BMC Captain Diesel

[Guest]

I have seen a boat with a BMC 1500 Diesel engine. The brokers details rates the engine at 35hp. I recon this must be a road engine marinised? If this is the case, at 35hp, it wouldnt propel much of a vehicle!. So. Are marine engines rated differently, or has it been detuned. If the latter, how?

 

[ccscott49]

The BMC 1500 diesel wasn't much of a diesel, its not until you start getting to turbo a 1500, that it starts to produce power! The 1500 wouldn't pull the skin off a rice pudding in a van, but fine for a boat! When you think that most 1500 petrol engines of that era only produced about 60 HP, its not that bad.

 

[Guest]

The engine in the boat is not turbocharged of course. in a 33 foot boat would it provide the power required for comfortable manouvering?

 

[toad]

Just out of interest the BMC/Leyland 1500 diesel was rated at 37(DIN)BHP at 3500 rpm on road vehicles.

 

[ccscott49]

Simple answer, Yes! 35 hp is plenty of power for a 33' boat, sail or power. They are a pretty reliable engine, just make sure all the marinising bits are in good nick, I find its advantageous with a not known engine, to pull a few bits and pieces and check their condition, all it costs is a bit of time and a few gaskets. Gives you a chance to replace any really rusty nuts and bolts with stainless at the same time, it's just a suggestion, but I like to know whats going on in the engine room of my boats!

 

[colin_jones]

Thee were literally 1000s of BMCs of various cc ratings used in boats (1.5 - 2.2 - 2.5) and they are still strong in existence and usually very relaible. They seem to go on forever. I used to run a passenger boat out of Swanage with a 1.5, it was fine in the late 50s and is still going today. Many canal and hire boats use the captain - as did London taxis, vans and many buses used the larger model.

If you get involved and need the address of a couple of firms still servicing these engines and holding spares, either give me a PM or post here on the board, where the topic has been previously aired

 

[Guest]

The BMC 1.5 is a wonderful engine and shoud be perfectly up to a 33' boat. We used to run a fleet of narrowboats powered by these engines and they gave us very little trouble and ran in our hands for up to 22,000 hours without any major work being needed. Main thing to watch is that you must draw the heater plugs regularly and clean them: this aids starting and also prevents coke build-ups seizing the heater plugs in place. Efficient heater plugs are essential for cold weather starting.

 

[Jcorstorphine]

Engine started off as a petrol 1498 cc for the Austin Cambridge, Morris Oxford and then modified by fitting a diesel head for use in these cars and the Post Office J4 vans. Was reputed to be used in London taxis but i am sure that was the 2.2 engine. BMC brought it out as a Marine diesel in the early 60s under the name of the BMC Captain. Later called the Tempest Captain. Great engine, simple to work on, no frills, runs until the pistons are square so long as glow plugs kept ok.

Change the oil and filer kep it clean and it will run for ever

 

[oldharry]

Agree with the other posts - the old BMC 1.5 is a first class engine.

Beware however of spurious Brokers claims about power: Unless there is at least 2:1 reduction gearbox, the highest viable propellor speed is around 1800 - 2000 RPM, at which speed the BMC only develops around 15hp, which for a 33 footer is a bit on the low side. To attain a decent power output any engine must be able to develop something approaching its designed top speed, by gearing down. Above around 2000 rpm, a prop on a displacement boat will start cavitating and loses almost all its propulsive power, by creating a near vacuum on the blade surfaces. The blades before long become severely pitted and unuseable at these speeds.

My old BMC with a direct drive (1:1 gearbox) developed around 1600rpm. Fitting a smaller prop allowed the engine speed to increase, but efficiency was falling away so it made very little actual difference.

High speed propellors on planing craft are a different kettle of fish altogether, where the pitch is set to allow the water to remain in close contact with the blades at high speed - but losing hugely on low speed efficiency as a pay-off!

 

[vanbinst]

I have such an engine on a Colvic 31 motorsailer. It is working very well since 1976. I bought the boat in 1987 and had to replace the heat exchanger with a Bowman one. The engine is linked to a Newage (Coventry) gearbox. At the moment, I am unable to find replacement oil filters for this gearbox. Can anyone tell me where I could be able to find such filters.

 

[Nomadkarl]

The BMC 1500 diesel wasn't much of a diesel, its not until you start getting to turbo a 1500, that it starts to produce power! The 1500 wouldn't pull the skin off a rice pudding in a van, but fine for a boat! When you think that most 1500 petrol engines of that era only produced about 60 HP, its not that bad.

Can anyone give any advice on main things to watch out for on a BCM1500 as I have deposited money on a boat with one and tbh know nothing about engines. Boats and electrics yes. Mechanics no! It was rebuilt 2004 and had regular services. Water pump is being changed I'm told and other from that seems fine. Just wondered if there are any main areas of stress or ware and tare that I need to focus on? Thanks you.

 

[Nomadkarl]

Can anyone give any advice on main things to watch out for on a BCM1500 as I have deposited money on a boat with one and tbh know nothing about engines. Boats and electrics yes. Mechanics no! It was rebuilt 2004 and had regular services. Water pump is being changed I'm told and other from that seems fine. Just wondered if there are any main areas of stress or ware and tare that I need to focus on? Thanks you.

BMC! Fat thumbs and predictive! Haha

 

[Graham_Wright]

"Guest" and "Guest" seem to have changed sides?

Vide #1 and #7.

If possible, do a compression test. It is relatively non invasive and tells you a lot and search this forum.

