ramone:
So Anorak could the TL12 if the money was available be developed into a more powerful engine we have been told 320bhp was achieved could they have gone further?
No reason not, given the available information. Compressive loads 7% higher than 6" stroke engines is nothing, compared to the increase in compressive loads achieved in the 1980s, in all engines. With an ordinary development programme, it would have gone 320 in 1983, 360 in '86 then 400 in 1990. If GB had wanted home-owned vehicle manufacturing in the long term, that would have given it ample time to create a completely new engine for the 1990s onward. It seems they threw in the towel, some time in the early 1980s, hence abandoning their vertically-integrated ambitions and allowing things to peter out.
No chance ! Rumour has it that Maggie would have had the engineers shot.
ramone:
So Anorak could the TL12 if the money was available be developed into a more powerful engine we have been told 320bhp was achieved could they have gone further?
No reason not, given the available information. Compressive loads 7% higher than 6" stroke engines is nothing, compared to the increase in compressive loads achieved in the 1980s, in all engines. With an ordinary development programme, it would have gone 320 in 1983, 360 in '86 then 400 in 1990. If GB had wanted home-owned vehicle manufacturing in the long term, that would have given it ample time to create a completely new engine for the 1990s onward. It seems they threw in the towel, some time in the early 1980s, hence abandoning their vertically-integrated ambitions and allowing things to peter out.
No chance ! Rumour has it that Maggie would have had the engineers shot.
They had a long history of leading innovation- the C40 and C44 cabs were copied extensively for the next 20 years. If Tony Benn had been in charge (IIRC, from reading Michael Edwardes’ autobography, Mr. Benn was good for business, if business was good for Britain), who knows what they could have achieved? archive.commercialmotor.com/arti … 2/roadtest
A 2000Nm TL12 would have had similar nominal compressive loads to the 1990 Scania 400.
Re: the Rolls Eagle 220 vs the 280 in the Crusader; and the mindset of operators at 32 tons of that period: here it is from the horse’s mouth. This is what BL/Scammell’s market research told them was going to sell.
[zb]
anorak:
…
The head bolt loads are proportional to the peak torque. A longer stroke means lower head bolt loads. Do you agree? Y/N.
The head bolt loads are proportional to torque made by force on the piston/con rod .
So we can agree that, the more torque a given engine makes, the loads on the head bolts will be higher?
Carryfast:
A longer stroke means equivalent or more torque made by multiplying less or the equivalent force by more leverage so YES a longer stroke means lower head bolt loads and lower end bearing loads.
Good. I like that.
Head bolt loads (and other compressive loads, therefore) are proportional to the torque output, and inversely proportional to the stroke. Bringing these two together, we have:
F=kT/S, where k is the proportionality constant. Are we still on the same hymn sheet?
As some of you appear to have more time on your hands than me, would one of you be kind enough to find out the bore/stroke ratio and capacity of all the engines producing similar output to the TL12, between 1970 and 2000 should give a broad enough spectrum and let’s include American (north and south) and Asian engines too.
I’m quite sure there will be some very interesting comparisons.
ramone:
So Anorak could the TL12 if the money was available be developed into a more powerful engine we have been told 320bhp was achieved could they have gone further?
No reason not, given the available information. Compressive loads 7% higher than 6" stroke engines is nothing, compared to the increase in compressive loads achieved in the 1980s, in all engines. With an ordinary development programme, it would have gone 320 in 1983, 360 in '86 then 400 in 1990. If GB had wanted home-owned vehicle manufacturing in the long term, that would have given it ample time to create a completely new engine for the 1990s onward. It seems they threw in the towel, some time in the early 1980s, hence abandoning their vertically-integrated ambitions and allowing things to peter out.
No chance ! Rumour has it that Maggie would have had the engineers shot.
ramone:
So Anorak could the TL12 if the money was available be developed into a more powerful engine we have been told 320bhp was achieved could they have gone further?
