gingerfold:
^^^^^^^^^
You must never have travelled on a Lancashire United Transport Guy with a Gardner engine. They were very noisy.
Plenty of LX and LXB’s went into buses though. I don’t recall it having a reputation for noise, although I recall, from reading this forum, that the early Eagle was a noisy engine.
The “loose engine” bus market was substantial for many years. Bristol, Daimler, and Guy had no in-house engine production facility (Daimler did dip it’s toe in the water for a short time). A quick tally of Gardner engines supplied to those three assemblers between 1937 and 1975 were
Bristol, 15,000, Daimler 13,500, and Guy 16,000 - combined total for lorries and PSVs, but including 38 8LXB 240’s Those totals should have been of interest to RR, and back in the day there was a certain amount of prestige in supplying the bigger municipal and city fleets. Leyland never forgave AEC for being the supplier of 75% of London Transport’s needs for decades.
gingerfold:
^^^^^^^^^
You must never have travelled on a Lancashire United Transport Guy with a Gardner engine. They were very noisy.
Plenty of LX and LXB’s went into buses though. I don’t recall it having a reputation for noise, although I recall, from reading this forum, that the early Eagle was a noisy engine.
Ironically the sound of the Matador’s motor or a 590/690 in a bus was up there with the Merlin and the BMC C series as iconic not objectionable.
Not sure how an early Eagle could possibly have been much different to a later one.I preferred the 265 to the NA ■■■■■■■ in the Atki at least.
The fact is 12 litre + motors were never going to be high on the PSV buyers’ list at that point.
On that note was the TD120 used much if at all in Volvo PSV’s ?.
Well obviously all those AEC Reliance operators in the 70s must have bought the wrong coaches
So going forward from the late 60s which engines should the BL conglomerate have kept in production sufficient long enough to alow time for full testing of engines in the pipeline (and abort them if unsuitable) and also develop a completely new range of engines for the mid 70s on?
Carryfast:
I don’t get your link between the V8 and the 760 at their respective design stages and Leyland.
The erroneous design philosophy is contained within the reference to the ■■■■■■■ court case.
Something made AEC’s designers jump from the 0.71 bore stroke ratio of the 7.5 litre Matador motor and 0.84 of the 590 to the 0.95 and 1.18 of the 760 and V8 respectively.
Leyland obviously had no input into that decision.AEC’s designers were obviously fixated on the idea of the big bore and short stroke philosophy.Why else would the ■■■■■■■ court case even have mattered to them.When they already had the examples of the O853 and the 590 to go by.
Going by the 590 that would have given them a 12.2 litre 130 x 154 design.Perfect a Rolls and TD120 and probably 14 litre ■■■■■■■ killer.
The 590 and 690 stay to power the continuing production of Routemasters.
You can’t blame Leyland for that.
You can at worst blame bad design.
Or at best weak designers not willing to take on their managers in a blazing row and get it on record, and/or the bankers deliberately with holding resources from Stokes after that.
I’m sure that any designer worth their salt saying that our truck engines have to be as good as our bus engines and the 760 based TL12 won’t cut it would have been met by approval from Stokes.
The government and bankers were obviously working to a more treacherous agenda though regardless.
Ironically the smoking gun is contained in the Hansard regarding closure of Park Royal.The bs regarding the move to OMO on London buses doesn’t add up when the Routemaster was more in demand and loved than ever by its users and crews during the late 1970’s.
Quite simply there was no link between the V8 and the AV760 , i said if AEC were to have kept their profits and reinvested them into development then they would have probably designed a new engine by the mid 70s . As for the V8 it was a project they never wanted to put into production but were forced to by Leyland bosses. But again the TL12 did cut it right up to its demise in the very early 80s when Leyland decided to do the total opposite to every European manufacturer that has survived and buy in engines because there were no funds to build a new engine . The basis for the AECs engines were never a bad design
The basis of moving from a bore stroke ratio of 0.84 in the case of the 590 to 0.95 was ‘bad design’.
That’s why Leyland ‘needed’ a new engine less than 10 years after the introduction of TL12.
Whereas 130 x 154 would have easily seen Leyland well into the 1990’s.
There was a link between that and the V8 in terms of that design thinking taken to the even worse extreme in the case of the V8.
If the V8 was a project never intended for production why didn’t its designers stop it at the design stage and destroy their drawings in 1962.Instead of obviously passing them through the door.What was the ■■■■■■■ court case issue supposedly all about it would be totally irrelevant.
So Stokes says put it into production they say put what into production it only existed in our thinking but we abandoned it because an over square motor isn’t what we needed/need.It’s history.
But ironically a V8 powered VTG would work based on the 690’s 130 x 142 architecture to add to a new 130 x 154 6 cylinder development, or we walk away from the job.What’s he gonna do.
