Carryfast:
…
Yet you still say that Stokes was the main player in the destruction of AEC and with it Leyland Truck and Bus division.Not Edwardes.Strange.
Have you read Edwardes’ autobiography?
[zb]
anorak:Carryfast:
newmercman:
[zb]
anorak:
Back to the bore/stroke dogma, without even doing the calculation to verify it (which, I believe, is what started this thread off in the first place).Remember who started the thread, no way will he complain about off topic antics.
It started with a comparison of L12/TL12 v Rolls Eagle and that’s where it’s mostly stayed with other relevant stuff.
Calculation what calculation.
I’ve said piston speed isn’t an issue at truck engine speeds at well over 152 mm stroke let alone just that much.Engine speeds can obviously reduce to get the equivalent power output as leverage increases.
Haven’t got a clue what Anorak was referring to regarding 2 x BMEP or why he was referring to such a figure.
I thought he was referring to tensile loads on the piston and rod assembly which logically means peak power/max governed rpm between the exhaust and inlet strokes.Don’t ask me what it is in either case.If Anorak knows it then tell us.
Unless he’s going to tell us that the combined 14 main bearing fastenings aren’t going to amount to the need to contain a lot more tensile force applied by the pistons acting on them at peak torque rpm than the big end fastenings stopping the pistons and rods flying away from the crankshaft at peak power at 2,100 and 2,200 rpm respectively.
The same applies to the head fastenings stopping the head being blown off by the opposite force acting on it during the power stroke.Here’s a clue that’s more than 2 x BMEP.
Do the calculation. Use whatever peak pressure you like, but provide a source for your information. I only said 2x BMEP to give you a number to work with. It would have been easy enough to substitute another number into your equation. If you had done the calculation, it would have shown that you know what you are talking about. So far, all you have done is avoid the issue, while ramping up the b.s.
You’re the one who jumped from the connection between piston speed and resulting tensile loads, then for some reason wanted me to work with ‘your’ 2 x BMEP figure as a comparison to suggest that compressive loads equal those of the tensile loads on the piston and rod assembly.
As I said the relative difference, between the combined tensile strength of main bearing cap and block to head fastenings, v those of the big end cap fastenings shows who’s talking bs and it ain’t me.
So remind me what load situation is the piston and rod assembly under, with the main bearing cap and head fastenings under the most tension and the relationship between those loadings.
As opposed to the big end bearing cap fastenings at governed engine rpm.
Good luck with using the big end cap fastenings to hold the head down and the main bearings together at peak torque of 100 lb/ft per litre.
Although I’m surprised that AEC didn’t try it on a TL12 boosted to that level because it seemed like a good idea at the time and the compressive loads acting on the piston and rod assembly can’t possibly be greater than the tensile loads acting on it. 
[zb]
anorak:Carryfast:
…
Yet you still say that Stokes was the main player in the destruction of AEC and with it Leyland Truck and Bus division.Not Edwardes.Strange.Have you read Edwardes’ autobiography?
No I wouldn’t want to read his lies.
But I’m guessing it will say that putting the TL12 in the Roadtrain at launch instead of bringing Rolls into the Leyland Group to power it before then and that the Rover SD1 and Triumph Acclaim and Rover 820 were all worthy contenders to BMW 3 and 5 series and splitting the truck and bus divisions and closing down AEC was all a good thing for Leyland.
newmercman:
I read a book on BL a while back, can’t remember the title, it’s on a dead Kindle so can’t retrieve it, anyway it gave the whole BL story and Stokes was THE man.
Why and how Stokes not Edwardes assuming we want to run with the Rolls v TL12 T45 story to the obvious advantage of DAF.
Stokes put the TL12 in the Marathon which everyone ( except me ) is saying was a good thing.
Edwardes put it in the T45/Roadtrain which you’ve agreed was a stupid thing.
Edwardes also closed down AEC not Stokes.Which Gingerfold is obviously ■■■■■■ off about but he’s blaming Stokes anyway even though Stokes didn’t do it.All Stokes did was to agree with Gingerfold and Ramone that the TL12 would do the job and put his money where his mouth was and gave AEC the job.
At least until Stokes had retired.
