Best engine to replace BMC

[cuthound]

I've not run Honeystreet on a real river yet unless you call the canalised Kennet from Aldermaston going west a river. No problems with overheating, and the Beta has proved to be reliable, probably approaching around 3000 hours on the clock now. One thing I've noticed is that it keeps its engine oil clearer than the BMC, still a nice golden colour on the dipstick.

Are you the DaveM that I gave a lift to some of the owners meetings?

A lot more maintenance than the average canal boat engine though. Plus, they're underpowered and a nightmare to steer on rivers, and oh boy do they go through the carrots!

You could always "give it some beans" ☺

[bizzard]

I have to, a small mini tractor. I used one for yanking out blackthorn bushes in preparation for laying out our sailing dinghy park. I had to finish the job with my L/Rover though which was much more powerful in low ratio.

[peterboat]

I have to, a small mini tractor. I used one for yanking out blackthorn bushes in preparation for laying out our sailing dinghy park. I had to finish the job with my L/Rover though which was much more powerful in low ratio.

David has the small toy nuffield tractor as well His Dad was into tractors before he died the Out buildings were full of them!!

[bizzard]

David has the small toy nuffield tractor as well His Dad was into tractors before he died the Out buildings were full of them!!

No fault with the engine though, just not as powerful as the L/Rover 2286cc petrol engine, nor was it as low geared as the L/Rover when in low ratio 1st gear or reverse.

[Neil2]

 

Define inefficient? Fuel consumption, or something else?

 

Our 1.8 always used to return consumption figures in the 1.0 to 1.5 litres per hour range, despite being run quite hard quite often. This seems much the same as people quote for Beta, Isuzus, Nannis etc.

 

Why do you beliee a 1.5 is a significantly different prospect from a 1.8? (Not that I'm sure we have yet been told what the OP's boat currently has, unless I have missed a post that says so).

 

To be clear, I probably would go the "non BMC" route in this share boat, but I do think many people rubbish the BMCs for a whole host of reasons that actually often don't stand close scrutiny.

 

With respect Alan I'm not casually "rubbishing" these engines without good reason or experience.

 

Ok pottering up and down narrow canals we all know that most engines return pretty much the same fuel consumption figures.

 

But having taken a BMC 1.8 all over the network my opinion is that the shortcomings of these units are exposed when you start asking them to do some real work. Ours was in a relatively light boat too. Put it this way - if you were to choose a modern diesel of equivalent cc you would expect it to provide enough grunt for pretty much any situation you might encounter on a narrowboat. I wouldn't place such trust in a BMC 1.8.

 

The popularity of these units (and the 1.5) stems from the fact that they are very tolerant of low speed running, and in the days when a lot of the time engines were running at just over tickover to keep batteries charged this characteristic was more important than out and out power. It's the reason why the engines though a dismal failure as automotive units found a new lease of life when leisure boating started to take off.

 

Ok maybe you could construct an argument that in the pure context of the canal network these engines are no more or less "efficient" than modern equivalents, but it wouldn't persuade me.

 

I draw a distinction with the 1.5 which to me is a completely different engine, it's a much sweeter unit. A bit like the old Morris Minor engines, though the 1098 unit on paper was the more powerful, the 948 was much more refined and just "suited" the car. In the same way BMC 1.5's do seem to suit a smallish boat somehow.

[davem399]

Are you the DaveM that I gave a lift to some of the owners meetings?

Yes Alan, that's me! Still using the boat, due on again at the beginning of October for an off-season week on the K and A.

[David Schweizer]

The BMC B series was as you say new in the 1950s but all these engine designs of the time were progressions and so have DNA so to speak from earlier designs. The closest was the 1200cc OHV used in the Austin Devon in 1947 which has origins in pre-war side valves. The diesel version in 1.5 form was built alongside the petrol in the 1950s but I think (not sure) the 1.8 diesel we know and love was a later conversion from the petrol engine in the 1970s for the Sherpa van.

 

I remember it well. I bought one for £5 in 1965, Ran it for a while until it was replaced with a Somerset ( bought for £8)

[alan_fincher]

I draw a distinction with the 1.5 which to me is a completely different engine, it's a much sweeter unit. A bit like the old Morris Minor engines, though the 1098 unit on paper was the more powerful, the 948 was much more refined and just "suited" the car. In the same way BMC 1.5's do seem to suit a smallish boat somehow.

 

Well we are veering enough off topic to maybe not help the original poster, (but I would still like to know which of the two engines they have).

