ramone:
So answer the question , what problems did the TL12 pose for operators while in service , was it poor on fuel ,did it prove troublesome in service and was its performance on the road not up to scratch.■■?
There are references out there to it having a penchant for piston breakages ? ( maybe as expected of a design based on the premise of trading leverage at the crank for more force at the piston ? ).That at around less than just 65 lb/ft per litre.Which leaves the question of what stopped the supposed after cooled 325 hp version in its tracks and what made Leyland drop the thing shortly after going to all the trouble of transferring production of it from AEC to Leyland ?.In favour of just using ■■■■■■■ and Rolls ?.Bearing in mind I don’t buy after cooling being too much to get their heads around in the day or cost.
So yes maybe just about good enough in service by the standards of the day but a disaster for Leyland’s in house engine manufacturing business model.In not having the necessary redundancy for development built in of the Rolls and ■■■■■■■■■■ the form of the required leverage at the crank.
Which leaves the question of the AEC V8.Which its own designers seem to have rightly disowned as being a lemon in them wanting it shelved ?.
So it doesnt fit with your theory, so tell us about piston breakages , not a well known fact and something i havent heard on here , so who were the hauliers that had trouble with the aforementioned breakdowns were they a regular occurence ■■?
I’ve never heard of a TL12 piston breakage problem and no one else on the Marathon thread has mentioned it either. But I do know of a RR Eagle 220 that caused me a load of grief one day.
It was in that glorious summer of 1976 and I was a Shift Manager at Mothers Pride Bakery Wigan, which had just been expanded to produce over 9,000 loaves per hour across three lines of plant, two of which were fully automated. Now an automated bread production line uses plenty of compressed air for transferring bread tins between the various sections of the process and the newly installed bakery high speed compressors were proving troublesome and they were being repaired. So a mobile compressor had been brought in to provide compressed air and it was driven by a RR Eagle 220, identical to the one in the photo on the Marathon thread. During that summer, with the heat of the ovens and the heat outside, the internal bakery temperature was around 35 degrees C and production was in trouble because of the excessive temperatures that meant that the dough was very difficult to keep under control. Any slight stoppages in the process because of machinery problems caused even more problems. I had just finished my early shift at 2.00 pm one Sunday and as I walked out of the bakery to the car park I had to go past the RR powered compressor. As soon as I saw it I was horrified to see clouds of steam issuing from the radiator and before I could do anything about it, as I stood there staring at it, it seized up solid with a loud bang that didn’t sound at all good. With the compressed air reservoirs emptied in a couple of minutes the two fully automated production lines shut down; the equivalent of over 4 tons of unbaked, and uncontrollable, dough was in the system, and 3,500 loaves baking in the ovens. I was at the bakery for the remainder of the day helping to sort out the problems and the mess from all that dough is indescribable. By the time we had got another compressor and re-started production we ended up having to bring in 40,000 loaves from sister bakeries as far away as Birmingham to meet our Monday orders.
So that is the reason that I have always thought the RR Eagle engine to be a pile of rubbish and no one will convince me differently. If it couldn’t power a compressor what use was it in a truck?
Bewick:
Well said “GF” ! my sentiments exactly regarding those poxy RR220 's ! Cheers Dennis.
Aye they were crap, we only got between 10 and 18 years out of a 20+ fleet of them!
Pete.
So Pete why were they so unpopular with Hauliers ? The RR was never in the same class as the ■■■■■■■ or the Gardner–was it ? Cheers Dennis.PS Peter Foden would have done a “double back flip” and increased ERF production enormously if he could have persuaded many of his customers to order Chassis with the RR engine, he did try hard but to no avail !
Carryfast:
There are references out there to it having a penchant for piston breakages ? ( maybe as expected of a design based on the premise of trading leverage at the crank for more force at the piston ? ).That at around less than just 65 lb/ft per litre.Which leaves the question of what stopped the supposed after cooled 325 hp version in its tracks and what made Leyland drop the thing shortly after going to all the trouble of transferring production of it from AEC to Leyland ?.In favour of just using ■■■■■■■ and Rolls ?.Bearing in mind I don’t buy after cooling being too much to get their heads around in the day or cost.
So yes maybe just about good enough in service by the standards of the day but a disaster for Leyland’s in house engine manufacturing business model.In not having the necessary redundancy for development built in of the Rolls and ■■■■■■■■■■ the form of the required leverage at the crank.