Carryfast:
gingerfold:
Carryfast:
Which matters how to the fact that the TL12 needed to be knocked on the head at the design stage of T45 and Rolls Royce brought on board instead to power it.That decision would have been way above Stokes’ pay grade.That would have been the decision of Michael Edwardes who was at that time the boss of the NEB which of course ultimately controlled and funded both state rescued firms. ( That name again ), the man who was then parachuted into run Leyland Group and who had stitched up Rover and Triumph to the benefit of BMW done it again in the case of Leyland Trucks followed by Buses to the benefit of DAF and Volvo.
As for Stokes he was effectively powerless with just a token horary role by 1975 and left Leyland in 1977 well before the T45 hit the roads.
Edwardes and his government handlers were the problem here not Stokes.I will try and explain how corporate life works at a senior level, although I realise that I’m probably wasting my time and you will ignore it.
Donald Stokes as Sales Director of Standard Triumph was appointed to the Board of an acquired company. It was a position that allowed him to oversee sales operations at Standard. As a truck and bus salesman he had little or no understanding of the car sales market but he would advise the Standard sales team on certain matters such as discounts. Stanley Markland was reporting directly to Spurrier and the Leyland Board as he attempted to stem losses at Standard. Spurrier was the boss of both Markland and Stokes. Stokes still retained his Leyland sales directors’ duties. That is what happens when one company acquires another, initially the purchasing company puts its own management into the acquired company to assess what is going on and recommend changes to bring the acquisition into line with the management practises and style of the purchaser. Markland’s expertise was in production and financial control; Stokes was a successful salesman. Markland was not Stokes’ boss at Standard or anywhere else in the Leyland group of companies.The comment I have highlighted is complete balderdash. Stokes was the main man.
Markland was the MD of Standard Triumph as of 1961.Stokes was sales director obviously UNDER Markland.Markland resigned at the end of 1963.Stokes then became Chairman of… Standard Triumph.
What was William Black’s role in all this.Remind me where he came from.Obviously way out ranking Stokes at that point after Spurrier’s demise.
What actual evidence have you got that Stokes had any input whatsoever at the design and signing off stages of the 691 and 760 ?.Which was obviously well before 1965.
Remind me what position and power that Stokes had at the design stages of the T45/Roadtrain ?.
Let’s say 1975 - 78 ?.Even if he was still MD of Leyland Group at that time, which he wasn’t, how would he have had the power to say bring Rolls Royce in house.Which would have been a deal under the control of the NEB and only the NEB itself answerable to the Government.
You say the TL12 was a great motor, which it wasn’t.
In which case how does that fit any supposed conspiracy of Stokes to destroy AEC.The TL 12 was a product of AEC’s design team ( usual MO lets just go with the 760’s big bore and Routemaster bus motor’s stroke it’ll be fine ).Not a Leyland design and it was Stokes who’d obviously over seen it.Remind me who was running Leyland Group and for how long when AEC engine production was actually transferred to Leyland.Followed by when AEC was actually closed down.In view of your claims that Stokes wanted to wipe out AEC ?.
Asking AEC to design and provide Leyland’s only real heavy truck engine option, which you say was a great motor, was a strange way of doing it.
Yet you still say that Stokes was the main player in the destruction of AEC and with it Leyland Truck and Bus division.Not Edwardes.Strange.
I’m really getting fed-up with all this going round in circles. I’ll have one last attempt to try and spell out big business management structures.
Firstly the difference between Executive Chairman and non-Executive Chairman. Spurrier was the former with responsibility for day-to-day running of the business, Black was the latter, he chaired the monthly Board meeting. The Board comprised Executive Directors (Markland and Stokes for example), and non-Executive Directors, ‘captains of industry’ from other businesses that got well paid for attending a monthly Board meeting and advising the Executive Directors. As Managing Director of the entire British Leyland Group Stokes had complete autonomy in the day-to-day running of the entire business. To disagree with that is plainly wrong.
Fast forward to the Edwardes era and a few years before. The role of the NEB and its majority shareholding in British Leyland from the mid-1970s hasn’t been touched on, but undoubtedly, as BL was effectively nationalised Stokes’ role would not have been as dictatorial as previously. He had political issues to deal with. The run-down of AEC and Southall commenced in 1977 with the cessation of all the AEC truck models, except for the Marathon and some outstanding MoD orders that had to be fulfilled. Marathon production eventually transferred to Scammell. The closure of Southall WAS Stokes’ decision. No argument or doubt about it.
