stated as 36HP.

 

That seems to be the oft quoted number for the 1800 engine, and the 1500 is usually quoted at less, and the 2200 and 2500 considerably more.

 

I have assumed in the discussions that this was a 1.8, but who knows!

 

FWIW our 1.8 boiled on the last day of it's 3 week, 400 mile trip, (reasons unknown), and initially I feared the worst. However after a long cooling off period we refilled it, (lots of water :lol: ), and it performed faultlessly for the rest of the day. Obviously I don't know that we haven't damaged it, but the initial prognosis is looking very favourable.

 

However, isn't the 1800 usually reckoned to be more easily damaged, because the way the extra capacity in each bore was achieved was by a larger diameter, and hence less metal, (and less gasket) between each 'pot' ?

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hello everyone,im one of the berks that went to see this boat with a built in engine room sauna,im wondering if any of you knowledgable people have any opinion on whether the engine would be knackered after mine and kevs little jaunt

 

 

thanks

 

 

I am going to comment on more than this post.

 

I have already told Dave that if he does a high speed run to Caversham lock, down to Sonning then if there is no sign of overheating or excess smoke when he gets back the engine is probably fine. Sir Nibble has basically said the same thing.

 

I suspect the black cylinder head is mainly rubber dust, not blackened paint.

 

I must have had hundreds of 1.5s & 2.2s brew up when I was on the hire fleet but the only one which resulted in engine damage as far as I can remember was one where the hirer kept running it until the engine stopped as a black smoking lump. BMCs seem very robust.

 

As long as there is sufficient water in the engine to cover the head/block joint and the valve seats (the bottom of the head water jacket) the parts of the head that get damaged will still only be at about 100c and no damage is likely unless some clown fills it with cold water. We know the engine was allowed to cool naturally but do not know how much water was boiled away but as a little water makes a hell of a lot of steam my feeling is the engine is probably OK.

 

Of far more concern to me is the fact that I was unable to check the charging of the 12/24 volt systems and this is where I suspect money may have to be spent.

 

Whatever I may think to myself I can not risk giving a firm opinion because if I did and I was proved to be wrong my good name is at stake (If I have one) and who wants a course delivered by an idiot?

 

I suspect that even if Dave paid for an engine condition report it would be full of get out phrases as to be little more use than my report.

 

Seeing what was said in the thread about the Harborough boat it would seem that if the engine and charging system are OK this boat, after a bit of hard work on the pant front, could turn out to be good value but there is always that possibility it turns out to be a dog.

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Just an extra aside. Bear with me.

A few years ago, this bloke arrives with a Paris Rhone 12V 60A alternator and wants it replaced 'cos it don't work. A day later he's back 'cos the replacement don't work. Now since the replacement was rebuilt under my own fair hand, I wanted to find out what was happening and attended the boat. It was 24V. The engine electrics were all 12V but the system had recently been overhauled and due to a communication cock up was wired 24V instead of the original 12. Not surprisingly the glow plugs were shot but the starter was so enthusiastic that the motor still went. I installed a 12V engine battery and replaced the glow plugs, fitted a 24V alternator and then fitted a 24-12V converter to charge the battery. Output was about 14V so thats all right. I had to fit a relay in the supply to the dropper so that it was only active with the motor running, and led cables out to replace the internal fuses with external ones so that they could be replaced if the engine battery was run down to the point where the current demand exceeded the dropper's rated output. It was a bit of seat of the pants engineering a typical "well if I wanted to get there I wouldn't start from here" situation, but it worked and continues to do so.

Sounds to me that this is what has been done to this boat and it's the first time I have heard of anyone else taking this route out of a silly situation.

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Just an extra aside. Bear with me.

A few years ago, this bloke arrives with a Paris Rhone 12V 60A alternator and wants it replaced 'cos it don't work. A day later he's back 'cos the replacement don't work. Now since the replacement was rebuilt under my own fair hand, I wanted to find out what was happening and attended the boat. It was 24V. The engine electrics were all 12V but the system had recently been overhauled and due to a communication cock up was wired 24V instead of the original 12. Not surprisingly the glow plugs were shot but the starter was so enthusiastic that the motor still went. I installed a 12V engine battery and replaced the glow plugs, fitted a 24V alternator and then fitted a 24-12V converter to charge the battery. Output was about 14V so thats all right. I had to fit a relay in the supply to the dropper so that it was only active with the motor running, and led cables out to replace the internal fuses with external ones so that they could be replaced if the engine battery was run down to the point where the current demand exceeded the dropper's rated output. It was a bit of seat of the pants engineering a typical "well if I wanted to get there I wouldn't start from here" situation, but it worked and continues to do so.

Sounds to me that this is what has been done to this boat and it's the first time I have heard of anyone else taking this route out of a silly situation.

 

 

I think you are right and looking at the "dropper box" I do not think it will be rated at more than about 10 amps so I am suspicious of the effectiveness. Still if it is 24 to 12, at least the starting battery will not require the sort of charge a domestic bank may well.

 

However the box says inverter and 13.6V - 24V so I have a horrible feeling it may be 12 to 24. I am just sorry that I will not be around to have another look when it is supposed to be working.

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