Why did British Leyland fail?

[windrush]

ramone:
I heard they were plague by oil leaks but could hold their own on the road H.Baker at Bradford ran some and they were impressed with the mpg but then again they were 290Ls on motorway work which is a totally different ball game to your work i would expect . I had a 320 Gardner and loved it , again they were supposed to be bad for oil leaks and mine was never a problem , H.Bakers had some and they eventually retuned them to 350 bhp because they were sluggish mine was anything but

Aye Ramone, different work. We probably got 6-7 mpg from them. We had no trouble with oil leaks but some had liner problems, mine was totally worn out after ten years (when you started it from cold oil poured out of the exhaust!) so they put an engine in from a scrapyard which was even worse than the old one! Then they bought me a nice new truck.

We seem to be going round in circles with this thread, nobody will have the REAL answer now why it all went downhill but there are a few interesting theories being aired. I was never really a Leyland man, the old BMC and Leyland Redline commercial range was my only dealings with them, but they certainly served the industry well over the years and it was a sad day when it all got knocked in the head.

Pete.

[kr79]

cav551:

Carryfast:
[
Unfortunately there’s no way to ‘look after the customer’ in the case of a basic design flaw that will be guaranteed to wipe out the product on the basis of natural selection.You can obviously add the equally flawed ■■■■■■■ V8’s to that list.As for the L10 like any other downsizing attempt the question was/is why bother compared to the reliability and output benefits of the proven larger capacity 14 litre.

Well that is arguing against yourself. The L10 was conceived because ■■■■■■■ wanted a share of the market for lighter, smaller engines in a specific power range. They did this because they could see what the customer wanted and they didn’t at the time have a suitable product. They could have ignored what the market at the time was demanding, but then they would not have enjoyed the success which was to come to them.

From the IRTE article, having mentioned the external dimensions of the Cursor 16 it goes on to say:

“Further, ensuring sufficient cooling for a 600bhp-plus Cursor 16 beneath a Stralis cab would require additional engineering time (and money) from the Italian truck maker that might be more profitably spent elsewhere. And then there’s the not insignificant matter of creating a drivetrain to match it. - See more at: transportengineer.org.uk/tra … If2gE.dpuf”

As indicated before, the AEC Monobloc engine being designed before 1954 with particular reference to the wishes of not only the company’s largest customer, but also a significant shareholder in the business. This customer was emphasising space and weight considerations as being of great importance. Even so when the prototype vehicle was constructed using the preceding A204 engine it had to have the cooling radiator and fan fitted horizontally under the floor of the vehicle because there was not room to accommodate them in the normal position without contravening Construction and Use overall length regulations.

Just about everything to do with a vehicle is some sort of compromise between conflicting dis/benefits. The AEC had settled upon its chosen particular stroke length for some reason. It had tried a 146mm stroke in its very successful, but certainly not smooth running 7.7 engine.

Whatever the rights or wrongs of the engine’s internal dimensions might be, there can have been little to gain from constructing a product which in engineering terms would be required 30 years hence, if the company should go out of business in the meantime because its customers had gone elsewhere.

Spot on and the l10 and later m11 went on to keep the British builders going for a few years.
A ERF with a l 10 or m11 ■■■■■■■ Eaton twin split and rock well axle was a good no frills decent to drive fleet truck with good reliability good fuel returns and cheap to run in its day.

[carryfast]

ramone:
The AV760 /TL12 came from the continuous development of the 11.3 which became the AV/AH690 - AV/AH691 then the AV760 in 12.47 litre form then turbocharged to bring in the TL12 so its roots go back to at least the early 50s so look again at good engine and flawed design because a basic design that develops and stays in production for at least 30 years doesnt seem flawed to me but no doubt you know different

You need to look at it from a different angle.The 760,not the 690,development was aimed at what every one in the day knew was coming.Just like the Rolls Eagle was.Read the CM article from 1966 which I posted.IE the Eagle was developed for present ‘and’ ‘future’ needs for high speed distance trunking at heavier weights.So it’s obviously an early 1960’s design made to meet the foreseeable ‘future’ needs described above it was never meant to be designed for the environment of the 1950’s or for that matter just the 1960’s.The definition of ‘future’ in this case hopefully meaning a bit ( lot ) more than just an effectively 10,or at best well under 20,year production life unless Leyland had loads of money for continuous frequent clean sheet design upgrades ( no chance of that ).