Michael Edwardes was appointed with the brief to sort out the car making decisions once and for all. That is where his main focus of attention was. He inherited the T45 project, started in 1974, and waved it through to completion. He approved the building of a new assembly factory at Leyland for the T45, which is where DAFs are assembled to this day. I have been on two factory tours in the last few years and they were very good and interesting.
The continual “rubbishing” of AEC engines and products. AEC was the second largest, (after Leyland), commercial vehicle manufacturer in the UK. Like ALL vehicle builders that develops its own engines it had some failures over the years, but the vast majority of its output of 67 years was successful and well-liked by operators and drivers alike. Hundreds of operators at home and abroad, thousands of drivers. Were all these people wrong? I don’t think so.
As for the technical aspects of engine design. The vast majority of operators and purchasers through the decades have no interest in how, or why, an engine is designed (personally I do have some interest), but all the operator is concerned about is the reliability, the economy, the servicing and repair costs, the mileage run between overhauls, minimum downtime of the vehicle, whole-life running costs, and suitability for the work it has to do. If the engine has limited, or none, development potential for fitting in new models ten years hence is of no consequence to the operator. That is the province of the engine manufacturer and its design and development team. Another major consideration was, and is today, after-sales service and support.The mainstream AEC engines of the 1960s and 1970s, including the TL12, fulfilled all the required criteria of operators that bought them. The Leyland Group It had far more regional main depots and independent dealerships than any other UK manufacturer. The AEC after sales support was reckoned to be the best in the business and became the model for DAF, with several former AEC managers moving to DAF. Can you honestly say what the Diesel engine of 2030 will be? If there will be any new, radical, designs? Or will every new truck have an electric motor?
In the early and mid-1970s the UK maximum GVW was 32 tons; a 220 bhp engine was deemed perfectly adequate. Very few operators on standard UK general haulage and own-account work had any interest in more powerful engines for day-to-day work. The minority who were interested were European and Middle Eastern hauliers, and some options were available to them. Leyland’s market was in bread and butter fleet models, not exotic high powered makes to get you to Doha.
Finally on the TL12. I say operationally the TL12 was a great engine. You say it wasn’t. Okay, let’s agree to disagree and draw a line under the argument
gingerfold:
I’m really getting fed-up with all this going round in circles. I’ll have one last attempt to try and spell out big business management structures.Firstly the difference between Executive Chairman and non-Executive Chairman. Spurrier was the former with responsibility for day-to-day running of the business, Black was the latter, he chaired the monthly Board meeting. The Board comprised Executive Directors (Markland and Stokes for example), and non-Executive Directors, ‘captains of industry’ from other businesses that got well paid for attending a monthly Board meeting and advising the Executive Directors. As Managing Director of the entire British Leyland Group Stokes had complete autonomy in the day-to-day running of the entire business. To disagree with that is plainly wrong.
Fast forward to the Edwardes era and a few years before. The role of the NEB and its majority shareholding in British Leyland from the mid-1970s hasn’t been touched on, but undoubtedly, as BL was effectively nationalised Stokes’ role would not have been as dictatorial as previously. He had political issues to deal with. The run-down of AEC and Southall commenced in 1977 with the cessation of all the AEC truck models, except for the Marathon and some outstanding MoD orders that had to be fulfilled. Marathon production eventually transferred to Scammell. The closure of Southall WAS Stokes’ decision. No argument or doubt about it.
Michael Edwardes was appointed with the brief to sort out the car making decisions once and for all. That is where his main focus of attention was. He inherited the T45 project, started in 1974, and waved it through to completion. He approved the building of a new assembly factory at Leyland for the T45, which is where DAFs are assembled to this day. I have been on two factory tours in the last few years and they were very good and interesting.
The continual “rubbishing” of AEC engines and products. AEC was the second largest (after) Leyland commercial vehicle manufacturer in the UK. Like ALL vehicle builders that develops its own engines it had some failures over the years, but the vast majority of its output of 67 years was successful and well-liked by operators and drivers alike. Hundreds of operators at home and abroad, thousands of drivers. Were all these people wrong? I don’t think so.
