Carryfast:
Some say the Mack V8’s design played a part in Scania’s design but even that is unlikely.
Is true. Try doing a bit of research.
Carryfast:
The fact that both the MX 11 and the 15 litre ■■■■■■■ ISX went for smaller bore sizes than their DK and N14 predecessors respectively and even the MX13 didn’t increase bore size over the 11.6 DK’s is a clue.
Higher cylinder pressures in the later engines. Hoop stress in the liner inversely proportional to bore.
Edit- what a fool I am- the hoop stress is proportional to the bore, possibly explaining the reduction in bore as cyl pressures have increased over the years. That is what I meant.
Carryfast:
The fact that both the MX 11 and the 15 litre ■■■■■■■ ISX went for smaller bore sizes than their DK and N14 predecessors respectively and even the MX13 didn’t increase bore size over the 11.6 DK’s is a clue.
Higher cylinder pressures in the later engines. Hoop stress in the liner inversely proportional to bore.
Which makes the case for L12/TL12 v Rolls Eagle or TD120 or even DKS how.Either way we know the L12’s/TL12’s specific torque output couldn’t cut it.
Obviously cylinder pressures and/or resulting loading on the small end/con rod/big end needing to be proportionally higher as leverage at the crank decreases for equivalent torque output and obviously the former not being more than offset by the greater piston area.
From a quick glance it seems that the TL12 Marathon 2 acquitted itself very well in the road test, having participated in such road tests myself I can guarantee their accuracy in comparison to each other. The lorry with a TL12 was a fast motor over the course in comparison with its peers, including the supposedly superior E290, it’s there in black and white for all to see, regardless of crank leverage or the new I’m going to try to sound clever phrase ‘engine architecture.’ However let’s not let facts get in the way of an argument.
I was a little surprised at how well the RR265 performed in the tests, you got a lot of bang for your buck with one of those, I drove a 401 with one in it for a couple of days and it made no impression on me at all, apart from how noisy it was, a nice noise, but a lot of it.
To finish, the late arrival of the term “boat anchor” has cost me a fiver, I had a bet with myself that it would appear much sooner in this thread.
ramone:
Thanks for posting those Dean , it just goes to show what a terrible unfit for purpose engine the TL12 was. It may have completed the course with a higher average speed and went up the hills slightly faster but hey ho that means nothing. The E290 needed to be driven carefully to get the best out of it and that’s what the testers did. It was higher geared to keep the mpg figures looking good at the expense of uphill speed. Don’t get me wrong the E290 was a very good engine but so was the TL12 . The stats don’t lie , no doubt a conspiracy theory will be in the pipeline. 14 litre E290 12.47 litre AEC TL12
The 14 litre ■■■■■■■ wasn’t at its best at such low outputs who would have thought it.
Your stats don’t look so good when the marketing department sends you a memo asking for a 300 hp + version of your 12.5 litre boat anchor to match the Rolls or DKS or F12 or ■■■■■■■ 320.
Or in the case of the Buffalo the customer walks away when the insult of a 12.5 litre motor with less than 600 lbft is added to the injury of the 500.
No problem we’re going with a production life of only around 5 years at most we’ll just make another motor that’s up to the job when the time comes.
Then people ask why Leyland failed.Blame it on the workers it was their fault.
Well if the marketing dept asked for a 300bhp+ unit i would tell them to stick to marketing because i run transport they market , but if they wanted a 300bhp + motor they wouldn’t have looked at the Marathon in the first place. Now you keep banging on about your new hero the TD120 , well that was 60bhp up on the TL and ■■■■■■■ so the TL would have faired better than the ■■■■■■■ because the test results dont lie. Put the TL against the 220 ■■■■■■■ or Rolls and it would be a much better option because it produced much more power. So put the TL or E290 against
engines with similar output and you have a level playing ground . How would a TD120 compare to a V8 Scania that produced 60 bhp more.
The TL12 was a boat anchor so what would that make the E290 which was slower but only marginally . Two very good engines .