Which leaves the question of the AEC V8.Which its own designers seem to have rightly disowned as being a lemon in them wanting it shelved ?.
So it doesnt fit with your theory, so tell us about piston breakages , not a well known fact and something i havent heard on here , so who were the hauliers that had trouble with the aforementioned breakdowns were they a regular occurence ■■?
You’ll find the references to piston issues in Colin Peck’s book British and European Trucks of the 1970’s in which BRS reputedly suffered piston failures on two TL12 Marathon demonstrators on test in under a year.So that was that customer out of the frame at least.
There’s also a reference out there of a TL12 with piston failure on route while on International work ? having the offending piston/rod assembly removed on the road and then driven home on 5 cylinders.While I believe the first bit of that story I don’t believe the second bit.
So I answered your question concerning the thing being more or less good enough by the standards of 1973 but an obsolete liability by 1978.How doesn’t that fit my ‘theory’ ?.While you don’t seem to have answered mine.
Bewick:
Well said “GF” ! my sentiments exactly regarding those poxy RR220 's ! Cheers Dennis.
Aye they were crap, we only got between 10 and 18 years out of a 20+ fleet of them!
Pete.
So Pete why were they so unpopular with Hauliers ? The RR was never in the same class as the ■■■■■■■ or the Gardner–was it ? Cheers Dennis.PS Peter Foden would have done a “double back flip” and increased ERF production enormously if he could have persuaded many of his customers to order Chassis with the RR engine, he did try hard but to no avail !
Search me Dennis! Ours were 265’s and 265Li’s but still basically the same engine and they lasted far longer between overhauls than any of our Gardners ever did.
windrush:
Search me Dennis! Ours were 265’s and 265Li’s but still basically the same engine and they lasted far longer between overhauls than any of our Gardners ever did.
Pete.
We know it went on to produce a reliable almost 110 lb/ft per litre in the form of the 375 TX which is a lot more than any Gardner or AEC motor ever made.Not to mention more than 7 mpg at 38t.
While it takes something bleedin bad for its own designers to tell their own employers not to use it.
Carryfast:
There are references out there to it having a penchant for piston breakages ? ( maybe as expected of a design based on the premise of trading leverage at the crank for more force at the piston ? ).That at around less than just 65 lb/ft per litre.Which leaves the question of what stopped the supposed after cooled 325 hp version in its tracks and what made Leyland drop the thing shortly after going to all the trouble of transferring production of it from AEC to Leyland ?.In favour of just using ■■■■■■■ and Rolls ?.Bearing in mind I don’t buy after cooling being too much to get their heads around in the day or cost.
So yes maybe just about good enough in service by the standards of the day but a disaster for Leyland’s in house engine manufacturing business model.In not having the necessary redundancy for development built in of the Rolls and ■■■■■■■■■■ the form of the required leverage at the crank.
Which leaves the question of the AEC V8.Which its own designers seem to have rightly disowned as being a lemon in them wanting it shelved ?.
So it doesnt fit with your theory, so tell us about piston breakages , not a well known fact and something i havent heard on here , so who were the hauliers that had trouble with the aforementioned breakdowns were they a regular occurence ■■?
You’ll find the references to piston issues in Colin Peck’s book British and European Trucks of the 1970’s in which BRS reputedly suffered piston failures on two TL12 Marathon demonstrators on test in under a year.So that was that customer out of the frame at least.
There’s also a reference out there of a TL12 with piston failure on route while on International work ? having the offending piston/rod assembly removed on the road and then driven home on 5 cylinders.While I believe the first bit of that story I don’t believe the second bit.
So I answered your question concerning the thing being more or less good enough by the standards of 1973 but an obsolete liability by 1978.How doesn’t that fit my ‘theory’ ?.While you don’t seem to have answered mine.
Especially in the case of the V8.
3 failures, two documented and one hearsay, hmmm, it’s a wonder they weren’t sent to the tower.
It’s also a bit contradictory as BRS ran hundreds of Leyland Buffalo with the ticking time bomb headless wonder, yet two TL12 failures wiped the Marathon off their wish list. To me that sounds like complete and utter rubbish (other words are available)
The V8 is another matter altogether, it’s well documented that the concept had not be a success and was put back in the filing cabinet, then under orders from the new bosses at BL, it was forced into production, the rest is history.
As for the RR Eagle, I never had much to do with them, had a 265 in a SedAk for a week, a 300LI in a Constructer 8wherler for a couple of months and I took a 325TX Leyland Roadtrain to Italy once, nothing good or bad to say as my experience was so limited, but I don’t really recall them being very popular apart from the in house tanker firms and obviously in the Crusader, which itself was a low volume lorry.
