newmercman:
I’ve run big power lorries in my time, every one of them liked a drop of fuel, I bought them because I could, there were no sound business reasons, they were pure indulgence on my part.
I had a 430 Stralis running alongside my 540s, on all but the biggest hills you never knew the difference, until you got to the fuel pumps, the 430 had a meagre thirst compared to it’s bigger siblings. That was running at 44tonnes both ways from London to South Wales and back every night and local work in and around the M25 during the day, sort of throws CF’s argument out the window I reckon, especially as it’s real world, not theory or a youtube video!
My argument is sound because it’s based on the ‘real world’ of premium long haul truck development history over the years the clue being that the industry ( at least in the case of Leyland truck group ) progressed forwards from products like the 500 powered ERGO to products like the 300 hp + Rolls and ■■■■■■■ powered T45 just as Volvo started with products like the F88 and moved on with products like the F12.Not vice versa.
If I’m wrong the course of progress would have been the exact opposite of that.As I’ve said in general around 10 hp per tonne gross weight has been proven to be a minimum requirement to get the otptimum combination of fuel efficiency and productivety while in general it takes an engine of not less than 11 litres to provide the required combination of specific and overall torque output ( which is what it’s all about ) and reliablity by keeping stress levels within tolerable limits.If you want to go on with believing a different version of history ( probably based on unrepresentative comparisons of using more of the power of a big power truck than just the increased torque ) that’s your choice.
Although having said that there’s nothing within your comments there which would suggest that a minimum of around 10 hp per tonne,just as I’ve said,isn’t more efficient than running a truck with a lot less of a power to weight ratio.As in all cases,of running a truck with a higher power to weight ratio than that,it’s obvious that you’ll use more fuel if you use all of the extra power,rather than running at the same average speed but using less engine speed to do it.
Yes in the last 10 or 15 years that has become the accepted norm around 10bhp a ton. But lets not forget otger than the odd supertruck of the era like the v8 scania f89 volvo the majoraty of european trucks were rather more modestly powered.
kr79:
Yes in the last 10 or 15 years that has become the accepted norm around 10bhp a ton. But lets not forget otger than the odd supertruck of the era like the v8 scania f89 volvo the majoraty of european trucks were rather more modestly powered.
Well unless you count the very rare 335 ■■■■■■■ engined Marathon there werent any Ergos with 10 bhp per ton or more .Not that there were many other manufactureres offering that sort of power in their bread and butter motors at the time either.It wasnt until the 38 ton limit was introduced that the 300bhp level was surpassed and then it was mainly 320 - 360 that most operators found adequate in the later `80s.Like newmercman said owner drivers or those who could overindulge went for the higher horsepower motors
kr79:
Yes in the last 10 or 15 years that has become the accepted norm around 10bhp a ton. But lets not forget otger than the odd supertruck of the era like the v8 scania f89 volvo the majoraty of european trucks were rather more modestly powered.
Well unless you count the very rare 335 ■■■■■■■ engined Marathon there werent any Ergos with 10 bhp per ton or more .Not that there were many other manufactureres offering that sort of power in their bread and butter motors at the time either.It wasnt until the 38 ton limit was introduced that the 300bhp level was surpassed and then it was mainly 320 - 360 that most operators found adequate in the later `80s.Like newmercman said owner drivers or those who could overindulge went for the higher horsepower motors
No one is arguing about the situation concerning the fact that the majority of British operators were using underpowered wagons up to around the end of the 1970’s based on their outdated thinking.‘But’ the relevant thing in this case is that the designers knew long before those customers eventually changed their minds what was going to be needed.As for the idea of it being ‘the accepted norm’ for most operators to still not be calling for around 10 hp per tonne until at least 20 or even 10 years after that time is totally unrealistic.However the Rolls powered Crusader was a lot further down the road towards the eventual Rolls and ■■■■■■■ powered 300 + hp T45 market sector than the 500 powered ERGO or the TL12 powered Marathon were.Just as a Rolls,■■■■■■■■■■ 700 fixed head powered AEC 3VTG development might have been.
The fact is both Scammell and AEC obviously had the engineering ability and know how to make a more reasonable competitor to the F10/F12 for example,before Volvo did it,than the blind alley and wasted development of the ERGO and the Marathon ever did.