With all that in mind the definition of high speed above means high road speeds and heavier weights speaks for itself and for all that we’ll need to maximise the potential for specific torque output.In which case it wasn’t rocket science for AEC’s designers to realise that using the old 690’s stroke measurement wasn’t going to cut it over the design production life of the engine.

Unlike the luxury of the type of stroke measurement enjoyed by ■■■■■■■■ and the Eagle’s designers having already been set previously by people who obviously knew how to design truck engines.Especially when their tolerance of ever higher levels of boost was combined with that.

[carryfast]

kr79:
Spot on and the l10 and later m11 went on to keep the British builders going for a few years.
A ERF with a l 10 or m11 ■■■■■■■ Eaton twin split and rock well axle was a good no frills decent to drive fleet truck with good reliability good fuel returns and cheap to run in its day.

I’m guessing there aren’t many max weight rigids running about with sub 12 litre motors these days ?.

[gazsa401]

ramone:

windrush:

ramone:
I cant really remember the RR Eagle being an outstanding performer so why is it so relevant■■?? when was the 290L introduced i remember the 265li and a local haulier buying some Fodens with the 290L in and an advertising campaign but they were very average this must have been around 79 - `80 the same haulier moved to Cat very quickly

We ran a fleet of Foden’s with 265 and 265Li Roller’s and they were brilliant performers but heavier on fuel that the previous Gardner 201’s. Mine did 10 years without even an injector change, but usually they were rebuilt after 6 or 7 years. We did have one with a Cat engine in it, that soon got ripped out and replaced with a ■■■■■■■ following continual head gasket failures, and one with a L10 and that was a resounding disaster at first but a fresh engine sorted it finally.

Pete.

I heard they were plague by oil leaks but could hold their own on the road H.Baker at Bradford ran some and they were impressed with the mpg but then again they were 290Ls on motorway work which is a totally different ball game to your work i would expect . I had a 320 Gardner and loved it , again they were supposed to be bad for oil leaks and mine was never a problem , H.Bakers had some and they eventually retuned them to 350 bhp because they were sluggish mine was anything but

We ran some early 301s with the L10s fitted they were good on fuel but leaked terrible both oil and water especially the side plate gaskets
We never bought any more ■■■■■■■ until a few years later 2 Roadtrains with the 290 fitted
Our fleet engineer wouldn’t have them
They only came because of a good deal the firm got

[kr79]

Daf and volvo and possibly renault do an 11 litre engine up to around 400 bhp in there 8 wheeler chasis which is popular with the more weight concious aggregate hauliers.
MANs d20 is a 10 litre odd engine up to about 440bhp.
Iveco offer big power from relatively small engines in the cursor range.
The fact is with 420 to 480 been seen as the norm for a fleet tractor at 44 ton now despite advances in technology 12 -13 litre engines are about right to produce this sort of power with an acceptable combination of fuel efficency and not been to stressed that it offers an acceptable life span.

[windrush]

gazsa401:
We ran some early 301s with the L10s fitted they were good on fuel but leaked terrible both oil and water especially the side plate gaskets
We never bought any more ■■■■■■■ until a few years later 2 Roadtrains with the 290 fitted
Our fleet engineer wouldn’t have them
They only came because of a good deal the firm got

I drove two six wheeler’s with L10’s and they were both bad for oil and water leaks plus very little bottom end power, not an engine that I rated highly. However they seemed a popular choice.

Pete.