BL were thinking on the right lines offering in house engines in their vehicles where they went wrong was not producing a new engine to cover impending weight increases. They instead did the opposite to every surviving manufacturer in europe and went down the buying in road .
newmercman:
From a quick glance it seems that the TL12 Marathon 2 acquitted itself very well in the road test, having participated in such road tests myself I can guarantee their accuracy in comparison to each other. The lorry with a TL12 was a fast motor over the course in comparison with its peers, including the supposedly superior E290, it’s there in black and white for all to see, regardless of crank leverage or the new I’m going to try to sound clever phrase ‘engine architecture.’ However let’s not let facts get in the way of an argument.
I was a little surprised at how well the RR265 performed in the tests, you got a lot of bang for your buck with one of those, I drove a 401 with one in it for a couple of days and it made no impression on me at all, apart from how noisy it was, a nice noise, but a lot of it.
To finish, the late arrival of the term “boat anchor” has cost me a fiver, I had a bet with myself that it would appear much sooner in this thread.
I think Graham mentioned on another thread that the TL 12 had been developed to produce around 320bhp but it never went into production instead they made the decision to buy in , this was at a time when SA ERF and Foden were still their real competion and to gain sales they offered the same or similar drivetrain
The boat anchor comment was long overdue but expected
newmercman:
From a quick glance it seems that the TL12 Marathon 2 acquitted itself very well in the road test, having participated in such road tests myself I can guarantee their accuracy in comparison to each other. The lorry with a TL12 was a fast motor over the course in comparison with its peers, including the supposedly superior E290, it’s there in black and white for all to see, regardless of crank leverage or the new I’m going to try to sound clever phrase ‘engine architecture.’ However let’s not let facts get in the way of an argument.
I was a little surprised at how well the RR265 performed in the tests, you got a lot of bang for your buck with one of those, I drove a 401 with one in it for a couple of days and it made no impression on me at all, apart from how noisy it was, a nice noise, but a lot of it.
To finish, the late arrival of the term “boat anchor” has cost me a fiver, I had a bet with myself that it would appear much sooner in this thread.
I think Graham mentioned on another thread that the TL 12 had been developed to produce around 320bhp but it never went into production instead they made the decision to buy in , this was at a time when SA ERF and Foden were still their real competion and to gain sales they offered the same or similar drivetrain
The boat anchor comment was long overdue but expected
Yes there was an intercooled version of the TL12 producing 320 bhp on the test bed, whether any were ever fitted in the T45 Roadtrain is uncertain, although I’m certain I did see a 320 badged Roadtrain.
As for boat anchor, I now prefer the term “crank leverage”, or “leverage at the crank”, although I’m not exactly sure what type of crank it is describing. It might be the poster who coined the term describing himself?
The roadtrain had alot of different engine options over its life,but dont think i have anything on a TL12 320 bhp in one. The ■■■■■■■ 320 was fitted
in alot of them as well as Perkins Eagle 325 bhp,and,Rolls Royce 265,290’s and 350’s.
You may find this article about the Marathon intresting as it has alot of info about the AEC / Leyland engines.
ramone:
Well if the marketing dept asked for a 300bhp+ unit i would tell them to stick to marketing because i run transport they market , but if they wanted a 300bhp + motor they wouldn’t have looked at the Marathon in the first place. Now you keep banging on about your new hero the TD120 , well that was 60bhp up on the TL and ■■■■■■■ so the TL would have faired better than the ■■■■■■■ because the test results dont lie. Put the TL against the 220 ■■■■■■■ or Rolls and it would be a much better option because it produced much more power. So put the TL or E290 against
engines with similar output and you have a level playing ground . How would a TD120 compare to a V8 Scania that produced 60 bhp more.
The TL12 was a boat anchor so what would that make the E290 which was slower but only marginally . Two very good engines .
BL were thinking on the right lines offering in house engines in their vehicles where they went wrong was not producing a new engine to cover impending weight increases. They instead did the opposite to every surviving manufacturer in europe and went down the buying in road .
Remind me why customers bought the NA L12 not the TL12.
Here’s another clue the 290 was a derated version of the ■■■■■■■■■■ wasn’t it’s all out capability as we know.Like the small cam it was quite capable of a 400 hp output.