As for the technical aspects of engine design. The vast majority of operators and purchasers through the decades have no interest in how, or why, an engine is designed (personally I do have some interest), but all the operator is concerned about is the reliability, the economy, the servicing and repair costs, the mileage run between overhauls, minimum downtime of the vehicle, whole-life running costs, and suitability for the work it has to do. If the engine has limited, or none, development potential for fitting in new models ten years hence is of no consequence to the operator. That is the province of the engine manufacturer and its design and development team. Another major consideration was, and is today, after-sales service and support.The mainstream AEC engines of the 1960s and 1970s, including the TL12, fulfilled all the required criteria of operators that bought them. The Leyland Group It had far more regional main depots and independent dealerships than any other UK manufacturer. The AEC after sales support was reckoned to be the best in the business and became the model for DAF, with several former AEC managers moving to DAF. Can you honestly say what the Diesel engine of 2030 will be? If there any new designs? Or will every new truck have an electric motor?
In the early and mid-1970s the UK maximum GVW was 32 tons; a 220 bhp engine was deemed perfectly adequate. Very few operators on standard UK general haulage and own-account work had any interest in more powerful engines for day-to-day work. The minority who were interested were European and Middle Eastern hauliers, and some options were available to them. Leyland’s market was in bread and butter fleet models, not exotic high powered makes to get you to Doha.
Finally on the TL12. I say operationally the TL12 was a great engine. You say it wasn’t. Okay, let’s agree to disagree and draw a line under the argument
Stokes WASN’T MD of Leyland Group at the time of the 691 and 760’s design stage.
The RUN DOWN of Southall COMMENCED in 1977 remind me what was Stoke’s position in the group at THAT point in time and who was MD.
Strange double standards you apply regarding Edwardes.He was MD but supposedly had no input over truck and bus while Stokes did.
Which part of,
Stokes over saw the design and production of your beloved TL12 not Edwardes and Edwardes wiped out AEC along with Leyland truck and bus division along with Rover and Triumph,
didn’t you understand.
The Crusader 280 and the Rolls 265 were also bread and butter motors.The difference is they had a reliable 400 hp and 100 lb/ft worth of potential contained within their basic architecture, unlike the TL12 and Edwardes knew it.The rest is history.
Seems to me you’ve got issues with Stokes while at the same time defending those where the real blame sits for this debacle.
Ironically now admiring the foreign competitor’s takeover of the domestic customer base turning us into an assembler of foreign components which was behind it all.
No surprise that the end result of all that is a business plan based on a 123 x 152 11 litre and 130 X 162 13 litre motor.
Edit 100 lb/ft per litre.
Carryfast:
Calculation what calculation.I’ve said piston speed isn’t an issue at truck engine speeds at well over 152 mm stroke let alone just that much.Engine speeds can obviously reduce to get the equivalent power output as leverage increases.
Haven’t got a clue what Anorak was referring to regarding 2 x BMEP or why he was referring to such a figure.
I thought he was referring to tensile loads on the piston and rod assembly which logically means peak power/max governed rpm between the exhaust and inlet strokes.Don’t ask me what it is in either case.If Anorak knows it then tell us.
Unless he’s going to tell us that the combined 14 main bearing fastenings aren’t going to amount to the need to contain a lot more tensile force applied by the pistons acting on them at peak torque rpm than the big end fastenings stopping the pistons and rods flying away from the crankshaft at peak power at 2,100 and 2,200 rpm respectively.
The same applies to the head fastenings stopping the head being blown off by the opposite force acting on it during the power stroke.Here’s a clue that’s more than 2 x BMEP.
Have you ever put any numbers to any of your statements? Try this: what is the tensile stress in the big end bolts of a TL12 at 2200rpm, under no load, at TDC, between the exhaust and compression strokes?
I have just read an article in the ‘letters’ section of Vintage Roadscene, May 2020. Extracts taken from the AEC gazette etc by folk involved. Probably not relevant to 'bore/stroke, crank throw etc though! It has probably been covered here previously, and Graham will know of them. Basically Stokes closed down AEC almost single handedly, he stopped any engine development, refused to permit AEC and Park Royal to go into production with the rear engine Routemaster. He also halted the supply of AEC engines to Willeme that resulted in them going into recievership. There are several other instances of his ‘dictatorship’ where he overuled committees and meetings that he was Chairman of, the meetings were very short and were purely to ‘rubber stamp’ decisions that he alone had already made! I have served on committees like those myself alas,
Later he also refused point blank to agree to UK vehicle weights being raised from 32 to 38 tonnes, this meant that Commer, Dodge, Ford and Bedford shelved the projects they had on their drawing boards for when the higher limit ‘might’ come in so effectively halted any development by UK makers. Of course when the restriction that Stokes had put on place was finally lifted the UK had nothing to hand, hence the Dutch, Germans and Swedes rapidly moved in. The article concludes that the pride of one man (Lord Stokes) was single-handely responsible for the demise of the UK heavy vehicle industry.