 

[tillergirl]

Tiller Girl originally had a BMC 1.5 diesel. It ran and ran. After I sold it, it went into another boat. TG was 8 tons of wood and the engine was fine. the prop was a bit naff - too fine pitched. Stopping using reverse used to be a bit pointless for a while. I only sold the boat because of the vibration; she was rigidly fixed. You could play a tune with the kettle by changing the revs. And if we wanted to all the VHF, we had to stop down to tick over. The gearbox was quite unusually. There was a gearbox, clutch assembly and a reduction box. The yard reckoned the box, reduction and clutch assembly was heavier than the engine itself! The gear level had three progressive stages - one, moving the level part way disengaged the clutch, then two, engaged gear, then three, dropped the clutch. So it too quickly with revs up and you could play a tune! But the engine was absolutely great. It did need attention for glow plugs,

 

[Rappey]

The BMC 1.5 Diesel engine was probably the most widely used engine within the marine industry throughout the 1960'sand 70's. Its ability to withstand abuse, abundant and cheap spares parts made it the most favoured engine in the hire boat industry. Many companies marinised the engine and sold it as a ‘turn key’ ready to run kit for boat installation. Thorneycroft, CT marine, Tempest and Newage all offered theengine marinised and ready to run.
Perkins offered the 4.107 but this was bigger, more expensiveand technically more advanced, which meant it was more difficult to repair and spare parts were very expensive. With this in mind most of the hire fleet operators fitted 1.5 BMC engines as standard.
I have one and have read many things over the past 30 yrs..

The Good Points
1. Excellent reliability. Easy to find spare parts, relatively cheap and easy to maintain.
2. Economical diesel fuel consumption burning less than a gallon per hour working under normal loads.
3. Good access to most parts of the engine including the diesel injector pump
4. In good condition, these engines are almost as smooth as any ‘modern’ diesel engine of today
.5. Standard Lucas automotive starter motor and alternator can be used.

The bad points.
They can twist the crank if overheated.
They like clean fuel
oil leaks..
It really is that simple !

Asap supplies and many other retailers sell most of the parts off the shelf but the best part is the price.
I treated mine to a new duplex cam chain, tensioner and gasket - £18 (retail) New fuel lift pump £24 .. The parts are very cheap when rarely needed.
A bmc can be professionally rebuilt by specialist companies such as calcutt for less than half the price for a new diesel engine.
One similar business (i can remember who it was) had a statement something like - If we had to re engine one of our hire boats with a new beta, nani or recon bmc we would chose the bmc every time as 25 years down the road when the new ones have had it the bmc will still be going.

Mine was born in 1965, did many hundreds of thousands of miles in a j2 morris van. Around 1980 it was reconditioned and fitted to my current boat.
4 Years later the boat was nearly wrecked when dismasted crossing biscay. She lay in a boatyard for 6 years and had a foot of rainwater inside..
I aquired the boat and had to dismantle the engine as it was seized, probably from all the damp?
I beat the pistons out with a block of wood, picked the seized rings out of the pistons , lightly sanded the bores, bought new big and small end bearings and new rings, got the injectors and pump reconditioned - and it started and for for much less than £500.
27 years later it is still running..

If you can give it glow plugs for 20 secs and it starts then there is no reason why it should be problematic?

 

[Rappey]

From what ive learnt and the original workshop manual -
Maximum bhp for intermittent use 39 @3500 rpm.
Maximum BHP Continuous 30 at 3000 rpm

The marinised versions were restricted to 3000 rpm but the ones like mine can supposedly hit their max rpm at 4400 ?
Im around 12 tons and maximum hull speed is reached way before the engine maxes out.

 

[Jim@sea]

I have seen a boat with a BMC 1500 Diesel engine. The brokers details rates the engine at 35hp. I recon this must be a road engine marinised? If this is the case, at 35hp, it wouldnt propel much of a vehicle!. So. Are marine engines rated differently, or has it been detuned. If the latter, how?

Going back to the late 1960's and early 1970's I used to sell the vehicles which these engines were fitted in, mainly Austin J4 Vans. Compared to today these engines are krap.. The Austin J4 Van was a small van the engine was located between the driver and passenger seats. It was noisy. In those days van drivers expected to be only able to reach 50 mph. Some of the vans I was buying to sell had done over 300,000 miles. Very reliable as in those days it was normal to do an oil and filter change every 6.000 miles. (not like today) The vans I was buying to sell had the original engine in, and they were worn out.
Nightmare to start in the morning unless you used Easy Start, Every van I sold I gave the customer a free tin of Easy Start and said "You might need this"
The bigger BMC engines, 2500cc were fitted in the larger Austin J2 Vans. I bought a Colvic Watson with one of these engines , wrongly assuming that I could get engine spares. I mistakenly thought that as the BMC 1800 petrol engine was fitted into the MGB where you can buy reconditioned engines, water pumps etc that the same availability would be for the BMC diesel. It isent.

 

[jneale]

I had my 1960s BMC captain for 15 years and did 15000 miles before having to sell it . Everything in the above articles is true. It is a lovely smooth 4 cylinder engine. Runs quiet at about 2500rpm Mine burnt very little oil but dripped a bit in the bilge. It used to be hard to start despite using 20 seconds of heater first and flooding the engine, but eventually was told to advance the timing a midge - and after that it started easily from cold . Possibly was a worn timing chain.

 

[TNLI]

Anyone got a plan of the engine mounts and drive shaft flange positions, as I'm going to install a Bukh 24 onto the same beams and mounts as a BMC 1500, so I will need to make 4 adapter plates for the new mounts.
The old BMC was sold as it was far too badly damaged to be rebuilt.

 

[PCUK]

My 14 ton steel cruiser had a BMC 1.5 as a wing engine and could achieve 5.5 knots with a folding 3 blade prop'.