BL were thinking along the lines of in house engine production but they didn’t have an in house engine up to the job in their armoury.Because AEC were more into making bus engines than truck engines and that’s what ultimately helped to put Leyland out of the frame.
The fact is the TL12 was obsolete when it was introduced.
That and the fact that DAF had obvious designs on taking over its market share with the help of our treacherous government.
All of your laughable moving of goal posts to make the TL12 look good won’t fix that.
newmercman:
From a quick glance it seems that the TL12 Marathon 2 acquitted itself very well in the road test, having participated in such road tests myself I can guarantee their accuracy in comparison to each other. The lorry with a TL12 was a fast motor over the course in comparison with its peers, including the supposedly superior E290, it’s there in black and white for all to see, regardless of crank leverage or the new I’m going to try to sound clever phrase ‘engine architecture.’ However let’s not let facts get in the way of an argument.
I was a little surprised at how well the RR265 performed in the tests, you got a lot of bang for your buck with one of those, I drove a 401 with one in it for a couple of days and it made no impression on me at all, apart from how noisy it was, a nice noise, but a lot of it.
To finish, the late arrival of the term “boat anchor” has cost me a fiver, I had a bet with myself that it would appear much sooner in this thread.
I think Graham mentioned on another thread that the TL 12 had been developed to produce around 320bhp but it never went into production instead they made the decision to buy in , this was at a time when SA ERF and Foden were still their real competion and to gain sales they offered the same or similar drivetrain
The boat anchor comment was long overdue but expected
Yes there was an intercooled version of the TL12 producing 320 bhp on the test bed, whether any were ever fitted in the T45 Roadtrain is uncertain, although I’m certain I did see a 320 badged Roadtrain.
As for boat anchor, I now prefer the term “crank leverage”, or “leverage at the crank”, although I’m not exactly sure what type of crank it is describing. It might be the poster who coined the term describing himself?
I had leverage at my crank a few years back G,it took several visits to the physiotherapist to clear it up,nasty!
gingerfold:
Yes there was an intercooled version of the TL12 producing 320 bhp on the test bed, whether any were ever fitted in the T45 Roadtrain is uncertain, although I’m certain I did see a 320 badged Roadtrain.
As for boat anchor, I now prefer the term “crank leverage”, or “leverage at the crank”, although I’m not exactly sure what type of crank it is describing. It might be the poster who coined the term describing himself?
We know that there was never any 320 hp TL12 powered Roadtrian they could have tested it at 750 hp on the dyno for all it mattered to being signed off for production.
But there were plenty of 300 hp + Rolls and ■■■■■■■ versions.
Leverage as in force x distance of the crank pin centre line from the crank shaft centre line = more torque at the flywheel = more power at any given engine speed at any equivalent cylinder pressure and/or force on the piston and con rod assembly.
Some rightly call call it free power both in terms of durability and fuel consumption.
DEANB:
The roadtrain had alot of different engine options over its life,but dont think i have anything on a TL12 320 bhp in one. The ■■■■■■■ 320 was fitted
in alot of them as well as Perkins Eagle 325 bhp,and,Rolls Royce 265,290’s and 350’s.
You may find this article about the Marathon intresting as it has alot of info about the AEC / Leyland engines.
Click on twice to read.
4
3
2
1
0
Thanks for posting Dean , the shortcomings of the first Marathons highlighted but the TL12 gets a glowing report , obviously they didn’t know it was a boat anchor
As you read the reports of this engine and the various chassis it was fitted to it makes me very annoyed to think that with the right development etc Leyland had the makings of a very good product,what might have been ■■?.
ramone:
the TL12 gets a glowing report , obviously they didn’t know it was a boat anchor
Obviously they’re following the same old strikes wot dun it agenda and narrative.
Don’t let facts, like unwanted laughable poverty spec front wheel drive junk cars, replacing attractive IRS Triumph saloons with ugly, live axle Rovers and truck engines limited by their bus design limitations, get in the way of a narrative that’s obviously meant to divert attention from any suggestion that the firm was deliberately run onto the rocks to the advantage of the foreign competition.