Pete.
[zb]
anorak:Carryfast:
Calculation what calculation.I’ve said piston speed isn’t an issue at truck engine speeds at well over 152 mm stroke let alone just that much.Engine speeds can obviously reduce to get the equivalent power output as leverage increases.
Haven’t got a clue what Anorak was referring to regarding 2 x BMEP or why he was referring to such a figure.
I thought he was referring to tensile loads on the piston and rod assembly which logically means peak power/max governed rpm between the exhaust and inlet strokes.Don’t ask me what it is in either case.If Anorak knows it then tell us.
Unless he’s going to tell us that the combined 14 main bearing fastenings aren’t going to amount to the need to contain a lot more tensile force applied by the pistons acting on them at peak torque rpm than the big end fastenings stopping the pistons and rods flying away from the crankshaft at peak power at 2,100 and 2,200 rpm respectively.
The same applies to the head fastenings stopping the head being blown off by the opposite force acting on it during the power stroke.Here’s a clue that’s more than 2 x BMEP.
Have you ever put any numbers to any of your statements? Try this: what is the tensile stress in the big end bolts of a TL12 at 2200rpm, under no load, at TDC, between the exhaust and compression strokes?
Have you had any dealings with the TL12 anorak and if so what were your thoughts?
Carryfast:
[zb]
anorak:Carryfast:
…
Yet you still say that Stokes was the main player in the destruction of AEC and with it Leyland Truck and Bus division.Not Edwardes.Strange.Have you read Edwardes’ autobiography?
No I wouldn’t want to read his lies…
How do you know he’s lying, if you don’t know what he has said?
ramone:
[zb]
anorak:
Have you had any dealings with the TL12 anorak and if so what were your thoughts?
Only what I have read, IE that it was competitive for reliability and fuel consumption, with anything else at the time. Lots of things Leyland did were ■■■■-ups, but the TL12 sailed through that storm with its reputation intact. It’s a shame they never got round to doing an intercooled version. Perhaps someone on here could experiment with that? It would not take much work to fit a charge cooler off another make of lorry to a Roadtrain, then fiddle with the pump to increase the fuel flow rate.
Carryfast, you would make a great tabloid newspaper editor, you would be very good at editing a ten thousand word article down to a sentence that suits your agenda.
You’ve been told numerous times, by people that know, that owing to the lack of funds thanks to the ailing car division the engineers hands were basically tied behind their backs, they had to use what they had, this includes tooling, so the TL12 was pretty much their only option.
Was it the best engine available? No, but both in testing and real world road haulage it did very well.
Stokes was the man behind the truck and bus division’s downfall, people that were actually there confirmed this and that is why everyone here is singing from the same song sheet on that, you however have a different version of events because you sat in the tea room at Scammell. You really are hilarious, keep up the good work.
Carryfast:
gingerfold:
I’m really getting fed-up with all this going round in circles. I’ll have one last attempt to try and spell out big business management structures.Firstly the difference between Executive Chairman and non-Executive Chairman. Spurrier was the former with responsibility for day-to-day running of the business, Black was the latter, he chaired the monthly Board meeting. The Board comprised Executive Directors (Markland and Stokes for example), and non-Executive Directors, ‘captains of industry’ from other businesses that got well paid for attending a monthly Board meeting and advising the Executive Directors. As Managing Director of the entire British Leyland Group Stokes had complete autonomy in the day-to-day running of the entire business. To disagree with that is plainly wrong.
Fast forward to the Edwardes era and a few years before. The role of the NEB and its majority shareholding in British Leyland from the mid-1970s hasn’t been touched on, but undoubtedly, as BL was effectively nationalised Stokes’ role would not have been as dictatorial as previously. He had political issues to deal with. The run-down of AEC and Southall commenced in 1977 with the cessation of all the AEC truck models, except for the Marathon and some outstanding MoD orders that had to be fulfilled. Marathon production eventually transferred to Scammell. The closure of Southall WAS Stokes’ decision. No argument or doubt about it.
