Out of intrest does anyone kbow was the tl12 at its limit at 280 bhp or was it a case of leylands financial postion been so bad by the early 80s they lacked funds for devolpment and was cheaper to offer ■■■■■■■ and rolls options.
perkins got the eagle up to 400bhp by the end of its engine life.
kr79:
Out of intrest does anyone kbow was the tl12 at its limit at 280 bhp or was it a case of leylands financial postion been so bad by the early 80s they lacked funds for devolpment and was cheaper to offer ■■■■■■■ and rolls options.
perkins got the eagle up to 400bhp by the end of its engine life.
There was a prototype inter-cooled TL12 320 under trial. It was cost that killed off the TL12. The early 1980s recession caused a big reduction in truck sales and British Leyland was already struggling to absorb the costs related with the T45 range development and launch. ■■■■■■■ and Rolls Royce engine options were cheaper than the in-house produced TL12.
I suppose that during the early 1970’s BL were also still trying to sort out (at great expense) the massive problems with the Bathgate made ex BMC 5.7 underfloor engine fitted in the FJ and Laird range that had been ongoing from 1964. They never did sort it until common sense prevailed and they fitted the engine vertically again! Must have cost a fortune in warranty claims though, I fitted THREE engines into a Laird and they all failed while still inside the workshop… 
Last thing they (BL) needed was yet another cr*p engine?
Pete.
gingerfold:
kr79:
Out of intrest does anyone kbow was the tl12 at its limit at 280 bhp or was it a case of leylands financial postion been so bad by the early 80s they lacked funds for devolpment and was cheaper to offer ■■■■■■■ and rolls options.
perkins got the eagle up to 400bhp by the end of its engine life.There was a prototype inter-cooled TL12 320 under trial. It was cost that killed off the TL12. The early 1980s recession caused a big reduction in truck sales and British Leyland was already struggling to absorb the costs related with the T45 range development and launch. ■■■■■■■ and Rolls Royce engine options were cheaper than the in-house produced TL12.
In general,assuming that an engine can be persuaded to deliver more power,without increasing engine speed to get it,that translates as more torque/ BMEP.Which means a more efficient engine.No manufacturer with any sense would walk away from an engine assuming that it’s got more potential in that regard.The key in that case being the strength in the design to accept the increased pressures involved without any compromise in long term durability.All the evidence points to the Rolls having a lot more potential in that regard than the TL12 did.IE the Rolls and ■■■■■■■ options were simply better/stronger designs with better development potential and hence better all round from both their manufacturers’ and customers’ point of view.At which point there was no longer any point in AEC/Leyland bothering any further with trying to get their existing compromised designs right.Even ‘if’ they’d have had the cash to do it which they didn’t considering that in the case of both the TL12 and the V8 it probably ( certainly in the case of the AEC V8 ) would have meant starting again from the drawing board.
Assuming that the TL12 was strong enough to accept an increase in BMEP figure by intercooling alone then what exactly were the supposed ‘extra costs’ in just making the switch to the intercooled version.Being that it would have meant no major re engineering of the basic design itself.The fact is it doesn’t seem to have even made it past the testing stage at that rating.The obvious question then being why. 
It wasn’t just the ‘costs’ of an increased power output TL12 that killed it off, it was the high unit costs associated with in-house engine production per se, in a large engine manufacturing plant that was operating way under its capacity. (300 units per week remember) Once you offer a truck model with optional engines than you are in effect diluting the potential sales for your own in-house engine. This trend had been set with the Marathon, firstly offering a ■■■■■■■ option to appeal to Guy Big J customers, and then extending the options to include Rolls Royce. Incidentally the latter options were considerably cheaper to the purchaser than both TL12 and ■■■■■■■ 250 powered models. Also if you can use bought-in engines, close your own engine making plant, make redundancies to save money then you can buy time to extend the life of the entire group. This was the scenario at BL in 1982-83 when TL12 production ceased, the final crunch time for the company was rapidly approaching and drastic decisions were taken.