No reason not, given the available information. Compressive loads 7% higher than 6" stroke engines is nothing, compared to the increase in compressive loads achieved in the 1980s, in all engines. With an ordinary development programme, it would have gone 320 in 1983, 360 in '86 then 400 in 1990. If GB had wanted home-owned vehicle manufacturing in the long term, that would have given it ample time to create a completely new engine for the 1990s onward. It seems they threw in the towel, some time in the early 1980s, hence abandoning their vertically-integrated ambitions and allowing things to peter out.
But the compressive loads weren’t just ‘7% higher’.First you have to add the higher torque requirement from the 860.Then apply the leverage deficit to the sum of that ?.
If the TL12 was capable of being developed to those types of output they’d had since 1973 to do it just like RR with the ‘320’ heading for ‘340’ and finally 400.
Why would you want to even try when the RR is already there and paid for.It’s the question why let RR go in '79 instead of bringing it ‘in house’ obviously at no charge because the tax payer owns them both.
Which is the smoking gun that the government always intended to close Leyland and with it AEC and Scammell from that point in time , not Stokes.
They didn’t want the Roadtrain to succeed as part of that plan but they did want to get the development budget back or as much of it as possible.
newmercman:
As some of you appear to have more time on your hands than me, would one of you be kind enough to find out the bore/stroke ratio and capacity of all the engines producing similar output to the TL12, between 1970 and 2000 should give a broad enough spectrum and let’s include American (north and south) and Asian engines too.
I’m quite sure there will be some very interesting comparisons.
It was its ( specific ) ‘output’ which was its problem.
The argument is about the best solution to increasing it.
If we can include North American designs we can obviously start with Maxidyne v TL12, ■■■■■■■ ISX v N14 and Detroit 60 series 14.litre v 12.7 v 11.1 , CAT C15 v 3406.
Europe DAF DK 11.6 v XE 12.6 says it all in the Leyland context and ironically shows that they weren’t happy with the 11.6’s architecture.
Obviously cash not engineering ideals was the limiting factor stopping them up to that point including a government bail out.
No such excuse for Leyland in the case of trashing an RR takeover.
The RR takeover is a figment of CFs immagination not a real thing i would doubt very much that it was even considered when the name of the game when Edwards took over was rationalisation and cost cutting . Why on earth would they take on another loss making company when they were in the process of a massive cost cutting programme , also they could call off the supply from RR when the orders come in rather than building engines they might not be able to sell when customers may prefer a ■■■■■■■ . A RR take over wouldn’t be a free transaction there would be massive cost incurred
Why would anyone back then (early 80’s) choose a RR over the TL12 , RR were heavy on fuel and regulary had to be rebuilt, if CF had ever done one he would be ■■■■■■ off having to remove the
new pistons out of the block after measuring the protrusion, then would have to wait for them to come back from machining, then after about four weeks of running having to be stripped
down again to fit the lower control rings, RR were cheap fuel drinking nasty engines back then, and yes I know they did go well when wound up.
Apart from one TL12 in the fleet I worked with back in the mid 80’s the rest were pretty trouble free, the RR engines on the other hand were constantly in & out of the workshop.
[zb]
anorak:
…
The head bolt loads are proportional to the peak torque. A longer stroke means lower head bolt loads. Do you agree? Y/N.
The head bolt loads are proportional to torque made by force on the piston/con rod .
So we can agree that, the more torque a given engine makes, the loads on the head bolts will be higher?
Carryfast:
A longer stroke means equivalent or more torque made by multiplying less or the equivalent force by more leverage so YES a longer stroke means lower head bolt loads and lower end bearing loads.
Good. I like that.
Head bolt loads (and other compressive loads, therefore) are proportional to the torque output, and inversely proportional to the stroke. Bringing these two together, we have:
Force = k x T/S, where k is the proportionality constant. Are we still on the same hymn sheet?
Are we happy to agree with the above general idea? The compressive forces increase with more torque, are reduced by increasing the stroke? That seems to be what you have been saying all along.
ramone:
The RR takeover is a figment of CFs immagination not a real thing i would doubt very much that it was even considered when the name of the game when Edwards took over was rationalisation and cost cutting .
I never said it was considered that’s my point.
