Jump to content

Have BMC engines "had their day"


Alan de Enfield

Featured Posts

3 hours ago, Tracy D'arth said:

Obviously cracked blocks are now scrap and sleeving over bored ones is too expensive, maximum over bore is 60 thou.

 

 

I think that's the state of the bores in ours. Starline basically said it was the last rebuild for the engine.

Link to comment
Share on other sites

16 hours ago, Tracy D'arth said:

1.8D suffers from premature timing chain and tensioner wear, its too long. Replace the crank sprocket and even the cam sprocket along with the chain, slipper and tensioner if there is any hooking of teeth.  MGB sprockets fit.

 

 

Personally I'd run away from a BMC 1.8 because of the timing mechanism. I think I've probably averaged a tensioner failure per week's cruising. Not a fan.

Link to comment
Share on other sites

8 minutes ago, phantom_iv said:

 

Personally I'd run away from a BMC 1.8 because of the timing mechanism. I think I've probably averaged a tensioner failure per week's cruising. Not a fan.

Possibly injection timing a bit over advanced, makes em kick.

Link to comment
Share on other sites

The fixers don't change the sprockets, the teeth get hook shaped and trash the chain to death. The tensioner is a good part, same as the twin cam Jaguar bits but if they don't do the job properly it gets chewed up.

TD'

Link to comment
Share on other sites

15 minutes ago, Tracy D'arth said:

The fixers don't change the sprockets, the teeth get hook shaped and trash the chain to death. The tensioner is a good part, same as the twin cam Jaguar bits but if they don't do the job properly it gets chewed up.

TD'

 

Having seen a couple of failed tensioners and compared a chain post-failure to a new chain, I wouldn't say it looked like the chain was trashed. But then I'm sure there are many possible failure modes.

 

On the other hand, I am quite impressed by how many timing failures it takes to trash a BMC ?

 

Link to comment
Share on other sites

The way to check the chain is to fold it in two, hold one end, hold it horizontal so that it does not fold, ie. with the fishplates top and bottom.

Look at how much it droops compared with a new one. That is all play due to wear in the pins and plates which causes it to oscillate sideways when running. 

TD'

Link to comment
Share on other sites

35 minutes ago, Tracy D'arth said:

The way to check the chain is to fold it in two, hold one end, hold it horizontal so that it does not fold, ie. with the fishplates top and bottom.

Look at how much it droops compared with a new one. That is all play due to wear in the pins and plates which causes it to oscillate sideways when running. 

TD'

The way I was taught to check my motorcycle chains was similar, but :

 

Lay the chain out on a flat surface with the 'plates' on the 'sides'(not lying on it), then take one end and see how close you could bend it towards the other end - making a U shape.

Pretty much any movement meant the chain was kerackered.

Link to comment
Share on other sites

1 hour ago, Alan de Enfield said:

The way I was taught to check my motorcycle chains was similar, but :

 

Lay the chain out on a flat surface with the 'plates' on the 'sides'(not lying on it), then take one end and see how close you could bend it towards the other end - making a U shape.

Pretty much any movement meant the chain was kerackered.

Same thing really but I bet your bike chains were a lot longer! And larger pitch single rollers.

The timing chains are duplex on diesels.

TD'

 

 

Edited by Tracy D'arth
Link to comment
Share on other sites

6 minutes ago, Tony Brooks said:

Triplex on some - BMC 2.2

FX4 taxi engine, not many in boats and not an engine I have had much to do with.

BMC produced a bewildering range of different small diesel engines, there was no relations between taxi, van car and Landrover.

Same in the petrol car range, A30, A35,  Minors, Minis, 1100, 1300 even Cooper S, many different engines.

Link to comment
Share on other sites

23 hours ago, dmr said:

I am currently trying to learn about boat engine life expectancy. It looks like 16000 is really god for a lightly loaded diesel. What are you doing so right? Do you do quite a bit of high load river boating? Our engine (not a BMC) is starting to show some blowby and oil consumption after 12000 hours. Due to lockdown we have done a lot of battery charging and no full load river cruising this year. Maybe a good thrash will sort it out.  12,000 to 15,000 hours is often quoted as a reasonable life before fixing rings/bores.

 

.................Dave

 

The Turkish built BMC1.8 in my last shareboat mansged 13,500 hours before being replaced by a Beta43. Main problem was worn camshaft and excessive crsnkcase pressure from worn bores.

Link to comment
Share on other sites

1 minute ago, cuthound said:

 

The Turkish built BMC1.8 in my last shareboat mansged 13,500 hours before being replaced by a Beta43. Main problem was worn camshaft and excessive crsnkcase pressure from worn bores.

Its hard to separate facts from optimism/marketing on the www but 12 to 15,000 hours appears to be the consensus for industrial/heavy duty type diesels, with light loading causing significant bore problems, so this fits in well with your engine. 12 to 15k is the time to the first big overhaul rather than the ultimate life of the engine.

Quite a lot more (20,000+) is possible in ideal conditions but probably not in narrowboats due to the light loading issue.