gingerfold:
It wasn’t just the ‘costs’ of an increased power output TL12 that killed it off, it was the high unit costs associated with in-house engine production per se, in a large engine manufacturing plant that was operating way under its capacity. (300 units per week remember) Once you offer a truck model with optional engines than you are in effect diluting the potential sales for your own in-house engine. This trend had been set with the Marathon, firstly offering a ■■■■■■■ option to appeal to Guy Big J customers, and then extending the options to include Rolls Royce. Incidentally the latter options were considerably cheaper to the purchaser than both TL12 and ■■■■■■■ 250 powered models. Also if you can use bought-in engines, close your own engine making plant, make redundancies to save money then you can buy time to extend the life of the entire group. This was the scenario at BL in 1982-83 when TL12 production ceased, the final crunch time for the company was rapidly approaching and drastic decisions were taken.
All of which would need to be based on the premise that the Leyland Group and it’s customers weren’t increasingly looking at the ■■■■■■■ and Rolls engine alternatives because they were better,stronger designs with more potential in regards to outputs and efficiency.From what I knew first hand at Scammell,they didn’t walk away from the in house engines because the alternatives were cheaper.They were simply better ( with the exception of the ■■■■■■■ 903 in designs inherited from the Thornycroft takeover ).In which case if anyone with any sense was looking for a good 6 cylinder or V8 engine the Rolls and Detroit alternatives were firstly better.The fact that they ‘also’ might have been arguably cheaper too was an obvious bonus.The lesson being that one of the major flaws in the idea of reliance on in house engine supplies can be that getting it wrong in the form of a compromised ( lemon ) of an engine design has the potential to at least contribute in a major way in bringing the whole firm down. 
Whereas if a specialist engine supplier gets it wrong you just walk away and find a better alternative.
IE if you’re going to make your own engines then you’d better make sure that they are right first time every time and it helps if the price is right.It’s obvious that a specialist engine supplier has even more reason to get it right in that regard.Because unlike a non in house engine dependent manufacturer it can’t walk away from it’s mistakes by going somewhere else.
Carryfast:
Blah blah
He’s explained very well why TL12 production ceased, FFS: insufficient production volume to cover the cost of running the factory and insufficient funds to develop it further. Nothing to do with anything structural. How come everyone else can understand that at its first telling, yet you still fail to grasp it after repeated, laboured, explanations?
Look at the tl11 leyland never took it over about 250 bhp but daf got the same basic design over 400 bhp so its feesable that the tl12 had life in it.
I guess with the debacle of what happened through the 70s at BL Leyland knew it wasnt going to recover the customers Leyland and AEC lost in the UK or be a serious pan european player so it had to compete with erf foden and seddon atkinson for the people who still wanted a british lorry so fitting the ■■■■■■■ fuller rockwell driveline with a rolls option and they even offered gardners in the early constructors made sense.
I remember bewick posting somewhere erf told him he could have all the lorrys he wanted if he took rolls engines but maybe a 12-18 month for a gardner so were rolls going down the high production low profit on each unit and was there pressure as they were bailed out by the government in the early 70s.
[zb]
anorak:Carryfast:
Blah blahHe’s explained very well why TL12 production ceased, FFS: insufficient production volume to cover the cost of running the factory and insufficient funds to develop it further. Nothing to do with anything structural. How come everyone else can understand that at its first telling, yet you still fail to grasp it after repeated, laboured, explanations?
The difference is I don’t believe that ‘if’ the TL12 had a ( reliable ) 300-400 hp in it,without major re enginering,the Leyland Group as whole would have then bothered with going outside to ■■■■■■■ and Rolls for their 6 cylinder engine supplies.
As for sufficient funds what were the supposed suffcient funds required when we’re just being led to believe it was a case of using an inter cooler.
kr79:
Look at the tl11 leyland never took it over about 250 bhp but daf got the same basic design over 400 bhp so its feesable that the tl12 had life in it.
I guess with the debacle of what happened through the 70s at BL Leyland knew it wasnt going to recover the customers Leyland and AEC lost in the UK or be a serious pan european player so it had to compete with erf foden and seddon atkinson for the people who still wanted a british lorry so fitting the ■■■■■■■ fuller rockwell driveline with a rolls option and they even offered gardners in the early constructors made sense.