 

I think the "to me" may be the key part of the above statement, as clearly the two units are not radically different in most peoples eyes. Yes the injection pump arrangements differ, (many suggesting that the 1.8 is better in this respect), and obviously the larger engine has a larger bore size, but surely that is about it?

 

The only downside I can see of the 1.8 over the 1.5 is that the increased bore size means there is less head gasket between adjacent cylinders, and hence a slightly increased chance of head gasket failure.

 

One of the main upsides of the 1.8 over the 1.5 seems to be parts availability. For example all 1.8s seem to use an easily obtained water pump, whereas several different types were used on the 1.5, some of which seem completely unavailable new, forcing people down the rebuild path. You are also, I believe far less likely to shear off the larger glow plugs used in all but the earliest 1.8 engines, if you need to remove them.

 

All things considered I would rather have a 1.8 than a 1.5 if I still had a boat with one in.

 

I have heard no evidence that even pushed hard a BMC will burn more fuel than a modern Japanese unit. Ours always seemed to return the kinds of numbers people quote for far more modern engines.

 

I remember it well. I bought one for £5 in 1965, Ran it for a while until it was replaced with a Somerset ( bought for £8)

 

"Hey, big spender!......."

[Peter Thornton]

Well we are veering enough off topic to maybe not help the original poster, (but I would still like to know which of the two engines they have."

Hi Alan, thanks very much for your contribution - we have a 1.8.

 

I think we're reaching the conclusion that another BMC would be a good choice if we could find the right person to rebuild it and if it was a one man boat. But exchange engines seem to be a lottery and we have 10 owners who use it fairly hard.

This is pushing us toward a replacement Japanese engine and it seems that Beta 38 or 43 might be the obvious choice. But there seem to be some cooling issues with a 43 so we'll have to take some advice on this.

 

Thanks to everyone who has contributed - it's been invaluable, and keep the comments coming, especially ref Beta 38 versus 43.

Edited August 13, 2016 by Peter Thornton

[alan_fincher]

Well I'm no expert on such matters, but I fail to see why a Beta 43 in normal operation would need to dissipate more heat through the cooling system that a Beta 38, unless it was actually being worked relatively hard to produce more power than would have been the case with the smaller engine.

 

On the other hand, of course, there isn't a great deal of point having that power available, if you can't use it.

 

Except, that cause overheating you would have to use it at high power for an extended period. Using more power briefly if you need to stop in a hurry, or get out of a tricky situation is unlikely to provoke problems unless you keep doing it.

 

Beta publish fairly good guidelines about minimum skin tank sizing and design, so seek this out and compare it to what you currently have.

The other consideration is whether your current prop will be a good enough match to the new engine's power and gearbox ratio. I guess it is probably more likely to be OK with the 38 than the 43, but you need to know what you have, and seek advice, I think. The extra power may not be much help if the prop is a poor match.

[bizzard]

To be safer as far as overheating goes, I'd go for the Kubota 38 or even a Mitsubishi 33. A bloke with a boat here also went for the 43 after an old lower powered Lister packed in, he has to watch his temp gauge all the time as it creeps up if he's got fairly high power on. Also take serious note of my ''post 17'' about alternators.

[Tony Brooks]

Remember Beta say 1 sq ft of skin tank external area for each 4 hp so a 43 would need just over 10 sq ft. A 38 just under 10 sq ft and similar for a BMC 1.8. Many inland boats get away with less than this and no overheating but as share boat that might want to do Torksy to Cromwell in one hit I would think that you should heed Beta's figures. They will hold good for all makes with a slight reduction in area for good direct injection engines.

[Peter Thornton]

One of our engineers said that these S Series Ownership boats are a little undercooled in their standard configurations and that there is limited airflow around the engine bay. Are there any S series boats on here?

I think Alan's right that the heat output will be the same for the same power output but of course a 43 will make more power, and if it's being flogged up a river ..........

Is it easy to fit an audible alarm to warn of overheating?

[bizzard]

One of our engineers said that these S Series Ownership boats are a little undercooled in their standard configurations and that there is limited airflow around the engine bay. Are there any S series boats on here?

I think Alan's right that the heat output will be the same for the same power output but of course a 43 will make more power, and if it's being flogged up a river ..........

Is it easy to fit an audible alarm to warn of overheating?

Being under cooled may be the case with the S boats when they were new, but now years on, probably won't be the case, the skin tank will probably be furred up a bit with limescale and rust by now. Also the hull on the outside of the skin tank may have quite a thickness of blacking on it by now, both will reduce the cooling effect.