 

I note that some Gardner info suggests their engines last much longer but head removal at 5000 hours and crank regrinds at 20,000 are regarded as routine servicing ? 

 

............Dave

Link to comment
Share on other sites

10 hours ago, dmr said:

Its hard to separate facts from optimism/marketing on the www but 12 to 15,000 hours appears to be the consensus for industrial/heavy duty type diesels, with light loading causing significant bore problems, so this fits in well with your engine. 12 to 15k is the time to the first big overhaul rather than the ultimate life of the engine.

Quite a lot more (20,000+) is possible in ideal conditions but probably not in narrowboats due to the light loading issue.

 

I note that some Gardner info suggests their engines last much longer but head removal at 5000 hours and crank regrinds at 20,000 are regarded as routine servicing ? 

 

............Dave

 

Yes, that fits in with my experience at BT where I ended up as Head of Power and Cooling Technical Services, responsible for over 6,500 diesel engines standby generators ranging from 10kVA sets to 3MVA behemoths based on huge marine engines.

 

Most of their engines were lightly loaded and run for only a few hours per year, but some did run for extended periods and clocked up significant hours.

 

In my experience rebuilt smaller automotive based engines don't last as long between rebuilds as those based on industrial engines do.

 

It was because of that that the engine in the shareboat was replaced rather than rebuilt - cheaper in the long run given it was clocking up 1200 per year. That and the difficulty in finding good engine rebuilders these days.

Link to comment
Share on other sites

32 minutes ago, cuthound said:

 

Yes, that fits in with my experience at BT where I ended up as Head of Power and Cooling Technical Services, responsible for over 6,500 diesel engines standby generators ranging from 10kVA sets to 3MVA behemoths based on huge marine engines.

 

Most of their engines were lightly loaded and run for only a few hours per year, but some did run for extended periods and clocked up significant hours.

 

 

That's interesting. We have here  an ex GPO genset  88kVa, originally from an exchange . The engine is a Dorman 8LB  straight 8 diesel, runs to 100HP at 1000rpm for 50Hz. When we got it , around 1978, it had 400 hours on the clock. It had very little use after that , supplying 3ph 415v  when needed until we got a 3ph shore supply. At the time I was told that Dorman only ever  made 3 of the 8LBs  as there was a problem with the long crankshaft waggling about. Plenty of the lesser cylindered LBs were made. Do you have any experience of the 8LB?

Link to comment
Share on other sites

7 minutes ago, billh said:

That's interesting. We have here  an ex GPO genset  88kVa, originally from an exchange . The engine is a Dorman 8LB  straight 8 diesel, runs to 100HP at 1000rpm for 50Hz. When we got it , around 1978, it had 400 hours on the clock. It had very little use after that , supplying 3ph 415v  when needed until we got a 3ph shore supply. At the time I was told that Dorman only ever  made 3 of the 8LBs  as there was a problem with the long crankshaft waggling about. Plenty of the lesser cylindered LBs were made. Do you have any experience of the 8LB?

 

Unfortuneately not, I recall BT  had a few 4 LB's and 6LB's but I don't remember and 8LB's.

 

 

Edited by cuthound
Spillung
Link to comment
Share on other sites

15 minutes ago, billh said:

That's interesting. We have here  an ex GPO genset  88kVa, originally from an exchange . The engine is a Dorman 8LB  straight 8 diesel, runs to 100HP at 1000rpm for 50Hz. When we got it , around 1978, it had 400 hours on the clock. It had very little use after that , supplying 3ph 415v  when needed until we got a 3ph shore supply. At the time I was told that Dorman only ever  made 3 of the 8LBs  as there was a problem with the long crankshaft waggling about. Plenty of the lesser cylindered LBs were made. Do you have any experience of the 8LB?

The LB is an old engine so would have been designed in the days when experience and over engineering were used rather than full computer modelling. Making engines longer and longer does have potential for crank problems, a couple of automotive companies have come a bit unstuck doing the same. You can get unexpected issues with the firing order exciting crank resonances.

 

.................Dave

Link to comment
Share on other sites

We have a BMC 1.8 on our share boat. Experience is that they like regular oil changes, a good well maintained cooling system (ours has an expansion tank which seemed to solve previous problems) and sympathetic use. Ours has given very little trouble since we sorted out these three issues.

Link to comment
Share on other sites

Did BMC ever supply 1.5 diesels direct for boat engines.They were fitted to the J2 van,the Leyland 154 tractor and the Morris Oxford hire car(This had a finned alloy sump). Thorneycroft marinised the engine(I think they may have had connection with Leyland at some point).Nuffield used to sell marinised version of their car engines,but I dont think Leyland did. I have always assumed that the basis for the 1.5 diesel was the petrol B series.

Link to comment
Share on other sites

22 minutes ago, nebulae said:

Did BMC ever supply 1.5 diesels direct for boat engines.They were fitted to the J2 van,the Leyland 154 tractor and the Morris Oxford hire car(This had a finned alloy sump). Thorneycroft marinised the engine(I think they may have had connection with Leyland at some point).Nuffield used to sell marinised version of their car engines,but I dont think Leyland did. I have always assumed that the basis for the 1.5 diesel was the petrol B series.