I remember bewick posting somewhere erf told him he could have all the lorrys he wanted if he took rolls engines but maybe a 12-18 month for a gardner so were rolls going down the high production low profit on each unit and was there pressure as they were bailed out by the government in the early 70s.
The inconvenient truth is the 680 was re engineered by DAF to the point where it was arguably effectively a different engine.IE Leyland got the original design wrong with no money left to put it right.Unlike DAF who had the required cash to fix it.With the advantage of the required knowledge to do so being available to them with the benefit of hindsight gained at the expense of Leyland.
As for the TL12 v the Eagle there’s one obvious difference even in that case which is relevant.Being that the Eagle’s designer chose a 6 inch stroke measurement as opposed to the TL12’s 5.5 inch.Which gives the thing an obvious torque advantage for any given level of boost.IE more torque for equivalent boost or more importantly less boost required to get equivalent torque.The same applied in the case of the 14 litre ■■■■■■■■
Im not an engineer or pretend to know about stroke and oversquare designs just putting across a feesable alternative.
kr79:
Im not an engineer or pretend to know about stroke and oversquare designs just putting across a feesable alternative.
Let’s just say that my pay grade and status was ( way ) below that of the firm’s design engineers.But even myself or the average shop floor worker in AEC’s engine department with anything remotely linked to the word ‘engineer’ being part of the job description,would have been expected to understand the importance of the link between a decent stroke measurement and torque characteristics of an engine.To put it simply there’s three main ways to make torque in that you either apply a longer lever at the crank or you apply more pressure to the piston.Or preferably an optimum combination of both in which case the limiting factor then is how much pressure the engine componentry and head to block clamping/seal can stand before something lets go.By that comparison it’s obvious that the more leverage you can apply at the crank the less pressure you’ll need to apply to the piston.What you don’t do is compromise on the leverage leaving yourself with the only way out of more pressure on the piston to compensate for the shortfall.
Once I was able to afford to move up the scale as regards vehicle quality I started buying ■■■■■■■ engined Atky and ERF’s (not forgetting a few Guy Big J’s 
) “kr79” was quite right about the comment that Peter Foden made about the best favour us hauliers could do him would be to buy ■■■■■■■ or RR powered Chassis but unfortunately we were in a tough game and economy and reliability came at the top of our list although while the ■■■■■■■ was extremely reliable they weren’t the most economic,well not compared to the Gardners any way (I can just imagine “CF” trying to persuade Matron to let him out of his straight jacket at this very moment 
)The RR engine or anything Leyland engined was never an option as far as I was concerned they were absolute rubbish and failed on every comparison with the Gardner or ■■■■■■■ (205/220 only)IMHO.Well that was my policy many had different ideas and were often tempted into buying RR and Leyland engined motors but I never weakened in my resolve never to join them 
Cheers Bewick.
A place i used to work had a fitter who in the 60s and 70s had worked for the big london tipper firm drinkwater whos favoured 8 wherler and artic was a gardner powered foden said they would buy new fodens with ■■■■■■■ leyland or fodens own two stroke and re engine them with Gardners such was there faith in the product and it must have made economic sense to them to do that and i believe this wasnt an uncommon situation.
Bewick:
Once I was able to afford to move up the scale as regards vehicle quality I started buying ■■■■■■■ engined Atky and ERF’s (not forgetting a few Guy Big J’s
The important bit is that like the ■■■■■■■ and Rolls the Gardner used a 6 inch stroke measurement.The difference is the Gardner didn’t combine that with an ‘optimum’ amount of pressure on the piston.Hence an engine which didn’t need much fuel,was so low stressed that it would run forever and last but not least had a zb BMEP figure.So that fuel consumption and reliability was obtained at the expense of efficiency.Hence why the Scania V8 is still around in improved longer stroke form but the Gardner is ( rightly ) history.
The modern scania 15.6 and the later 16.4 v8 is no relation to the original 14.2 v8 other than the v8 configuration.
kr79:
The modern scania 15.6 and the later 16.4 v8 is no relation to the original 14.2 v8 other than the v8 configuration.