[tubbysboy]

Slightly off topic, I bought a c reg seddon Atkinson with a l10 290 ■■■■■■■ in it. In fairness it was the only good thing about the lorry, rest of it was horrible, but the engine never gave any problems at all.
However I knew someone who had a l10 350 in a foden artic that never worked correctly. If I remember correctly it was one of the first with the celect brain connected to it. It would ■■■■ burp and ■■■■ ball about but never with any rhyme or reason. ■■■■■■■ blamed lack of oil change even the lorry was bought new and didn’t do a lot of work until it started messing about.

He then bought the last alpha series fitted with 380 celect l10 and as far as I know they gave very good service, and would pull a house down, and good on fuel.

[ramone]

Carryfast:

ramone:
The AV760 /TL12 came from the continuous development of the 11.3 which became the AV/AH690 - AV/AH691 then the AV760 in 12.47 litre form then turbocharged to bring in the TL12 so its roots go back to at least the early 50s so look again at good engine and flawed design because a basic design that develops and stays in production for at least 30 years doesnt seem flawed to me but no doubt you know different

You need to look at it from a different angle.The 760,not the 690,development was aimed at what every one in the day knew was coming.Just like the Rolls Eagle was.Read the CM article from 1966 which I posted.IE the Eagle was developed for present ‘and’ ‘future’ needs for high speed distance trunking at heavier weights.So it’s obviously an early 1960’s design made to meet the foreseeable ‘future’ needs described above it was never meant to be designed for the environment of the 1950’s or for that matter just the 1960’s.The definition of ‘future’ in this case hopefully meaning a bit ( lot ) more than just an effectively 10,or at best well under 20,year production life unless Leyland had loads of money for continuous frequent clean sheet design upgrades ( no chance of that ).

With all that in mind the definition of high speed above means high road speeds and heavier weights speaks for itself and for all that we’ll need to maximise the potential for specific torque output.In which case it wasn’t rocket science for AEC’s designers to realise that using the old 690’s stroke measurement wasn’t going to cut it over the design production life of the engine.

Unlike the luxury of the type of stroke measurement enjoyed by ■■■■■■■■ and the Eagle’s designers having already been set previously by people who obviously knew how to design truck engines.Especially when their tolerance of ever higher levels of boost was combined with that.

Im not sure what you dont understand here , the TL12 /AV760s roots are from the 11.3 which was designed late 40s early 50s and was developed and rebored out to 12.47 litres note late 40s early 50s no motorways they didnt design them to run flat out all day long the 690s 691s were a development of the 11.3s so a design from late 40s early 50s still being produced in the early 80s in my book isn`t a flawed design and again i will ask you what problems in service did the 12.47 litre engines cause. The ■■■■■■■ and RR were much more modern designs from another era when our motorway network was just beginning to grow

[carryfast]

ramone:

Carryfast:
You need to look at it from a different angle.The 760,not the 690,development was aimed at what every one in the day knew was coming.Just like the Rolls Eagle was.Read the CM article from 1966 which I posted.IE the Eagle was developed for present ‘and’ ‘future’ needs for high speed distance trunking at heavier weights.So it’s obviously an early 1960’s design made to meet the foreseeable ‘future’ needs described above it was never meant to be designed for the environment of the 1950’s or for that matter just the 1960’s.The definition of ‘future’ in this case hopefully meaning a bit ( lot ) more than just an effectively 10,or at best well under 20,year production life unless Leyland had loads of money for continuous frequent clean sheet design upgrades ( no chance of that ).

With all that in mind the definition of high speed above means high road speeds and heavier weights speaks for itself and for all that we’ll need to maximise the potential for specific torque output.In which case it wasn’t rocket science for AEC’s designers to realise that using the old 690’s stroke measurement wasn’t going to cut it over the design production life of the engine.

Unlike the luxury of the type of stroke measurement enjoyed by ■■■■■■■■ and the Eagle’s designers having already been set previously by people who obviously knew how to design truck engines.Especially when their tolerance of ever higher levels of boost was combined with that.