Geoffrey, you jump from the F88 to the F12, forgetting all about the bread and butter F10, another thing you are probably unaware of is that the 290 F88 produced over 300hp when the he fan was disengaged and that the load lugger F12 (the econony version) produced a mere 305hp, on the road a 290 would leave a load lugger for dead and if driven properly the mpg would be very similar.
The Td120g was the start of Volvo’s high torque, low rpm designs, up until then they had relied on high rpms & a lot of gears to keep their engines singing.
This is a philisophy that BL had already adopted with the low revving TL12!
It’s quite surprising what comes to light unexpectedly from time to time. I’ve just received a copy of the AEC Society’s latest newsletter and it contains a short article lifted from an archive of “Commercial Motor” from the early 1960s. It illustrates the investigation into additional engine power that was being trialled by AEC’s engineers. They fitted a turbo-charger onto an AEC 11.3 litre engine in a Bowaters Mammoth Major Eight wheeler. (The MM8 was actually a Mk.2 version, in production mid-1930s to 1940, then 1945-46, so a venerable old lady of a truck in the early 1960s and obviously re-engined with a later 11.3 litre unit). Whilst no specific power outputs are quoted (the 11.3 could produce up to 165 bhp in normally aspirated road-going applications) the performance of this eight-wheeler was transformed, especially on hills where it was climbing them one gear higher when compared with its stable-mates, and it was running at higher weights than the normal 22 / 24 tons gvw applicable at the time. (A MM Mk.2 was originally 22 tons gvw). BUT, fuel consumption was worse and the cab got hotter!!. What did surprise me was that Bowaters’ fleet average for its Mammoth Major 8s (and they had plenty of them) was 9.3 mpg, probably the majority of the runs were one-way loaded. Typical work for them was newsprint from the Medway paper mills into Fleet Street, London. AEC had been fitting turbochargers onto some engines since the 1950s, but usually for industrial, railcar, and special application engines including those working at high altitudes in trucks destined for South America.
Interesting Graham. 9.3mpg is a pretty decent return, when you take into account the low ULW of those MM8s, their purchase price and their low maintenance costs, due to not having much that could go wrong, I bet there’s not much on the road today that could match them for productivity. Progress eh!
newmercman:
Interesting Graham. 9.3mpg is a pretty decent return, when you take into account the low ULW of those MM8s, their purchase price and their low maintenance costs, due to not having much that could go wrong, I bet there’s not much on the road today that could match them for productivity. Progress eh!
My sentiments exactly. 15 years was the planned life of a truck in fleets such as Bowaters then, with probably a complete overhaul at about 8 years old. I have trouble finding drivers willing to drive a truck at 3 years old, let alone at 15 years old. Progress eh Some progress in many areas to do with trucks and their operation, but also plenty of regression in other areas.
Poor carryfast doesnt seem to comrehend that for every scania 141 sold there were probaly 20 111s on the road. Thats not just retarded british hauliers thats across europe.
The same as now can anyone running at 44 tons prove they get a noticable amount of more work done in say a scania r730 compared to an r480.
Or is it a case they run it because they can.
newmercman:
Geoffrey, you jump from the F88 to the F12, forgetting all about the bread and butter F10, another thing you are probably unaware of is that the 290 F88 produced over 300hp when the he fan was disengaged and that the load lugger F12 (the econony version) produced a mere 305hp, on the road a 290 would leave a load lugger for dead and if driven properly the mpg would be very similar.
The Td120g was the start of Volvo’s high torque, low rpm designs, up until then they had relied on high rpms & a lot of gears to keep their engines singing.
This is a philisophy that BL had already adopted with the low revving TL12!
As I’ve said the know how and engineering ability was there within the Leyland Group ( obviously more with Scammell and AEC in view of the choice of going for the idea of the 500 engine and the ERGO and Marathon cab for premium top weight trucks which seems to have been a Leyland thing ) to introduce the low engine speed high torque idea before Volvo did it.However the important thing is that it’s no surprise,as always,that an engine of at least 11 litres,preferably more,was needed for that job.