Rationalisation doesn’t mean trashing and closing the firm to the advantage of the foreign competition.
It means doing stuff like knocking a no hoper motor on the head and bringing in a free and better one.Which part of there was no ‘cost’ in doing that because the government/taxpayer owned both firms didn’t you understand.
Picture the scene at Scanmmell when Edwardes told them there’d be no RR in the T45.Oh and the government has given it away to Vickers anyway.
WTF would have been the justified united cry.You’re taking us all out with this piece of junk.
You know the same piece of junk that they’d effectively refused to use since it was introduced.
ERF-NGC-European:
Re: the Rolls Eagle 220 vs the 280 in the Crusader; and the mindset of operators at 32 tons of that period: here it is from the horse’s mouth. This is what BL/Scammell’s market research told them was going to sell.
0
It would be reasonable to say that whole premise was obsolete by the mid 1970’s let alone 1979.
Make no mistake things were moving at lightning pace in that regard during the 1970’s and there was no place for outdated thinking and not keeping pace in what was a race for survival against the competition.
It’s obvious that CM’s road test was rightly making the case for vehicles like the DAF DKS on domestic UK work in its road test of the mid 1970’s.
All obviously moot assuming a deliberate agenda of gradual run down and closure by stealth to the advantage of that competition.The ‘marketers’ would have been ‘in’ on it told what to say on the basis of who pays the piper calls the tune.
I think we saw a clear agreed plan of deindustrialisation of the country turning it into a services based economy not a manufacturing based one to be delivered by the 1980’s.
The government made no secret of that as it got towards its end game.
[zb]
anorak:
Are we happy to agree with the above general idea? The compressive forces increase with more torque, are reduced by increasing the stroke ? That seems to be what you have been saying all along.
Agreed.I’ve just been saying ‘increasing the stroke’ as replacing force with more leverage instead.
If you want to apply 1,216 lbft instead of 860 to something you don’t want to be using a shorter bar for the job.You want the longest one you can find ?.Are we agreed ?.
Then we can continue with what actually happened in Edwardes’ actual plan.That ended well as usual.
[zb]
anorak:
…No reason not, given the available information. Compressive loads 7% higher than 6" stroke engines is nothing…
But the compressive loads weren’t just ‘7% higher’.First you have to add the higher torque requirement from the 860.Then apply the leverage deficit to the sum of that ?..
You’re right up to “apply the leverage deficit.” More force, less leverage or less force, more leverage is the balance. You can’t account for one of the parameters twice.
The equation Force= k x T/S, that I used to summarise the correct part of your theories so far, can be manipulated as you wish:
Pressure= Force/Area, therefore Force= P x A
Volume= A x S, where A is the piston area (obviously, to put that into any of the other expressions, you need to account for six cylinders).
[zb]
anorak:
…No reason not, given the available information. Compressive loads 7% higher than 6" stroke engines is nothing…
But the compressive loads weren’t just ‘7% higher’.First you have to add the higher torque requirement from the 860.Then apply the leverage deficit to the sum of that ?..
You’re right up to “apply the leverage deficit.” More force, less leverage or less force, more leverage is the balance. You can’t account for one of the parameters twice.
The equation Force= k x T/S, that I used to summarise the correct part of your theories so far, can be manipulated as you wish:
Pressure= Force/Area, therefore Force= P x A
Volume= A x S, where A is the piston area (obviously, to put that into any of the other expressions, you need to account for six cylinders).
Surely a leverage deficit is exactly what you’ve got.You want to go from 69 lbft per litre to 100 lbft per litre with a shorter lever than your competitors.What I’ve seen so far is the excuse that they aren’t your competitors if you can’t match them.That’ll work.
More piston area means less cylinder pressure required for the same force but it doesn’t do anything to reduce the resulting loads on the cylinder head fastenings or end bearings.
Effectively you either use a longer bar for more leverage.
Or you have to try to rely on just the head bolts tensile strength holding to maintain the head to block seal and trying to use more force on the con rod trying to push it through the sump with the small end and the upper big end shell being crushed against the con rod and crankshaft standing in its way.