Im not sure what you dont understand here , the TL12 /AV760s roots are from the 11.3 which was designed late 40s early 50s and was developed and rebored out to 12.47 litres note late 40s early 50s no motorways they didnt design them to run flat out all day long the 690s 691s were a development of the 11.3s so a design from late 40s early 50s still being produced in the early 80s in my book isn`t a flawed design and again i will ask you what problems in service did the 12.47 litre engines cause. The ■■■■■■■ and RR were much more modern designs from another era when our motorway network was just beginning to grow

In terms of bore and stroke measurements the ■■■■■■■ and Rolls weren’t more modern designs than the 690 more like pre dated it.It’s just that unlike AEC’s designs those measurements were more suited to providing a decent torque output which is my point.On that note the 142 mm stroke of the 590-690 series was actually introduced in 1958 in which case it would take the even worse 130 mm stroke of the 410 and 470 to meet your late 1940’s early 1950’s timeline.

While the fact that AEC chose what was effectively just a bored out variation on the previous 690 theme,in a design for introduction into the environment applying from the mid 1960’s,actually proves my point.Unless that is as I said they thought that Leyland Group was awash with enough cash to replace the thing with a clean sheet design for introduction in the late 1970’s.So yes you’re right AEC used a 1950’s design,that even by 1950’s standards had a too short stroke measurement,that not surprisingly then helped to wipe out Leyland Group having predictably found itself out of its depth way before,what should have been,the end of its design production life.

All because AEC’s engineers were obviously going by the same logic as yours when they designed the 760.Based as it was on the built in obsolesence of the 690,which itself contained the same design flaw of a 142 mm stroke,instead of the 6 inch one of its Rolls and ■■■■■■■ contemporaries.You couldn’t make this zb up.

[lawrence_dunbar]

[carryfast]

kr79:
Daf and volvo and possibly renault do an 11 litre engine up to around 400 bhp in there 8 wheeler chasis which is popular with the more weight concious aggregate hauliers.quote]

The point in that case being not to compromise on stroke measurement to get the reduced capacity.IE 123 x 152 in the case of the Volvo for example.

[saviem]

Evening all,

Well whil`st we all disappear up our own exhaust pipe analysing to the “ninth degree” the flaws in the basic engineering…(.no more than in any, and I mean any, other manufacturers range), the arguments so far expounded ignore, …(except for the learned writings of NMM, gingerfold, cav551,ramone, and kr79)…and that is not to ignore the learned representations of others, but those most excellent posts have concentrated upon analysis of the rail sidings generated by dear old carryfast…not they are not valid in some areas… but they are sidings, not the core reasons!

I will be brief,

Political interference that ignored commercial objectives, but chose to concentrate upon political outcomes…primarily preservation of jobs in a worthless business…BMCs car division.

As gingerfold quite rightly pointed out, “2 men for 1 job”…so one goes…and the fall out from Leyland/AEC/Guy /Scammell/ and oddly BMC…gave the new importers men with ability, and an axe to grind to catapault "their " product into the market place…and boy, did they just do that, …because they knew the weak spots of their former employer…Service to the end user…however small his operation was…“get his cash”…and they did!

I was hoping that Tomdhu would give us more insight into what happened in exports world wide…I well remember just how good was the Austin WF serie…replaced in the `80s by the Bathgate built Landmaster…with its weak bodywork, and flimsy electronics…why did that happen? The WF was regarded in India, Pakistan, Afghanistan, as strong as the Bedford TJ…what did Leylands “engineers” do to dumb it down!!!

Why did Leyland choose to link with Hotchkiss in France, when AEC had already established themselves , along side with BMC with Willeme…400 Dealers…The deal, Hotchkiss marketed in the UK…did you see any of their funny .6354 Perkins 7 tonnners…I did not…and Leyland sold in France by Hotchkiss…well there were a few…Bears…(?), 4x2 tractors with the fibregass LAD sleeper cab as developed for Israel…and made to tilt by Guy prior to the Big J…

South America…AEC so strong, yet it was killed, and in the case of Argentina, Leyland management lost everything overnight by killing the AEC subsidiary, and failing to open their own before the “local content” rules were introduced…And AEC were leading the market!