Carryfast:
Because it proves that hp isn’t dependent on piston area just like the Rolls Eagle did v the TL12 40 years ago.In all cases BMEP ( specific torque ) being the usually accepted figure.Which is why DAF obviously chose to stay with the bore size of the old DK engine when going from 11.6 to around 13 litre.That obviously being less than the TL12’s.Probably also why ■■■■■■■ reduced the bore diameter of the ISX from that of the N14 in the move up to 15 litre.
We are here again.The ISX bore was reduced to keep it in sub 16 litre territory but still keep the ultra long stroke(6.65).
The N14 didn’t have an ‘ultra long’ 6.65 stroke it retained the usual 855 6 inch one.
While if piston area is supposedly the relevant calculation as inferred in the article,rather than leverage at the crank,in making power why would ■■■■■■■ have wanted to reduce the bore and increase the stroke compared to the that of the N14 in the move from 14 litre to 15 ?.When BMEP ( specific torque ) is obviously all about the amount of force applied to a ‘given’ piston area x leverage at the crank.
ISX is 6.65 stroke,open your eyes,read,think,engage.
Carryfast:
There are references out there to it having a penchant for piston breakages ? ( maybe as expected of a design based on the premise of trading leverage at the crank for more force at the piston ? ).That at around less than just 65 lb/ft per litre.Which leaves the question of what stopped the supposed after cooled 325 hp version in its tracks and what made Leyland drop the thing shortly after going to all the trouble of transferring production of it from AEC to Leyland ?.In favour of just using ■■■■■■■ and Rolls ?.Bearing in mind I don’t buy after cooling being too much to get their heads around in the day or cost.
So yes maybe just about good enough in service by the standards of the day but a disaster for Leyland’s in house engine manufacturing business model.In not having the necessary redundancy for development built in of the Rolls and ■■■■■■■■■■ the form of the required leverage at the crank.
Which leaves the question of the AEC V8.Which its own designers seem to have rightly disowned as being a lemon in them wanting it shelved ?.
So it doesnt fit with your theory, so tell us about piston breakages , not a well known fact and something i havent heard on here , so who were the hauliers that had trouble with the aforementioned breakdowns were they a regular occurence ■■?
You’ll find the references to piston issues in Colin Peck’s book British and European Trucks of the 1970’s in which BRS reputedly suffered piston failures on two TL12 Marathon demonstrators on test in under a year.So that was that customer out of the frame at least.
There’s also a reference out there of a TL12 with piston failure on route while on International work ? having the offending piston/rod assembly removed on the road and then driven home on 5 cylinders.While I believe the first bit of that story I don’t believe the second bit.
So I answered your question concerning the thing being more or less good enough by the standards of 1973 but an obsolete liability by 1978.How doesn’t that fit my ‘theory’ ?.While you don’t seem to have answered mine.
Especially in the case of the V8.
Firstly the AEC engineers didnt want to put the V8 into production so early because it wasnt fully developed ,it was your old mentor Donald Stokes and his management team who forced the issue, the subject being covered by a contributor much more qualified than me who had actually spoken to
people who worked at AEC at the time.
You mention 2 piston failures at BRS not bad in a decade of production , you also mention a tale about a TL12 coming back from abroad on 5 cylinders , a tall tale in itself but you fail to mention the rest of the article where the author praises the Marathon ,very dubious.
The TL12 became obsolete in `78 why ■■? still reliable fast and economical ,the average haulier would be still buying 180/240 Gardners , 250 ■■■■■■■ , 265 RR , F86/F7 Scania 80s Merc 1625S Daf 2500s , then there was the 2800s F10s 111s E290s all similar bhp to the TL12 , the F10 by this time downrated to 278 bhp from a 9.6 litre engine that would eventually push out 320 bhp
Bewick:
Well said “GF” ! my sentiments exactly regarding those poxy RR220 's ! Cheers Dennis.
And what did the replacement compressor have in it? A ■■■■■■■ 250 that purred away non-stop for 3 days and nights and never missed a beat.
Well of course ! no contest there ! Cheers Dennis.
Have to admit that our two 250 ■■■■■■■ engined Fodens did manage around four years before requiring work so about the same time span as the Patricroft product. They were sold on after six years anyway and no more came, it was Rolls all the way then until Tilcon sold the fleet off. No AEC V8’s were bought either!