Bearing in mind the force spread across the much larger piston and head area is then imposed as tension on the head bolts and force on the much smaller area of the small end and the big end bearing shell.
Basically if a ‘short bar’ is being used to make more torque it’s for a bad reason.There is no upside to it.
In the case of TL12 what worked in a 7.5t gross bus wasn’t going to work when we want 100 lbft per litre to pull a 32t artic along.
I really don’t believe that AEC’s designers didn’t know that and I’m guessing the laughable increase from the 590’s bore stroke ratio wasn’t done by choice or for any good reason.Other than someone said no you can’t have a 154 or 156 mm stroke crankshaft let alone a new engine block/crank case to house it.
Not because the money wasn’t there but because there were numerous foreign interests who would have been trashed by it when it hit the road.Not least ■■■■■■■ UK.
I suppose you realise that you are ■■■■■■■ ruining TNUK “CF” quite apart from winding up the likes of “ramone” and “zb” anorak who havn’t got the same access to Horse Tranquilizer like what Matron dispenses to you every night ! “Now come on Geoffrey be a good boy and swallow it or I wont leave go of your bollox until you do” But I’ve got to give it to “CF” you certainly can make the ■■■■■■■ teeth itch you sure can ! Cheers Bewick.
[zb]
anorak:
…No reason not, given the available information. Compressive loads 7% higher than 6" stroke engines is nothing…
But the compressive loads weren’t just ‘7% higher’.First you have to add the higher torque requirement from the 860.Then apply the leverage deficit to the sum of that ?..
You’re right up to “apply the leverage deficit.” More force, less leverage or less force, more leverage is the balance. You can’t account for one of the parameters twice.
The equation Force= k x T/S, that I used to summarise the correct part of your theories so far, can be manipulated as you wish:
Pressure= Force/Area, therefore Force= P x A
Volume= A x S, where A is the piston area (obviously, to put that into any of the other expressions, you need to account for six cylinders).
Surely a leverage deficit is exactly what you’ve got.You want to go from 69 lbft per litre to 100 lbft per litre with a shorter lever than your competitors.What I’ve seen so far is the excuse that they aren’t your competitors if you can’t match them.That’ll work.
More piston area means less cylinder pressure required for the same force but it doesn’t do anything to reduce the resulting loads on the cylinder head fastenings or end bearings.
Effectively you either use a longer bar for more leverage.
Or you have to try to rely on just the head bolts tensile strength holding to maintain the head to block seal and trying to use more force on the con rod trying to push it through the sump with the small end and the upper big end shell being crushed against the con rod and crankshaft standing in its way.
Bearing in mind the force spread across the much larger piston and head area is then imposed as tension on the head bolts and force on the much smaller area of the small end and the big end bearing shell.
Basically if a ‘short bar’ is being used to make more torque it’s for a bad reason.There is no upside to it.
In the case of TL12 what worked in a 7.5t gross bus wasn’t going to work when we want 100 lbft per litre to pull a 32t artic along.
I really don’t believe that AEC’s designers didn’t know that and I’m guessing the laughable increase from the 590’s bore stroke ratio wasn’t done by choice or for any good reason.Other than someone said no you can’t have a 154 or 156 mm stroke crankshaft let alone a new engine block/crank case to house it.
Not because the money wasn’t there but because there were numerous foreign interests who would have been trashed by it when it hit the road.Not least ■■■■■■■ UK.
Apart from the political intrigue, are you happy to agree that the compressive loads on the head bolts and rod end bearings are proportional to the torque output?
Are you happy to agree that, the longer the stroke, the lower those loads are?
Bewick:
I suppose you realise that you are [zb] ruining TNUK “CF” quite apart from winding up the likes of “ramone” who hasn’t got the same access to Horse Tranquilizer like what Matron dispenses to you every night ! “Now come on Geoffrey be a good boy and swallow it or I wont leave go of your bollox until you do” But I’ve got to give it to “CF” you certainly can make the [zb] teeth itch you sure can ! Cheers Bewick.
Just think what might have been if the Gardner 8 LXB had been designed with a 142 mm stroke.