My colleagues in the Bus and Coach division of RVI spoke in awe of what the potential for AEC/ Leyland was in Europe, (before the tariff barriers came down), yet Leyland management simply did not realise just how strong their image was, or simply ignored it…but why■■?

Leyland Nigeria…perhaps best forgotten, my old friend Bernard Momin, number one in the RVI Nigerian outfit, (who later ran the Renault Trucks operation in the UK), told me that no one believed just how Leyland management “shot themselves” in Nigeria… and that was where the Landmaster was to be built for the African market!..

I can only speak of the French operation, that did quite well with the Marathon, and Terrier, and Sherpa, but when Roger Doughty came, and the T45 was the product, with the Rolls, and a 13 tonne SOMA axle, boy they got sales…(but sales on the back of the Rolls Royce funded Saviem SM with the Rolls @320 hp, and a 9 speed Fuller, …our fleet clients loved that combination…then came our forced marriage to Berliet and that “premium” specification was no more…until Leyland launched “Le Camion Rolls Royce”, and that was how the T45 was known…and she sold well, (too B well)!!! Below "our prices for the TR305, and mid way to the TR356…and Leyland were not “dumping”, …(nor were ERF with their last go at Europe…it was just that ERF could not get their dealership right)…and for goodness sake those plonkers at Sandbach really did not realise what they had in MABO!..but that is another story!..

There is a lot more to the failure of Leyland than their engineering…and that was not as bad as many would suppose…(perhaps if more had worked within the subtrafuge, and political manouvering within any large vehicle producing operation, then the simplistic reasoning that it was all down to the engineering would be relegated to the small box that is its true relevance)!!!..now that should excite some posters!!!

Politics, internal, and of more significance external, that is the core reason for Leylands failure…coupled with a managerial chain of such complexity, and gross egotistical nature, that the end user, (unless of several hundreds of units), became a person of no significance, and his problems of little relevance!

Cheerio for now.

[carryfast]

Saviem:
I can only speak of the French operation, that did quite well with the Marathon, and Terrier, and Sherpa, but when Roger Doughty came, and the T45 was the product, with the Rolls, and a 13 tonne SOMA axle, boy they got sales…(but sales on the back of the Rolls Royce funded Saviem SM with the Rolls @320 hp, and a 9 speed Fuller, …our fleet clients loved that combination…then came our forced marriage to Berliet and that “premium” specification was no more…until Leyland launched “Le Camion Rolls Royce”, and that was how the T45 was known…and she sold well, (too B well)!!!

Which seems to support the idea that the T45 only reached its true potential on the basis of it being a non in house ( assembled ) product built within what was ‘supposed’ to be an in house production operation.The reason for that being the engineering limitations within Leyland’s own engine supply operation in the form of the TL12.Those ‘limitations’ being built into it from its outset.In a similar way as BMC’s Issigonis designed fwd heaps had inevitably consigned the car side to its financial doom even without the help of an arguable over manned militant workforce.

[kr79]

Saviem:
Evening all,

Well whil`st we all disappear up our own exhaust pipe analysing to the “ninth degree” the flaws in the basic engineering…(.no more than in any, and I mean any, other manufacturers range), the arguments so far expounded ignore, …(except for the learned writings of NMM, gingerfold, cav551,ramone, and kr79)…and that is not to ignore the learned representations of others, but those most excellent posts have concentrated upon analysis of the rail sidings generated by dear old carryfast…not they are not valid in some areas… but they are sidings, not the core reasons!

I will be brief,

Political interference that ignored commercial objectives, but chose to concentrate upon political outcomes…primarily preservation of jobs in a worthless business…BMCs car division.

As gingerfold quite rightly pointed out, “2 men for 1 job”…so one goes…and the fall out from Leyland/AEC/Guy /Scammell/ and oddly BMC…gave the new importers men with ability, and an axe to grind to catapault "their " product into the market place…and boy, did they just do that, …because they knew the weak spots of their former employer…Service to the end user…however small his operation was…“get his cash”…and they did!