The truth is like the 760 the V8 was designed in the early 1960’s under Markland not Stokes.
It’s designers knew it was a lemon but obviously not at the design stage.They really did think that a 114 mm stroke max weight truck engine would work.Rather than admit their mistake or even acknowledge any mistake they said its issues could be fixed they didn’t say destroy the drawings and any tooling.Stokes then blundered into the resulting minefield long after that point. aronline.co.uk/facts-and-fig … v8-diesel/
gingerfold:
The “loose engine” bus market was substantial for many years. Bristol, Daimler, and Guy had no in-house engine production facility (Daimler did dip it’s toe in the water for a short time). A quick tally of Gardner engines supplied to those three assemblers between 1937 and 1975 were
Bristol, 15,000, Daimler 13,500, and Guy 16,000 - combined total for lorries and PSVs, but including 38 8LXB 240’s Those totals should have been of interest to RR, and back in the day there was a certain amount of prestige in supplying the bigger municipal and city fleets. Leyland never forgave AEC for being the supplier of 75% of London Transport’s needs for decades.
It’s obvious by those figures that there was effectively no market for >12 litre bus engines.
AEC also didn’t use the 760 for buses so why would use of the Eagle be any different ?.
Even the 690 was only used in the Green Line Routemaster ‘specials’.Arguably the best bus ever made here.
essexpete:
So going forward from the late 60s which engines should the BL conglomerate have kept in production sufficient long enough to alow time for full testing of engines in the pipeline (and abort them if unsuitable) and also develop a completely new range of engines for the mid 70s on?
Realistically the AEC V8 or the 760/L12/TL12 shouldn’t have even got off the drawing board let alone to testing.
There’s a glaring unanswered question as to how and why did AEC abandon the type of accepted bore stroke ratio contained in the 590.That obviously occurred before Stokes’ reign and without any input from Leyland’s designers.They were AEC designs designed by AEC’s staff.
It’s obvious that the 690 was just a 590 development more suited to bus use.
No way was there ever a design, let alone production, case for the 760, let alone the V8, for use in max weight trucks.
gingerfold:
Leyland never forgave AEC for being the supplier of 75% of London Transport’s needs for decades.
Yet I’m guessing it was Stokes who cleared the 690 to be put in the Green Line Routemaster ?.
It was Edwardes who closed both Park Royal and Southall.
The information suggests that Stokes also wasn’t the main player in the decision to end production of the Routemaster ?.That seems to have been more the LT board among others ?.
The same LT board that were instrumental if the formation of the AEC ?.
Carryfast:
The fact is 12 litre + motors were never going to be high on the PSV buyers’ list at that point.
On that note was the TD120 used much if at all in Volvo PSV’s ?.
Well obviously all those AEC Reliance operators in the 70s must have bought the wrong coaches
I did say ‘not high on the list’ so exceptions proving rules like the 38 Gardner 240’s.
Also don’t know of any Horizontal Eagles ?.
essexpete:
So going forward from the late 60s which engines should the BL conglomerate have kept in production sufficient long enough to alow time for full testing of engines in the pipeline (and abort them if unsuitable) and also develop a completely new range of engines for the mid 70s on?
Realistically the AEC V8 or the 760/L12/TL12 shouldn’t have even got off the drawing board let alone to testing.
There’s a glaring unanswered question as to how and why did AEC abandon the type of accepted bore stroke ratio contained in the 590.That obviously occurred before Stokes’ reign and without any input from Leyland’s designers.They were AEC designs designed by AEC’s staff.
It’s obvious that the 690 was just a 590 development more suited to bus use.
No way was there ever a design, let alone production, case for the 760, let alone the V8, for use in max weight trucks.
Realistically you never come out with a realistic statement. The 760 TL12 should never have been built is one of your biggest load of crap to have been posted
Rolls Royce Eagle engines were fitted to some Dennis Dominator chassis notably for South Yorkshire PTE who took ‘significant numbers’. London also trial fitted and then operated a small batch of Eagle powered Daimler Fleetlines (DM & DMS class).
The 690 and 691 engines were fitted ss an option to the Regent V double deck chassis which several operators took up along with a few who opted for the Gardner 6LW. The last Regent V built had a 691.
The 690, 691 and 760 were all sold in significant numbers fitted to Reliance chassis.
Edit add:
We have been over the end of AEC Routemaster production ad nauseam, the vehicle is possibly more accurately described as a Park Royal bus fitted with AEC mechanical units, but to repeat:
The contunued production of RM type buses by AEC would have seen the company’s demise much more quickly.