Michael Edwardes was appointed with the brief to sort out the car making decisions once and for all. That is where his main focus of attention was. He inherited the T45 project, started in 1974, and waved it through to completion. He approved the building of a new assembly factory at Leyland for the T45, which is where DAFs are assembled to this day. I have been on two factory tours in the last few years and they were very good and interesting.
The continual “rubbishing” of AEC engines and products. AEC was the second largest (after) Leyland commercial vehicle manufacturer in the UK. Like ALL vehicle builders that develops its own engines it had some failures over the years, but the vast majority of its output of 67 years was successful and well-liked by operators and drivers alike. Hundreds of operators at home and abroad, thousands of drivers. Were all these people wrong? I don’t think so.
As for the technical aspects of engine design. The vast majority of operators and purchasers through the decades have no interest in how, or why, an engine is designed (personally I do have some interest), but all the operator is concerned about is the reliability, the economy, the servicing and repair costs, the mileage run between overhauls, minimum downtime of the vehicle, whole-life running costs, and suitability for the work it has to do. If the engine has limited, or none, development potential for fitting in new models ten years hence is of no consequence to the operator. That is the province of the engine manufacturer and its design and development team. Another major consideration was, and is today, after-sales service and support.The mainstream AEC engines of the 1960s and 1970s, including the TL12, fulfilled all the required criteria of operators that bought them. The Leyland Group It had far more regional main depots and independent dealerships than any other UK manufacturer. The AEC after sales support was reckoned to be the best in the business and became the model for DAF, with several former AEC managers moving to DAF. Can you honestly say what the Diesel engine of 2030 will be? If there any new designs? Or will every new truck have an electric motor?
In the early and mid-1970s the UK maximum GVW was 32 tons; a 220 bhp engine was deemed perfectly adequate. Very few operators on standard UK general haulage and own-account work had any interest in more powerful engines for day-to-day work. The minority who were interested were European and Middle Eastern hauliers, and some options were available to them. Leyland’s market was in bread and butter fleet models, not exotic high powered makes to get you to Doha.
Finally on the TL12. I say operationally the TL12 was a great engine. You say it wasn’t. Okay, let’s agree to disagree and draw a line under the argument
Stokes WASN’T MD of Leyland Group at the time of the 691 and 760’s design stage.
The RUN DOWN of Southall COMMENCED in 1977 remind me what was Stoke’s position in the group at THAT point in time and who was MD.
Strange double standards you apply regarding Edwardes.He was MD but supposedly had no input over truck and bus while Stokes did.
Which part of,
Stokes over saw the design and production of your beloved TL12 not Edwardes and Edwardes wiped out AEC along with Leyland truck and bus division along with Rover and Triumph,
didn’t you understand.The Crusader 280 and the Rolls 265 were also bread and butter motors.The difference is they had a reliable 400 hp and 100 lb/ft worth of potential contained within their basic architecture, unlike the TL12 and Edwardes knew it.The rest is history.
Seems to me you’ve got issues with Stokes while at the same time defending those where the real blame sits for this debacle.
Ironically now admiring the foreign competitor’s takeover of the domestic customer base turning us into an assembler of foreign components which was behind it all.
No surprise that the end result of all that is a business plan based on a 123 x 152 11 litre and 130 X 162 13 litre motor.
I have never written that Stokes was MD in 1962 when the A691 / A760 was in the design stage. Markland signed-off the project as I have said on numerous occasions. It must really have hurt Stokes to approve the TL12 development based on the AV760, but even he realised that there wasn’t another group engine suitable.
Don Ryder took over the running of BL at nationalisation in 1975. By then everyone had realised how useless Stokes was as a Chief Executive, but in his new position as Non-Executive President he still had advisory powers. Stokes hated AEC because even as the “super-salesman” he had lost out on numerous occasions in competitive negotiations with customers and potential customers who placed orders with AEC. He tolerated senior AEC people such as Bob Fryars because even Stokes realised that there wasn’t anyone on the Leyland (including Scammell and Albion) team with Bob Fryars’ expertise and skills. Stokes had served an engineering apprenticeship so he had some technical knowledge. When Fryars took over as Group Chief Engineer the Leyland engineering team was young and inexperienced. Even dyed in the wool Leyland people acknowledge that Stokes had one aim in life with regards to AEC - that was to close Southall down, an aim that he finally achieved, whether he was running the company or not. I don’t believe in coincidences, so Stokes retired in 1979, just when Southall closed for good. Now, how strange is that?