I was hoping that Tomdhu would give us more insight into what happened in exports world wide…I well remember just how good was the Austin WF serie…replaced in the `80s by the Bathgate built Landmaster…with its weak bodywork, and flimsy electronics…why did that happen? The WF was regarded in India, Pakistan, Afghanistan, as strong as the Bedford TJ…what did Leylands “engineers” do to dum

b it down!!!

Why did Leyland choose to link with Hotchkiss in France, when AEC had already established themselves , along side with BMC with Willeme…400 Dealers…The deal, Hotchkiss marketed in the UK…did you see any of their funny .6354 Perkins 7 tonnners…I did not…and Leyland sold in France by Hotchkiss…well there were a few…Bears…(?), 4x2 tractors with the fibregass LAD sleeper cab as developed for Israel…and made to tilt by Guy prior to the Big J…

South America…AEC so strong, yet it was killed, and in the case of Argentina, Leyland management lost everything overnight by killing the AEC subsidiary, and failing to open their own before the “local content” rules were introduced…And AEC were leading the market!

My colleagues in the Bus and Coach division of RVI spoke in awe of what the potential for AEC/ Leyland was in Europe, (before the tariff barriers came down), yet Leyland management simply did not realise just how strong their image was, or simply ignored it…but why■■?

Leyland Nigeria…perhaps best forgotten, my old friend Bernard Momin, number one in the RVI Nigerian outfit, (who later ran the Renault Trucks operation in the UK), told me that no one believed just how Leyland management “shot themselves” in Nigeria… and that was where the Landmaster was to be built for the African market!..

I can only speak of the French operation, that did quite well with the Marathon, and Terrier, and Sherpa, but when Roger Doughty came, and the T45 was the product, with the Rolls, and a 13 tonne SOMA axle, boy they got sales…(but sales on the back of the Rolls Royce funded Saviem SM with the Rolls @320 hp, and a 9 speed Fuller, …our fleet clients loved that combination…then came our forced marriage to Berliet and that “premium” specification was no more…until Leyland launched “Le Camion Rolls Royce”, and that was how the T45 was known…and she sold well, (too B well)!!! Below "our prices for the TR305, and mid way to the TR356…and Leyland were not “dumping”, …(nor were ERF with their last go at Europe…it was just that ERF could not get their dealership right)…and for goodness sake those plonkers at Sandbach really did not realise what they had in MABO!..but that is another story!..

There is a lot more to the failure of Leyland than their engineering…and that was not as bad as many would suppose…(perhaps if more had worked within the subtrafuge, and political manouvering within any large vehicle producing operation, then the simplistic reasoning that it was all down to the engineering would be relegated to the small box that is its true relevance)!!!..now that should excite some posters!!!

Politics, internal, and of more significance external, that is the core reason for Leylands failure…coupled with a managerial chain of such complexity, and gross egotistical nature, that the end user, (unless of several hundreds of units), became a person of no significance, and his problems of little relevance!

Cheerio for now.

Another excellent post from one of the most informed and intresting posters on this forum.

[gingerfold]

As usual Saviem makes several very valid points. As for politics and government input into BL we haven’t even touched on that yet and Bob Fryars had some interestiing comments in the last article of his I read and I will look at in due course.