I can’t be bothered to look up the exact numbers yet again but fewer than 100-150 buses were sold to operators other than London Transport. This was for a very simple reason - no one else wanted them; they were viewed as outdated with an open rear platform and too expensive and had been viewed from day one as having features which were viewed with suspicion by their fleet engineers.
The only other customer for the bus now also no longer wished to purchase any more of the type, because dwindling bus useage and revenue meant they could not afford the pay rates to attract the staff to operate vehicles which required a crew of two. This left AEC with the option of ending production or filling their yard with vehicles they could not sell and therfore would be unable to recoup their production costs.
You cannot sell what people don’t want.
The fact that there was a prototype front entrance RM running in service is just really like the TL12’s future development: just another might have been. The truth surrounding this is that BL already had three front entrance, rear engine, double deckers in production; they did not want a fourth challenger at a time when the object was to streamline model production.
essexpete:
So going forward from the late 60s which engines should the BL conglomerate have kept in production sufficient long enough to alow time for full testing of engines in the pipeline (and abort them if unsuitable) and also develop a completely new range of engines for the mid 70s on?
Realistically the AEC V8 or the 760/L12/TL12 shouldn’t have even got off the drawing board let alone to testing.
There’s a glaring unanswered question as to how and why did AEC abandon the type of accepted bore stroke ratio contained in the 590.That obviously occurred before Stokes’ reign and without any input from Leyland’s designers.They were AEC designs designed by AEC’s staff.
It’s obvious that the 690 was just a 590 development more suited to bus use.
No way was there ever a design, let alone production, case for the 760, let alone the V8, for use in max weight trucks.
What I am really asking which group engines should have been carried forward until combined efforts could produce a new engine for the mid 70s and on. That is assuming that the AEC V8 and the Leyland 500 were found problematical in more extensive testing and therefore aborted. All pointless hypothesis I know.
essexpete:
So going forward from the late 60s which engines should the BL conglomerate have kept in production sufficient long enough to alow time for full testing of engines in the pipeline (and abort them if unsuitable) and also develop a completely new range of engines for the mid 70s on?
Realistically the AEC V8 or the 760/L12/TL12 shouldn’t have even got off the drawing board let alone to testing.
There’s a glaring unanswered question as to how and why did AEC abandon the type of accepted bore stroke ratio contained in the 590.That obviously occurred before Stokes’ reign and without any input from Leyland’s designers.They were AEC designs designed by AEC’s staff.
It’s obvious that the 690 was just a 590 development more suited to bus use.
No way was there ever a design, let alone production, case for the 760, let alone the V8, for use in max weight trucks.
Realistically you never come out with a realistic statement. The 760 TL12 should never have been built is one of your biggest load of crap to have been posted
+1 to that last statement. New audience, same pretend engineering.
Do the calculation of bearing loads, like I told you, charlatan.
It must have been like this in 1970s unionised factories, when it was impossible to sack fools, so the whole job was compromised. I would be quite interested to see my own theories of why oversquare diesels eventually fell from favour, but no base engine design specialist is going to come here, with that^^^ going on.
Rolls Royce Eagle engines were fitted to some Dennis Dominator chassis notably for South Yorkshire PTE who took ‘significant numbers’. London also trial fitted and then operated a small batch of Eagle powered Daimler Fleetlines (DM & DMS class).
The 690 and 691 engines were fitted ss an option to the Regent V double deck chassis which several operators took up along with a few who opted for the Gardner 6LW. The last Regent V built had a 691.
The 690, 691 and 760 were all sold in significant numbers fitted to Reliance chassis.
Surely that just adds more weight to the question of bringing RR in house and maintaining AEC and Park Royal’s position.That would give AEC a monopoly over 690/691/760 and RR bus engine option production.That’s obviously a lot of ongoing engine sales.
Bearing in mind both were still in business as of 1975 when Stokes was exiled and the Edwardes era was about to start.
But surprised that the 760 or the Eagle were chosen in any numbers to power buses.
But the 690/1 created the ultimate Routemaster so can understand that choice in the Regal V.
What is certain is that, unlike the Eagle, the 760/TL12 was too close to the ideal bus engine to be an ideal 32 tonner engine.Basically it was just a bored out version of a motor which was made to fit and to work in a 7.5t Routemaster bus and even that originally with an 0.84 bore stroke ratio in the case of the 590.
essexpete:
What I am really asking which group engines should have been carried forward until combined efforts could produce a new engine for the mid 70s and on. That is assuming that the AEC V8 and the Leyland 500 were found problematical in more extensive testing and therefore aborted. All pointless hypothesis I know.
For the truck division at that point bringing RR on board was Leyland’s only realistic max weight truck option.AEC had blown it by obviously concentrating on their bus engine designs let alone the V8.
Scammell had already paved the way for that to happen.
There was no money and no point in designing something else to add to it.