I’m currently reading a newly published book about the RR Merlin engine. Now then CF, what did Mr Royce do wrong when he designed that engine?
[zb]
anorak:
Have you ever put any numbers to any of your statements? Try this: what is the tensile stress in the big end bolts of a TL12 at 2200rpm, under no load, at TDC, between the exhaust and compression strokes?
You do know that the inlet stroke starts at around TDC after the exhaust stroke the compression stroke starts at around BDC like the exhaust stroke.
It’s obvious that it just ain’t going to get any more than at TDC between exhaust and inlet strokes at max gorverned engine speed under load or not.
You didn’t answer the question why are main bearing and head fastenings much stronger than big end bearing fastenings.The latter being all that’s stopping the piston and rod assembly going flying away from the crankshaft and under the most tension at which point and engine speed ?.
So WTF has 2 x BMEP got to do with it.
It’s obvious that the tensile strength of the big end bearing cap fastenings will need to have a significant margin over over the kinetic energy contained in the piston and rod at max engine speed during the deceleration for the change over between the exhaust and inlet strokes IE massive deceleration followed by massive acceleration.That’s the max possible tensile load on the piston and rod assembly.
That margin doesn’t get close to the margin you’ll need in the main bearing and head fastenings to contain the compressive loadings between piston/rod assembly and the cylinder head during the power stroke at peak torque or for that matter peak power obviously at full load.
That’s why blown up MX engines with broken big end fastenings aren’t littering the junk yards.
Also no surprise AEC rightly didn’t have the bottle to boost the TL12 to 100 lb/ft per litre + with an intercooler.
Carryfast:
[zb]
anorak:
Have you ever put any numbers to any of your statements? Try this: what is the tensile stress in the big end bolts of a TL12 at 2200rpm, under no load, at TDC, between the exhaust and compression strokes?You do know that the inlet stroke starts at around TDC after the exhaust stroke the compression stroke starts at around BDC like the exhaust stroke.
It’s obvious that it just ain’t going to get any more than at TDC between exhaust and inlet strokes at max gorverned engine speed under load or not.
You didn’t answer the question why are main bearing and head fastenings much stronger than big end bearing fastenings.The latter being all that’s stopping the piston and rod assembly going flying away from the crankshaft and under the most tension at which point and engine speed ?.
So WTF has 2 x BMEP got to do with it.It’s obvious that the tensile strength of the big end bearing cap fastenings will need to have a significant margin over over the kinetic energy contained in the piston and rod at max engine speed during the deceleration for the change over between the exhaust and inlet strokes IE massive deceleration followed by massive acceleration.That’s the max possible tensile load on the piston and rod assembly.
That margin doesn’t get close to the margin you’ll need in the main bearing and head fastenings to contain the compressive loadings between piston/rod assembly and the cylinder head during the power stroke at peak torque or for that matter peak power obviously at full load.That’s why blown up MX engines with broken big end fastenings aren’t littering the junk yards.
Also no surprise AEC rightly didn’t have the bottle to boost the TL12 to 100 lb/ft per litre + with an intercooler.
^^^Laughable piffle. How many accelerations are there? LOLOL.
[zb]
anorak:Carryfast:
[zb]
anorak:
Have you ever put any numbers to any of your statements? Try this: what is the tensile stress in the big end bolts of a TL12 at 2200rpm, under no load, at TDC, between the exhaust and compression strokes?You do know that the inlet stroke starts at around TDC after the exhaust stroke the compression stroke starts at around BDC like the exhaust stroke.
It’s obvious that it just ain’t going to get any more than at TDC between exhaust and inlet strokes at max gorverned engine speed under load or not.
You didn’t answer the question why are main bearing and head fastenings much stronger than big end bearing fastenings.The latter being all that’s stopping the piston and rod assembly going flying away from the crankshaft and under the most tension at which point and engine speed ?.
So WTF has 2 x BMEP got to do withIt’s obvious that the tensile strength of the big end bearing cap fastenings will need to have a significant margin over over the kinetic energy contained in the piston and rod at max engine speed during the deceleration for the change over between the exhaust and inlet strokes IE massive deceleration followed by massive acceleration.That’s the max possible tensile load on the piston and rod assembly.