As for the so called ‘flexitorque’ ‘low revving’ TL12 it was really just a re rated version of the Marathon lump while trying to optimise the relatively low output it actually had.When it’s obvious that it was the 305 Rolls used in the Crusader since at least the mid 1970’s which was the better engine all round.IE the TL12 needed around 1,800 rpm to make 250 hp while the 305 was only running at less than 1,600 to make the same output with a specific fuel consumption of 210 g/kwhr as opposed to over 220 for the TL12 at that output and things just got a lot worse in the case of the TL12 as the power output increased towards it’s maximum running out of steam at well under 300 hp with an engine speed of well over 2,000 rpm and it’s sfc going off the chart at around 230. Whereas the Rolls was putting out around 300 hp at 2,000 rpm with sfc still under 230 at that output. ‘However’ at that point in time ( 1980 ) we’re talking about Rolls development moving forwards from the old 1970’s 305 up to it’s 350 version which is what ‘eventually’ found it’s way into the T45 while the idea of using the TL12 was rightly forgotten about by any customer with any sense.
However as we’ve seen you would have been making the case for continuing on with that lame old AEC lump because you didn’t want to look to the customers like a kit car builder using outside engine supplies.
kr79:
Poor carryfast doesnt seem to comrehend that for every scania 141 sold there were probaly 20 111s on the road. Thats not just retarded british hauliers thats across europe.
The issue of the customer choice and/or the advantages,between going for a 6 cylinder powered truck v an 8 cylinder one,is a totally different issue to that of the time line,over which the idea,of high torque otputs ( of which a high top end peak power output is just an essential by product ) became the accepted engineering solution to producing the otpimum combination of productivety,in the form of high average speeds,with fuel efficiency.The main ingredient of that solution being all about producing as much power as possible at as low engine speeds as possible and that solution exists to this day in all types of diesel engine technology from ships to cars regardless of engine type or number of cylinders.
Yes the British truck operators were guilty as charged in being retarded in their thinking in lagging way behind the engineers who knew that a lot sooner than their customers did.
Contrary to your and nmm’s ideas,concerning truck development timelines,this is a more accurate view of how things stood and were moving forward,at least amongst the engineers,in 1980 with products ready for the market which obviously would have been at the design stage ( a lot ) earlier than that.
Although it’s not surprising that maybe both you and nmm might not be fully aware of the rate of development at the time being,that if I’ve read it right,nmm would still have been in the secondary school system and you would have been around infants school age at the time .Rather than,as in my case,having already having spent 5 years before then working at shop floor level and then as a works driver for a large truck manufacturer .
But the fact remains all over europe the 110 111 scania and the f88 and f10 sold in much larger numbers and were about on par with what british trucks were power wise.
The 111 only went up to 305bhp when by that time the 290 ■■■■■■■ was pretty popular in british trucks.
That was seen as adequite to do the job then.
The only two markets that bucked tge trend were italy and to an extend ireland. But thst was largely to do with there operating conditions.
And the days of paddy one hitting it at 75 mph to italy and back while nailed to the floor both ways is a thing of tbe past other than in limeyphils head
kr79:
But the fact remains all over europe the 110 111 scania and the f88 and f10 sold in much larger numbers and were about on par with what british trucks were power wise.
The 111 only went up to 305bhp when by that time the 290 ■■■■■■■ was pretty popular in british trucks.
That was seen as adequite to do the job then.
The only two markets that bucked tge trend were italy and to an extend ireland. But thst was largely to do with there operating conditions.
And the days of paddy one hitting it at 75 mph to italy and back while nailed to the floor both ways is a thing of tbe past other than in limeyphils head
I think the big difference between the swedes and the british offerings were the cabs and build quality.We never really got to grips with building a decent cab with quality fittings ,the mercs before 89 were nothing spectacular interior wise but they were well put together ,the Brits tended to use cheaper plastics the insulation was never good and they had an overall feeling of being made on the cheap,just my opinion.It needed investment , some headhunting and a total rethink .Im still trying to work out how the Rolls Royce could be tuned to 350bhp but the TL12 couldn`t in CFs opinion.The reason Leyland stopped developing the TL12 was purely financial, it was cheaper to let ■■■■■■■ and Rolls do the hard work.Neither supply engines to top weight tractors sold here now.
kr79:
But the fact remains all over europe the 110 111 scania and the f88 and f10 sold in much larger numbers and were about on par with what british trucks were power wise.
The 111 only went up to 305bhp when by that time the 290 ■■■■■■■ was pretty popular in british trucks.
That was seen as adequite to do the job then.
The only two markets that bucked tge trend were italy and to an extend ireland. But thst was largely to do with there operating conditions.