If the TL12 was capable of 300 + hp that option would have been offered from the start like the DAF DKS and the Rolls 305 and ■■■■■■■ 335 - 400 and Volvo TD120.
They all obviously saw the need for it and had the designs to meet it.The rest is history.
Stillgame:
As you read the reports of this engine and the various chassis it was fitted to it makes me very annoyed to think that with the right development etc Leyland had the makings of a very good product,what might have been ■■?.
There’s not an objective ‘report’ out there that could possibly make the L12/TL12 a contender v the Rolls Eagle, TD120, or DAF DK.It was never going to happen without another foreseeable debacle to add to the AEC V8 and the Leyland 500.That’s why an intercooled version of it didn’t get past the Dyno stage and it’s why the L12 couldn’t even match the Rolls 220.
It would have taken a totally new engine design needing a totally new block design when Leyland and the government had already made the decision to close the doors on the UK manufacturing sector.
Stillgame:
As you read the reports of this engine and the various chassis it was fitted to it makes me very annoyed to think that with the right development etc Leyland had the makings of a very good product,what might have been ■■?.
There’s not an objective ‘report’ out there that could possibly make the L12/TL12 a contender v the Rolls Eagle, TD120, or DAF DK.It was never going to happen without another foreseeable debacle to add to the AEC V8 and the Leyland 500.That’s why an intercooled version of it didn’t get past the Dyno stage and it’s why the L12 couldn’t even match the Rolls 220.
It would have taken a totally new engine design needing a totally new block design when Leyland and the government had already made the decision to close the doors on the UK manufacturing sector.
The TL was more than a match for like for like engines ie same power output . The Daf i see is now thrown into the equation , if you pitch a 280 Daf then they are comparable , put a F10 in there they too are around the same output but you don’t seem to be able to do that. Put the Daf and Volvo against say a 480 turbostar and tell me how they compare . Well they dont because ir’s a different catogary.
Put the unreliable Rolls 220 against the AV760 with similar power . Put the 205 ■■■■■■■ against the L12 i dont think the 205 was still being produced when the L12 was launched. Put the 201 Gardner against the L12 . Hell it’s not rocket science … maybe it is to some !
ramone:
the TL12 gets a glowing report , obviously they didn’t know it was a boat anchor
Obviously they’re following the same old strikes wot dun it agenda and narrative.
Don’t let facts, like unwanted laughable poverty spec front wheel drive junk cars, replacing attractive IRS Triumph saloons with ugly, live axle Rovers and truck engines limited by their bus design limitations, get in the way of a narrative that’s obviously meant to divert attention from any suggestion that the firm was deliberately run onto the rocks to the advantage of the foreign competition.
If the TL12 was capable of 300 + hp that option would have been offered from the start like the DAF DKS and the Rolls 305 and ■■■■■■■ 335 - 400 and Volvo TD120.
They all obviously saw the need for it and had the designs to meet it.The rest is history.
The TL was never a bus engine neither was the L12 , i always thought the TL should have been it would have made a great rear engined Reliance but it never happened , leaving Leyland the chance to give Volvo their whole bus technology and their foothold into the nations double decker bus market , which they did. Instead of seeing Atlanteans or wgatever , we now see Volvos
Carryfast:
There’s not an objective ‘report’ out there that could possibly make the L12/TL12 a contender v the Rolls Eagle, TD120, or DAF DK.It was never going to happen without another foreseeable debacle to add to the AEC V8 and the Leyland 500.That’s why an intercooled version of it didn’t get past the Dyno stage and it’s why the L12 couldn’t even match the Rolls 220.
It would have taken a totally new engine design needing a totally new block design when Leyland and the government had already made the decision to close the doors on the UK manufacturing sector.
The TL was more than a match for like for like engines ie same power output . The Daf i see is now thrown into the equation , if you pitch a 280 Daf then they are comparable , put a F10 in there they too are around the same output but you don’t seem to be able to do that. Put the Daf and Volvo against say a 480 turbostar and tell me how they compare . Well they dont because ir’s a different catogary.