That margin doesn’t get close to the margin you’ll need in the main bearing and head fastenings to contain the compressive loadings between piston/rod assembly and the cylinder head during the power stroke at peak torque or for that matter peak power obviously at full load.That’s why blown up MX engines with broken big end fastenings aren’t littering the junk yards.
Also no surprise AEC rightly didn’t have the bottle to boost the TL12 to 100 lb/ft per litre + with an intercooler.^^^Laughable piffle. How many accelerations are there? LOLOL.
The MX engine gets a mention now ffs.
windrush:
I have just read an article in the ‘letters’ section of Vintage Roadscene, May 2020. Extracts taken from the AEC gazette etc by folk involved. Probably not relevant to 'bore/stroke, crank throw etc though! It has probably been covered here previously, and Graham will know of them. Basically Stokes closed down AEC almost single handedly, he stopped any engine development, refused to permit AEC and Park Royal to go into production with the rear engine Routemaster. He also halted the supply of AEC engines to Willeme that resulted in them going into recievership. There are several other instances of his ‘dictatorship’ where he overuled committees and meetings that he was Chairman of, the meetings were very short and were purely to ‘rubber stamp’ decisions that he alone had already made! I have served on committees like those myself alas,Later he also refused point blank to agree to UK vehicle weights being raised from 32 to 38 tonnes, this meant that Commer, Dodge, Ford and Bedford shelved the projects they had on their drawing boards for when the higher limit ‘might’ come in so effectively halted any development by UK makers. Of course when the restriction that Stokes had put on place was finally lifted the UK had nothing to hand, hence the Dutch, Germans and Swedes rapidly moved in. The article concludes that the pride of one man (Lord Stokes) was single-handely responsible for the demise of the UK heavy vehicle industry.
Pete.
I read that Pete , in fact there was an article on AEC in one of the monthly vintage magazines again which came out with some pretty damning assumptions regarding Stokes and a few of his colleagues , there are a lot of people out there telling the same story , obviously all are wrong
When Volvo started selling tractor units in Britain they offered the F86 and F88 , now i would guess the F86 at that time would be rated around 192bhp and the F88 at 240 bhp. Now anyone with a brain cell to their name would know that a 6.7 litre engine pushing out 192 bhp wouldn`t last 2 minutes or a 9.6 litre engine pushing out 240 bhp would either. Does anyone know what gross weights these motors would have been operating at in Sweden. I do know that the 1972 F86 my dad drove had a design weight of 36 tons. In hindsight we could have halted this madness and saved Volvo from bankruptcy . 
newmercman:
Carryfast, you would make a great tabloid newspaper editor, you would be very good at editing a ten thousand word article down to a sentence that suits your agenda.You’ve been told numerous times, by people that know, that owing to the lack of funds thanks to the ailing car division the engineers hands were basically tied behind their backs, they had to use what they had, this includes tooling, so the TL12 was pretty much their only option.
Was it the best engine available? No, but both in testing and real world road haulage it did very well.
Stokes was the man behind the truck and bus division’s downfall, people that were actually there confirmed this and that is why everyone here is singing from the same song sheet on that, you however have a different version of events because you sat in the tea room at Scammell. You really are hilarious, keep up the good work.
Strange in that case how you said yourself that bringing Rolls in house and putting it in the Roadtrain before launch was a better idea than launching it with th option of TL12 take it or leave it.
The circumstances of the V8 fiasco before that suggests that AEC’s designers really were applying F1 race car engine design ideas to truck engines.Nothing to do with the fact that no one was throwing any cash their way to do it.Obviously the Routeamaster motor’s stroke would look more than enough to them, if they’d thought that 114 mm was enough, what could possibly go wrong.
It was Stokes who had no funds to fix their zb ups.So yes the TL12 was Leyland’s only option.
Remind me again why putting the Rolls in the Roadtrain wouldn’t have fixed that and why Rolls wasn’t brought in house to do it and when Stokes left the role of MD of Leyland Group and then retired.Bearing in mind the T45’s design stage and launch dates.
The fact is Stokes had no influence on what was going on at AEC or Leyland as a whole much before 1965 and certainly not after 1975.His only crime was putting the TL12 in the Marathon. Which the AEC fans tell us was a good thing.
Edwardes ran down AEC and then closed it.
While making sure that the Roadtrain was crippled with the TL12 at launch to keep his handlers in the government happy.Who were self admittedly committed to wiping us out as a manufacturing based economy to the obvious benefit of our foreign competitors.