And the days of paddy one hitting it at 75 mph to italy and back while nailed to the floor both ways is a thing of tbe past other than in limeyphils head
Exactly even much later driveline wise an erf or foden with a 14 litre ■■■■■■■ and fuller box was more than a match for a scania 143 or volvo f16 but the cabs always had that kit car feel.
Ironicaly the much hated by carryfast t45 cab was pretty good especaly the interstate.
kr79:
Exactly even much later driveline wise an erf or foden with a 14 litre ■■■■■■■ and fuller box was more than a match for a scania 143 or volvo f16 but the cabs always had that kit car feel.
Ironicaly the much hated by carryfast t45 cab was pretty good especaly the interstate.
And it was very similar to a Merc cab from the outside
kr79:
But the fact remains all over europe the 110 111 scania and the f88 and f10 sold in much larger numbers and were about on par with what british trucks were power wise.
The 111 only went up to 305bhp when by that time the 290 ■■■■■■■ was pretty popular in british trucks.
That was seen as adequite to do the job then.
The only two markets that bucked tge trend were italy and to an extend ireland. But thst was largely to do with there operating conditions.
And the days of paddy one hitting it at 75 mph to italy and back while nailed to the floor both ways is a thing of tbe past other than in limeyphils head
I think you’re still looking at it all from the wrong angle of concentrating on peak power outputs being used to their max to make average speeds as fast as possible.When the actual aim was all about the amount of power well below peak power ( torque ) which could be obtained in which case it’s nothing to do with a comparison of just peak power outputs.Which is why you’re right high powered trucks being driven close to peak power is a thing of the past because it’s not fuel efficient and it’s outside of the design aims of big power engines as intended by their manufactuers.What we’re now left with is more or less such power outputs being used as intended in it being the torque which is what matters not the top end power which was/is just an unwanted by product.
On that basis no the F88,F10 and the 290 ■■■■■■■ etc were really just development stages on route to the realisation of that ideal of a peak power output of at least 10 hp per tonne at around 2,000 rpm,being a reflection of the type of torque levels required,to produce the design aims of productivety combined with reasonable fuel economy.I think it is generally accepted amongst most operators that anything less than that power to weight ratio,isn’t efficient.
The only issue is the delay which occured during the 1970’s amongst most operators in realising that situation as opposed to manufacturers like Scammell and AEC who’d known it at least during the 500 ERGO’s production life while products like the Bedford TM and SA 400 and the argument between Leylands management and AEC’s concerning the 3VTG project,shows that the Brit manufacturers were also well aware of the development required in cab design to compete with the competition from the euro and scandinavian competition.The fact that the 500 powered ERGO and the TL12 powered Marathon and T45 made it into production,as opposed to the 3VTG cab and development of the Rolls powered Crusader instead and maybe a better developed T45 brought to the market sooner,really seems to have been an indictment of the backward thinking,amongst the domestic customer base,and the lack of funding and investment at Leyland in not being able to keep pace with the level of development know how contained amongst it’s workforce.However it’s an injustice that many people then try to blame that workforce for that situation.
Having said that I think that know how amongst the Leyland Group workforce was well aware that there was probably no way that the AEC engine range could have been made competitive with the outside sourced engine developments from Rolls and ■■■■■■■■■■■ TL12 being the only possible real contender with it’s outputs seeming to say everything about it’s probable potential,as opposed to those competitors.Although we’d only have kown for sure if the money invested in the development,production,and warranty claims regarding the 500 had been spent on the TL12 instead.
I’d be happy to drive aT45 cabbed motor today, a far better cab than Hino,Iveco or the Renaults that all the tipper boys are buying at the moment!btw I was around when the Ergo cab first came out we were gobsmacked it was light years ahead of the LAD cabbed Leylands & Park Royal cabbed AEC’sthat I worked on as an apprentice mechanic(having said that the LAD cab hung on for a good few more years)
Daf got the leyland 680 which become the tl 11 up to a 430 so theres no reason why the tl12 couldnt have gone further.
As nmm pointed out tbe 500 and tbe v8 aec debacle destroyed leylands engine reputation
Progress eh 
Some progress in many areas to do with trucks and their operation, but also plenty of regression in other areas. 
Whereas the Rolls was putting out around 300 hp at 2,000 rpm with sfc still under 230 at that output. 