Or to put it another way if only I’d have been born earlier and if I’d have been working for AEC in 1962 I’d have told them to make the AEC V8 with a 16.4 litre overall capacity with a 6 inch stroke.If they’d have listened to me nmm,zb and Bewick would have said they are mad. 
You are as silly as a box of frogs Geoffrey 
Billions of miles have helped development of the current V8 from Scania, it has a modular design to keep production costs down and has a very loyal fanbase that ensure it remains in production. You can hardly compare the two.
When the 140 was launched it was a very different time, yes they started with a decent design, but it wasn’t a patch on the current V8.
You also seem to forget the teal success story when it comes to V8 diesel engines.
Any idea which one I’m referring to 
From my own experience of TL12 engined Roadtrains with Spillers Milling, (we had over 40 of them in the group). there were no reliability issues and believe me they were 100% better than the TL11 Buffalos they replaced. The drivers loved them, they were fast and from an operational point of view were as economical on fuel as anything else we had with a similar power output. Because we were using blowers with them for discharging tankers of flour actual mpg figures were hard to quantify, but they were overall (including blowing time) an average 0.75 mpg better than the ■■■■■■■ powered Roadtrains that came after the TL12 was discontinued. We had a couple of Rolls Royce 265 powered eight wheelers which were OK but nothing to write home about from a driving viewpoint.
Bear in mind most long standing operators, whether hire and reward, or own account, were conservative in their buying policy and tended to stick with what they knew, whether it be Leyland, AEC, Gardner et al., despite disasters they encountered. Take Spillers as a prime example, they stuck with Leyland / AEC/ Guy through thick and thin. It was difficult for a new supplier coming into the market, such as ■■■■■■■■ Rolls Royce, Volvo, Scania etc, as they all were at one time, to break into the long established fleets unless they offered incentives such as cheaper prices, quicker supply lead times, imjproved after sales service, and of course a better product, the latter taking the longest timescale to establish. Bewick is an interesting case, his was a new company at a time when all these massive changes were happening, initially he was conservative in his buying policy, but soon became open minded enough, and even adventurous to go to Scania. I hope that he doesn’t mind me commenting thus, but he thought independently and reaped the benefits.
newmercman:
You are as silly as a box of frogs GeoffreyBillions of miles have helped development of the current V8 from Scania, it has a modular design to keep production costs down and has a very loyal fanbase that ensure it remains in production. You can hardly compare the two.
When the 140 was launched it was a very different time, yes they started with a decent design, but it wasn’t a patch on the current V8.
You also seem to forget the teal success story when it comes to V8 diesel engines.
Any idea which one I’m referring to
I thought you’d say something like that.
‘Production costs’ don’t get much more expensive than the type which cause compromise,to the point of rendering a design effectively useless,on something as basic as the overall capacity and stroke measurement of a design which the firm has bet most of the farm on.As I’ve said any decent ‘engineer’ a lot lower down the order than design level,even in 1962,would have known that the original Scania V8 wasn’t as good as it could get and that the measurements,in that regard,that they’ve chosen now are close enough.IE it took them more than long enough to reach an ideal.Based on basic knowledge which has been around since the invention of the internal combustion engine and probably before in the case of steam.
As for the really silly thinking behind the short stroke ■■■■■■■ and AEC V8’s and even the relatively short stroke TL12 v it’s 6 cylinder opposition,who knows. 
But typically dastardly German spoiling/sabotage tactics seem to be one possibility which the Americans and Brits were then stupid enough to fall for.
As for the ‘real’ success story,in engineering terms,in regard to the type of heavy truck V8 diesels being discussed in the topic.As I’ve said you can count them on one hand.8V71/92,Cat 3408,Scania V8 and the FIAT.I’d put the Fiat at the bottom of the list and I’d put the Cat at the top for at least having the ideal measurements regarding that all important stroke measurement.Although I’m guessing that you will know why the 8v71/92 can punch way above it’s weight in that regard.
While ironically even it’s driver doesn’t seem to understand the importance and significance of stroke as opposed to bore in this case.