It contained everything Leyland needed to take on both DAF and Volvo.Unlike the TL12.
Oh wait remind me who the truck and bus division were eventually handed over to.
I also described the similar case of the only realistic way forward for the car divisions.
Again what looks like a concerted plan of sabotage in place to benefit the foregone sell out to the foreign competition.
ramone:
Realistically you never come out with a realistic statement. The 760 TL12 should never have been built is one of your biggest load of crap to have been posted
+1 to that last statement. New audience, same pretend engineering.
Do the calculation of bearing loads, like I told you, charlatan.
It must have been like this in 1970s unionised factories, when it was impossible to sack fools, so the whole job was compromised. I would be quite interested to see my own theories of why oversquare diesels eventually fell from favour, but no base engine design specialist is going to come here, with that^^^ going on.
You mean like using your figure of 2 x BMEP being all you need to worry about that’s all it will take to get 100 lb/ft per litre and more than 270 hp from your 12.4 litre anchor.So what about head to block joint and fastening loads too.Bearing in mind your net leverage v piston area deficit that you’re also going to have to compensate for with higher cylinder pressures added to the greater force applied to the con rod assembly.
The whole job compromised by unions.You mean the ones waiting for the designers to give them something better to make than a bored out bus motor.Let alone a short stroke V8 only fit for scrap before it was ever fitted in a truck.
Oh wait I thought it was all Stokes’ fault and I’ve never professed to being an ‘engineer’ I was a driver.Unlike the designers of the 760 and V8.
Carryfast:
The fact is 12 litre + motors were never going to be high on the PSV buyers’ list at that point.
On that note was the TD120 used much if at all in Volvo PSV’s ?.
Well obviously all those AEC Reliance operators in the 70s must have bought the wrong coaches
I did say ‘not high on the list’ so exceptions proving rules like the 38 Gardner 240’s.
Also don’t know of any Horizontal Eagles ?.
The RR Eagle engine was used in DMU railcars, presumably in horizontal configuration■■?.
The AEC 7.7 litre unit (7.65 l actually) as used in the Matador was a 146 mm stroke design. I was told the reason once why AEC shortened the stroke of subsequent engines to 142 mm, but for the life of me I cannot remember what the reason was…
essexpete:
So going forward from the late 60s which engines should the BL conglomerate have kept in production sufficient long enough to alow time for full testing of engines in the pipeline (and abort them if unsuitable) and also develop a completely new range of engines for the mid 70s on?
Realistically the AEC V8 or the 760/L12/TL12 shouldn’t have even got off the drawing board let alone to testing.
There’s a glaring unanswered question as to how and why did AEC abandon the type of accepted bore stroke ratio contained in the 590.That obviously occurred before Stokes’ reign and without any input from Leyland’s designers.They were AEC designs designed by AEC’s staff.
It’s obvious that the 690 was just a 590 development more suited to bus use.
No way was there ever a design, let alone production, case for the 760, let alone the V8, for use in max weight trucks.
What I am really asking which group engines should have been carried forward until combined efforts could produce a new engine for the mid 70s and on. That is assuming that the AEC V8 and the Leyland 500 were found problematical in more extensive testing and therefore aborted. All pointless hypothesis I know.
Using Pat Kennett as a source then it’s generally accepted that the main-stream Leyland engines for the various weight categories had reached the end of their development lives. The Leyland O.680 had its origins dating back to 1943, although it was successful as a lightly turbo-charged unit, the TL11. Similarly, the O.400 had evolved through the O.300, O.350, O.375 and the O.300 was actually based on a WW2 multi-fuel Napier design.
The main-stream AEC engines were much newer, with the last much re-vamped types being introduced in 1965. As we have seen Leyland decreed that the AV760 could be developed into the TL12 and a superb engine it was in service. A similar exercise could have been carried out with the AV505, and development work was started on a turbo-charged version, and the AV506 was a normally aspirated version of a turbo-charged unit that never was. The AV506, like the L12, didn’t breathe very well, and it wasn’t as lively as an AV505.
gingerfold:
…The AV506, like the L12, didn’t breathe very well, and it wasn’t as lively as an AV505.
Somewhere in these threads, if I remember correctly, is the reason for the L12 not breathing as well as the AV760. What are the details contributing to that, please?
(Apologies for not spending the hours necessary to find that morsel of sense, among the reams of piffle).
gingerfold:
…The AV506, like the L12, didn’t breathe very well, and it wasn’t as lively as an AV505.
Somewhere in these threads, if I remember correctly, is the reason for the L12 not breathing as well as the AV760. What are the details contributing to that, please?
(Apologies for not spending the hours necessary to find that morsel of sense, among the reams of piffle).
Was it because the L12 was derived from a turbocharged engine , i think newmercman explained in detail why