[Peter Thornton]

Being under cooled may be the case with the S boats when they were new, but now years on, probably won't be the case, the skin tank will probably be furred up a bit with limescale and rust by now. Also the hull on the outside of the skin tank may have quite a thickness of blacking on it by now, both will reduce the cooling effect.

Not sure of the technical descriptions here but by "undercooled" I meant running too hot, I.e. Not being cooled enough. Surely what you describe would make this situation worse?

[cuthound]

One of our engineers said that these S Series Ownership boats are a little undercooled in their standard configurations and that there is limited airflow around the engine bay. Are there any S series boats on here?

I think Alan's right that the heat output will be the same for the same power output but of course a 43 will make more power, and if it's being flogged up a river ..........

Is it easy to fit an audible alarm to warn of overheating?

Ownerships first series of boats had names beginning with either "S" or "O", so I wouldn't attach any credence to that theory, particularly as most were Pat Buckle shells, but a few later ones were built by Graham Reeves.

 

The later ones, named after canalside villages, we're built mainly by Graham Reeves, with the latest few built in Poland by Hexagon.

 

To my knowledge Honeystreet (a Reeves hull) only suffered cooling issues in the latter days of her BMC engine installation (as well as poor fuel consumption). Both attributable to her worn engine, and in particular a very worn camshaft, abetted by many layers of blacking on the swims.

 

The skin tanks were left as original for the Beta 43 transplant.

 

One current owner of Honeystreet has testified that there are no cooling issues on canals and canalised rivers. Perhaps a current owner can confirm if this is the case against the flow on rivers?

Edited August 13, 2016 by cuthound

[bizzard]

Not sure of the technical descriptions here but by "undercooled" I meant running too hot, I.e. Not being cooled enough. Surely what you describe would make this situation worse?

Ah, quite right, I somehow read it as being over cooled. If under cooled even more important not to fit a more powerful engine.

[Theo]

Hope you don't mind the move. I though that I would move this.

 

Theo

[David Schweizer]

 

I remember it well. I bought one for £5 in 1965, Ran it for a while until it was replaced with a Somerset ( bought for £8)

"Hey, big spender!......."

 

You think that is cheap, my car prior to that was a 1939 Austin Seven Ruby which cost £2. Two later cars, a Humber Hawk and a Standard Vanguard were free!! Those were the days.

[Midnight]

One of our engineers said that these S Series Ownership boats are a little undercooled in their standard configurations and that there is limited airflow around the engine bay. Are there any S series boats on here?

I think Alan's right that the heat output will be the same for the same power output but of course a 43 will make more power, and if it's being flogged up a river ..........

Is it easy to fit an audible alarm to warn of overheating?

 

The Beta 43 deluxe panel I have has both a audible warning and a temp gauge - I think you wont have any problems with overheating if you have an additional skin tank fitted.

[churchward]

 

You think that is cheap, my car prior to that was a 1939 Austin Seven Ruby which cost £2. Two later cars, a Humber Hawk and a Standard Vanguard were free!! Those were the days.

Nice!

 

My chum's father as a kid had a Triumph renown and a 1950s Humber Super snipe, lovely big black things used for wedding cars etc. We used to get a few coppers for giving them a wash and got to play in them.

 

I think the cheapest car I remember was a Victor 101 bought with a mate for £25. It was a big heavy thing and rather beat mechanically. It had a 3 speed column change that if you waggled it about enough eventually you would get a gear. Which gear was a bit of a lottery!

[Tony Dunkley]

We're hoping that the work can be done over the Winter period, so the time taken to replace isn't a big issue.

The cost is relevant, although it's divided by ten and reliability is also crucial. Our current breakdown has wrecked one Summer holiday.

 

 

I have got a low mileage/hours, ex-vehicle 1.8 bare engine which I've had in stock for quite some time. It's a BLMC 'Gold Seal' factory exchange engine that came out of an MOT failure van.

If your engine is repairable, then a straight exchange with your present one would get you going again with minimal delay.

[ditchcrawler]

Maybe a read of this http://noproblem.org.uk/blog/so-here-we-go-first-though-the-cooling-system/and how Biggles of this parish fixed it

[Bee]

 

You think that is cheap, my car prior to that was a 1939 Austin Seven Ruby which cost £2. Two later cars, a Humber Hawk and a Standard Vanguard were free!! Those were the days

Someone gave me an Allegro only a few years ago, reckon that trumps a Humber Hawk!

[churchward]

Someone gave me an Allegro only a few years ago, reckon that trumps a Humber Hawk!

You were done! I am surprised the person didn't pay you to take it away.