Carryfast:
While if piston area is supposedly the relevant calculation as inferred in the article,rather than leverage at the crank,in making power why would ■■■■■■■ have wanted to reduce the bore and increase the stroke compared to the that of the N14 in the move from 14 litre to 15 ?.When BMEP ( specific torque ) is obviously all about the amount of force applied to a ‘given’ piston area x leverage at the crank.
ISX is 6.65 stroke,open your eyes,read,think,engage.
That’s exactly what I said.The ISX has a smaller bore and a longer stroke than the N14.
So how does ‘reducing’ the bore size and ‘increasing’ the stroke ‘from’ that of ‘the N14’ to ‘increase’ capacity from 14 to 15 litre,fit AEC designers’ inference that power output is supposedly dependent on piston area ?.As opposed to prioritising leverage at the crank ?.
ramone:
Firstly the AEC engineers didnt want to put the V8 into production so early because it wasnt fully developed ,it was your old mentor Donald Stokes and his management team who forced the issue, the subject being covered by a contributor much more qualified than me who had actually spoken to
people who worked at AEC at the time.
You mention 2 piston failures at BRS not bad in a decade of production , you also mention a tale about a TL12 coming back from abroad on 5 cylinders , a tall tale in itself but you fail to mention the rest of the article where the author praises the Marathon ,very dubious.
The TL12 became obsolete in `78 why ■■? still reliable fast and economical ,the average haulier would be still buying 180/240 Gardners , 250 ■■■■■■■ , 265 RR , F86/F7 Scania 80s Merc 1625S Daf 2500s , then there was the 2800s F10s 111s E290s all similar bhp to the TL12 , the F10 by this time downrated to 278 bhp from a 9.6 litre engine that would eventually push out 320 bhp
What was the miracle cure that AEC were going to be able to apply to an engine,that was obviously based on the wrong design premise,applying to an F1 race engine,from the start.
The fact that the TL12 was up against things like the E290,let alone E320 is the point.If you really want to believe that the TL12 was any match for that or even the Rolls Eagle great that’s your view and I won’t change it.
windrush:
Have to admit that our two 250 ■■■■■■■ engined Fodens did manage around four years before requiring work so about the same time span as the Patricroft product. They were sold on after six years anyway and no more came, it was Rolls all the way then until Tilcon sold the fleet off. No AEC V8’s were bought either!
Pete.
Bewick wasn’t exactly known for his fleet of AEC V8 powered Ergos either for some reason.
While to be fair the TL12 probably would have been fine in 6 and 8 wheeler rigids well into the 1980’s.So what did Leyland do they put the fixed head wonder in them instead.
Which leaves the question why was the 680 the motor of choice in the Scammell Routeman 8 wheeler and not the TL12 which would seem to be its natural home if anywhere ?.
Carryfast:
So how does ‘reducing’ the bore size and ‘increasing’ the stroke ‘from’ that of ‘the N14’ to ‘increase’ capacity from 14 to 15 litre,fit AEC designers’ inference that power output is supposedly dependent on piston area ?.As opposed to prioritising leverage at the crank ?.
We’ve been down this route before. The conclusion was that, in the 1960s and '70s, there were V engines of all dimensions. Most entered production with minor faults- even the revered Swedish V8 was not without the odd teething trouble. Berliet’s solution to the unreliability of their V8 included an increase in the bore. Two of the engines with (to my knowledge) unblemished reputations were oversquare- Unic and Fiat.
Change the record, please. You’re talking bolleaux, even by your own high standards.
I’m sorry to say as a new member I’m starting to find this frustrating.You(CF) have no idea over the design problems engine manufactures face.When AEC were producing engines they were no worse than any other manufacture,■■■■■■■ have had plenty of problems over the years I don’t mind admitting,Volvos 290 hp TD100 was a complete wash out,Scanias vee eight had issues cracking blocks across the main housings,MANs D25/D28 had a variety of issues,the Rolls Eagle had liner protrusion problems cured in the end with the back bone gasket.The TL12 was one of the most reliable probably due to leaving the HP low(er).What I know of the 800 series could have easy been cured,the premature failure of the mains was put down to not enough surface area and the oiling hole in the wrong place,the overheating was mainly due to the fan having a direct drive off the crank pulley,again lifting the cab could have ment relocation of fan and geared up the fan speed.Another problem seemed to be injectors sticking open,did the fuel pump not include delivery valves.All easy stuff to remedy.