Not that I know of. I would like to be proved wrong.

There have been a few conversions, Tempest Marine, Thorneycroft, Calcutt Boats. Even some labeled Newage who are PRM gearbox makers.

The B series petrol engines were designed in 1944, the diesel came a lot later. Although there are some similarities there is very little that is the same, the block and head are totally different, crank, cam, pistons all different.

The cam follower covers, thermostat cover and one type of water pump are the same! That's about it I think.

BMC, Leyland and Nuffield are renown for making many different units that could have been a common design but weren't.

Edited by Tracy D'arth
Link to comment
Share on other sites

1 hour ago, Tracy D'arth said:

Not that I know of. I would like to be proved wrong.

There have been a few conversions, Tempest Marine, Thorneycroft, Calcutt Boats. Even some labeled Newage who are PRM gearbox makers.

The B series petrol engines were designed in 1944, the diesel came a lot later. Although there are some similarities there is very little that is the same, the block and head are totally different, crank, cam, pistons all different.

The cam follower covers, thermostat cover and one type of water pump are the same! That's about it I think.

BMC, Leyland and Nuffield are renown for making many different units that could have been a common design but weren't.

Any idea about this BMC 1.5D? 

 

978774691_IMG_20200728_2356592.jpg.b50ca01d4734270e9f7e1a15f42a1c88.jpg1311015085_IMG_20200728_2355042.jpg.f3c39be308bc358f389eaedc77e10f85.jpg

 

The other one is similar but the riveted plate on the rocker cover is painted red (port side engine). They both say BOW". Other one is 729 so consecutive numbering. 

 

I was wondering if BOW meant something. I know Bowman heat exchangers but it's on the rocker cover. The power units have PRM delta 2:1 gearboxes with counter rotating props. Obviously these boxes work both ways so that's not a technical point as such. 

 

Serial numbers of the engines themselves are 26 apart so similar age units. 

 

I'd love to know what happened here, 35 years ago when the bloke "Tombstone Ted" made this boat :)

 

Edit the other one but the lightbulb on that side of engine room has blown so photos not as good plus the paint over the serial number. 

 

790520719_IMG_20200728_2357262.jpg.2591910217cfa38ceb931ad6370ebba9.jpg1433038479_IMG_20200728_2355262.jpg.515115cd640a325475fd27ae82d370d9.jpg

Edited by magnetman
Link to comment
Share on other sites

10 hours ago, nebulae said:

Did BMC ever supply 1.5 diesels direct for boat engines.They were fitted to the J2 van,the Leyland 154 tractor and the Morris Oxford hire car(This had a finned alloy sump). Thorneycroft marinised the engine(I think they may have had connection with Leyland at some point).Nuffield used to sell marinised version of their car engines,but I dont think Leyland did. I have always assumed that the basis for the 1.5 diesel was the petrol B series.

As Leyland was just a truck maker when the 1.5 came into service they never marnised the engine. It came in under Austin-Morris that was  essentially the Nuffield group. Then it was branded  BMC. As far as I know Newage were the BMC approved marinisers at that time. Then I think Newage went pop and Tempest took over. There was no difference between the Newage and Tempest marinisations. Essentially there were only two volume makes of diesels in this size, Perkins and BMC with BMC being highly successful so more and more individuals and companies started to marinise these engines. That's where Thorneycrof and JG Meaks come in and I know a lot of others. Meaks had their own flywheel housings cast and their own exhaust manifold. Others bought them in from Polar or Bowman and Tempest. We can add AMC to the list of marinisers I know about but there are more with one casting their own timing cover and other mounting the raw water pump on the timing cover so no secondary drive belt was required. I am  sure there was an operation marinisisng them, on the Broads. Add to that the Freds in sheds marinising their open ex vehicle engines.

 

In the 70s I  went for a job in a company making all sorts of agricultural/industrial equipment powered by 1.5s and they had racks of them direct form the factory that hey added the equipment needed for their specific applications. BMC have produced agricultural and industrial base engines with subtle differences hence the variety of engine water pumps, the availability of a mechanical rev counter  take off and I think the rear main design. When I was on the tools you could come across all types in boats

 

I am sure the reason we get more and more 1.5s causing problems is a combination of sheer numbers in use and the age of them plus the inability of so many people now a days to look after them adequately.

 

 The success of the 1.5 was such that  Ford dieselfied one of their 1500 OHV engines but it was never as widely used as the BMC. I suspect the development of the CAV DPA pump had as lot to do with the ability to convert petrol engines to diesel. BMC even dieslefied the 998 cc A series engine and I believe a hire fleet in Wales used them. It was intended for a Nuffield horticultural tractor. Until around 1960 if you wanted a small diesel you had to accept a single, two or three cylinder like Listers and the Perkins P3.

 

 

Edited to add: I understand that PRM stands for Percy Riley Motors so that would indicate that the makers of PRM boxes had their roots in the Nuffield Group so it would be sensible to use the Newage/PRM company to marinise the base engines because they already had a suitable marine gearbox.

Edited by Tony Brooks
  • Greenie 4
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.