Put the unreliable Rolls 220 against the AV760 with similar power . Put the 205 ■■■■■■■ against the L12 i dont think the 205 was still being produced when the L12 was launched. Put the 201 Gardner against the L12 . Hell it’s not rocket science … maybe it is to some !
You want to ignore the DAF DKS because your 12.5 litre motor can’t match it. Same with the TD120.Then people moan about the Brits burying their heads in the sand regarding the foreign competition.
You compare engines on their capacity and their specific output.In the case of truck engines if your competition has an engine of equivalent, let alone less, capacity that puts out more torque than your best shot then you’ve got a problem.A big problem in Leyland’s case because it didn’t have the cash or the inclination to fix it.
As for the ‘unreliable’ Rolls.A supposedly inherently unreliable 12.1 litre motor that, unlike the TL12, went on to give a ‘reliable’ 1,200 + lb/ft torque and 350-400 hp from almost 1/2 a litre less.
ramone:
the TL12 gets a glowing report , obviously they didn’t know it was a boat anchor
Obviously they’re following the same old strikes wot dun it agenda and narrative.
Don’t let facts, like unwanted laughable poverty spec front wheel drive junk cars, replacing attractive IRS Triumph saloons with ugly, live axle Rovers and truck engines limited by their bus design limitations, get in the way of a narrative that’s obviously meant to divert attention from any suggestion that the firm was deliberately run onto the rocks to the advantage of the foreign competition.
If the TL12 was capable of 300 + hp that option would have been offered from the start like the DAF DKS and the Rolls 305 and ■■■■■■■ 335 - 400 and Volvo TD120.
They all obviously saw the need for it and had the designs to meet it.The rest is history.
The TL was never a bus engine neither was the L12
You seem to have missed the point that, according to cav’s more than credible previous comments, it was the limitations imposed by the AEC block design’s bus engine origins that stopped them bolting a 6 inch + throw crankshaft into it.
Now awaits the 590 and 690 were never bus engines.
Carryfast:
There’s not an objective ‘report’ out there that could possibly make the L12/TL12 a contender v the Rolls Eagle, TD120, or DAF DK.It was never going to happen without another foreseeable debacle to add to the AEC V8 and the Leyland 500.That’s why an intercooled version of it didn’t get past the Dyno stage and it’s why the L12 couldn’t even match the Rolls 220.
It would have taken a totally new engine design needing a totally new block design when Leyland and the government had already made the decision to close the doors on the UK manufacturing sector.
The TL was more than a match for like for like engines ie same power output . The Daf i see is now thrown into the equation , if you pitch a 280 Daf then they are comparable , put a F10 in there they too are around the same output but you don’t seem to be able to do that. Put the Daf and Volvo against say a 480 turbostar and tell me how they compare . Well they dont because ir’s a different catogary.
Put the unreliable Rolls 220 against the AV760 with similar power . Put the 205 ■■■■■■■ against the L12 i dont think the 205 was still being produced when the L12 was launched. Put the 201 Gardner against the L12 . Hell it’s not rocket science … maybe it is to some !
You want to ignore the DAF DKS because your 12.5 litre motor can’t match it. Same with the TD120.Then people moan about the Brits burying their heads in the sand regarding the foreign competition.
You compare engines on their capacity and their specific output.In the case of truck engines if your competition has an engine of equivalent, let alone less, capacity that puts out more torque than your best shot then you’ve got a problem.A big problem in Leyland’s case because it didn’t have the cash or the inclination to fix it.
As for the ‘unreliable’ Rolls.A supposedly inherently unreliable 12.1 litre motor that, unlike the TL12, went on to give a ‘reliable’ 1,200 + lb/ft torque and 350-400 hp from almost 1/2 a litre less.
So what if your requirements were for an engine up to 280 bhp , and when the TL was launched and up to it being discontinued 280 was firstly regarded as a high powered engine and at the end '81 levelling out to be the average output for the British market .Was it the engine that was highly regarded’s fault BL didn’t have the cash to develop it . I think not. As for the Daf it was nothing spectacular at 280 absolutely dreadful at 310 because i drove both . The 350 was a good motor but the 360 Turbostars were just as good if not better