Let me try and bring into context AEC’s engine development from the early 1930s and its first successful diesel engine design. Like Leyland AEC wanted a reliable CI oil engine and after prototypes settled on an 8.8 litre design with 142 mm stroke length in about 1933. Initially it was an indirect injection type with cylinder heads designed by Harry Ricardo. Lawrence Pomeroy, another famous name from that era was also an AEC engineer. Thereafter AEC enlisted Ricardo into much of its future engine development. (Ricardo and Pomeroy, hardly mugs in engineering terms and today Ricardo Engineering is a world leading engineering consultancy). The smaller 7.7 litre followed, again with either indirect or direct injection and this remained in production from 1937 to 1956. The 8.8 litre formed the basis of the 9.6 litre when development commenced in 1939 (142 mm stroke). The 9.6 set AEC’s reputation for engine reliabilty and ease of starting. The 9.6 fired up on the first compresion stroke whereas most competing diesels required minutes of cranking from cold, Ki-Gas and burning rags over the air intakes. The separate crankcase / block 9.6 was bored out to the 11.3 litre in 1952. In 1958 the monobloc wet liner A590/A690 was introduced retaining the respective bore/stroke dimensions of the 9.6/11.3 litre(s). These then developed into the dry liner A691/A760 in 1964, a dvelopment done at the instigation of Stanley Markland in less than two years. The A760 remained in production until 1979. Developmnent of the TL12 started in 1971 and it was ready in 1973. So the 142 mm stroke actually went back to the 8.8 litre of circa 1934 and it can be argued it was well out of date, but for 30 years it had served AEC very well, and in the early 1960s no one envisaged or foresaw what the operational demands and power requirements of a truck engine would be in the 1980s. Back then we were only just entering the Motorway age. In a company like AEC or Leyland all engine design was a compromise to cover various applications, automotive, stationery, marine etc all with their own operating cycles.

[newmercman]

I can’t believe we are still banging on about bore and stroke, as soon as I see it mentioned I, like a lot if you, move on to the next post.

I did pick up a bit about 12litre engines before skipping to something that wasn’t encouraging me to gouge out my eyes with a rusty spoon and I would like to add my views to that subject.

In the late 70s and onwards, including post 1983 and the introduction of 38tonnes GVW right up until the early 2000s there were a vast quantity of sub 12litre lorries out on the roads. The Daf 2300/2500 range, the Volvo F86/F7 and F88/F10, the Scania 81/82 and later the 92/93, the Renault 260/290, anything fitted with a ■■■■■■■ L10/M11, the 340hp IVECOs, Mercedes Benz V6 models 1733/1834 and MAN with its 5pot 272/292. Now all of these manufacturers also had 12+litre engines in their ranges and yet they all spent vast sums of money developing and producing smaller engines as well, by definition this means that they were all wrong, despite the success of all those different lorries and despite all the companies that ran them and got good service from them, the designers had somehow managed to pull the wool over everyone’s eyes and flog them all a boat anchor…

[gazsa401]

newmercman:
I can’t believe we are still banging on about bore and stroke, as soon as I see it mentioned I, like a lot if you, move on to the next post.

I did pick up a bit about 12litre engines before skipping to something that wasn’t encouraging me to gouge out my eyes with a rusty spoon and I would like to add my views to that subject.

In the late 70s and onwards, including post 1983 and the introduction of 38tonnes GVW right up until the early 2000s there were a vast quantity of sub 12litre lorries out on the roads. The Daf 2300/2500 range, the Volvo F86/F7 and F88/F10, the Scania 81/82 and later the 92/93, the Renault 260/290, anything fitted with a ■■■■■■■ L10/M11, the 340hp IVECOs, Mercedes Benz V6 models 1733/1834 and MAN with its 5pot 272/292. Now all of these manufacturers also had 12+litre engines in their ranges and yet they all spent vast sums of money developing and producing smaller engines as well, by definition this means that they were all wrong, despite the success of all those different lorries and despite all the companies that ran them and got good service from them, the designers had somehow managed to pull the wool over everyone’s eyes and flog them all a boat anchor…

Totally agree but the odd one out on this topic will argue all day long until we all fall in to line and accept he’s right and we’re are not
Flogging a dead horse comes to mind
No matter how many times things are explained by those who have owned operated ran and used products throughout their time it still isn’t right
I’ve tried to explain why the firm I worked for used a certain engine right up until we couldn’t buy them anymore
But alas it’s always wrong every single topic is hijacked where a good discussion is being debated
I do try and stay clear but I love to read some of the more knowledgeable posters comments and their experiences on here

[carryfast]

gingerfold:
As usual Saviem makes several very valid points. As for politics and government input into BL we haven’t even touched on that yet and Bob Fryars had some interestiing comments in the last article of his I read and I will look at in due course.

Let me try and bring into context AEC’s engine development from the early 1930s and its first successful diesel engine design. Like Leyland AEC wanted a reliable CI oil engine and after prototypes settled on an 8.8 litre design with 142 mm stroke length in about 1933. Initially it was an indirect injection type with cylinder heads designed by Harry Ricardo. Lawrence Pomeroy, another famous name from that era was also an AEC engineer. Thereafter AEC enlisted Ricardo into much of its future engine development. (Ricardo and Pomeroy, hardly mugs in engineering terms and today Ricardo Engineering is a world leading engineering consultancy). The smaller 7.7 litre followed, again with either indirect or direct injection and this remained in production from 1937 to 1956. The 8.8 litre formed the basis of the 9.6 litre when development commenced in 1939 (142 mm stroke). The 9.6 set AEC’s reputation for engine reliabilty and ease of starting. The 9.6 fired up on the first compresion stroke whereas most competing diesels required minutes of cranking from cold, Ki-Gas and burning rags over the air intakes. The separate crankcase / block 9.6 was bored out to the 11.3 litre in 1952. In 1958 the monobloc wet liner A590/A690 was introduced retaining the respective bore/stroke dimensions of the 9.6/11.3 litre(s). These then developed into the dry liner A691/A760 in 1964, a dvelopment done at the instigation of Stanley Markland in less than two years. The A760 remained in production until 1979. Developmnent of the TL12 started in 1971 and it was ready in 1973. So the 142 mm stroke actually went back to the 8.8 litre of circa 1934 and it can be argued it was well out of date, but for 30 years it had served AEC very well, and in the early 1960s no one envisaged or foresaw what the operational demands and power requirements of a truck engine would be in the 1980s. Back then we were only just entering the Motorway age. In a company like AEC or Leyland all engine design was a compromise to cover various applications, automotive, stationery, marine etc all with their own operating cycles.

Apologies to nmm but this type of stuff is the foundations which have to be got right in order for a truck engine to survive as a marketable product. By that example it seems obvious that someone there got their wires crossed concerning the understanding of bore stroke ‘ratios’ as opposed to stroke measurements.IE a 142 mm stroke 8.8 litre motor is a totally different thing to a 142 mm stroke 12.4 litre one.The former will work while the latter won’t.

[carryfast]

newmercman:
I can’t believe we are still banging on about bore and stroke, as soon as I see it mentioned I, like a lot if you, move on to the next post.

I did pick up a bit about 12litre engines before skipping to something that wasn’t encouraging me to gouge out my eyes with a rusty spoon and I would like to add my views to that subject.

In the late 70s and onwards, including post 1983 and the introduction of 38tonnes GVW right up until the early 2000s there were a vast quantity of sub 12litre lorries out on the roads. The Daf 2300/2500 range, the Volvo F86/F7 and F88/F10, the Scania 81/82 and later the 92/93, the Renault 260/290, anything fitted with a ■■■■■■■ L10/M11, the 340hp IVECOs, Mercedes Benz V6 models 1733/1834 and MAN with its 5pot 272/292. Now all of these manufacturers also had 12+litre engines in their ranges and yet they all spent vast sums of money developing and producing smaller engines as well, by definition this means that they were all wrong, despite the success of all those different lorries and despite all the companies that ran them and got good service from them, the designers had somehow managed to pull the wool over everyone’s eyes and flog them all a boat anchor…

As I’ve said above getting the basics right is the difference between a lemon and something which will at least provide a decent design production life.While the overall capacity issue is a totally different argument.But if you’re saying that the DAF 2300/2500,let alone the F7 ,was the way to go in heavy trucks then how many manufacturers are offering that that type of spec to pull 30 t + around now and if not why not.

On that note kr made the example of the Volvo D11.Which,at 123 x 152 is the last example you need,if you want to make the case that smallest is best,or the actual subject of my comments the 760/TL12 wasn’t a lemon from the time it was on the drawing board.