Unusual retro-fitted high roof on a 2800. Robert
Bewick:
IMHO as a former operator of many motors the DAF was crap compared to the Scania and Volvo and DAF only competed on price,we ran a number of DAF demos over the years at Bewick Transport and neither I nor the drivers that were swapped about on them rated them, in fact the odd driver on a ten year old Scania which was docked for overhaul could not wait to get back onto it and off the Poxy DAF ! I kid you not ! Cheers Bewick.
What type of ‘DAF’ v what type of Volvo or Scania.On that note I still preferred driving the old 1978 2800 to the 112 or F10 and FL10 at least.While the 3300 or 3600 were obviously in a different league to that assuming a Fuller box option in them. 
Carryfast:
Bewick:
IMHO as a former operator of many motors the DAF was crap compared to the Scania and Volvo and DAF only competed on price,we ran a number of DAF demos over the years at Bewick Transport and neither I nor the drivers that were swapped about on them rated them, in fact the odd driver on a ten year old Scania which was docked for overhaul could not wait to get back onto it and off the Poxy DAF ! I kid you not ! Cheers Bewick.
What type of ‘DAF’ v what type of Volvo or Scania.On that note I still preferred driving the old 1978 2800 to the 112 or F10 and FL10 at least.While the 3300 or 3600 were obviously in a different league to that assuming a Fuller box option in them.
Well, CF, take heart! The 2800s had 13-speed Fullers, as did the Turk-spec 3300s and even some of the Belgian DAF 95s, according to Eric (Tip-top). Plus, we know that UK-spec DAF 2800 DKSEs had 9-speed Fullers; and that early DAF 85s had Eaton Twin-splitters (apparently, a very good installation). Talking of installation: I reckon that DAF were brilliant at gearbox installation: they must have been to make such a good job of converting the crappy ZF-Ecosplit synchro box into such a useable piece of equipment (as we discussed, CF, and agreed earlier). And by the way, some years ago I took a DAF CF rigid 'fridge lorry on multi-drop round London and it had a straight 9-speed ZF synchro box: it was superb - quite the best synchro box I think I’ve ever used. You’ve got to hand it to DAF: they did make gearboxes work! Robert
I have just remembered while reading this that we had a DAF eightlegger on demo back in the late 70’s when I was at Tilcon while Fodens were in short supply, the driver seemed to like it better than his regular Foden S39. Haven’t a clue what model it was though. Of course we never bought any, ended up with a few blooming Sed Ak’s instead.
Pete.
robert1952:
Well, CF, take heart! The 2800s had 13-speed Fullers, as did the Turk-spec 3300s and even some of the Belgian DAF 95s, according to Eric (Tip-top). Plus, we know that UK-spec DAF 2800 DKSEs had 9-speed Fullers; and that early DAF 85s had Eaton Twin-splitters (apparently, a very good installation). Talking of installation: I reckon that DAF were brilliant at gearbox installation: they must have been to make such a good job of converting the crappy ZF-Ecosplit synchro box into such a useable piece of equipment (as we discussed, CF, and agreed earlier). And by the way, some years ago I took a DAF CF rigid 'fridge lorry on multi-drop round London and it had a straight 9-speed ZF synchro box: it was superb - quite the best synchro box I think I’ve ever used. You’ve got to hand it to DAF: they did make gearboxes work! Robert
I’d guess what could actually be supplied was more a case of whatever the customer demanded rather than being strictly based on geographic market areas or publicised spec sheets.As I’ve said we certainly had a 3300 spec engine,admittedly supplied mistakenly by the factory,in what ( should have been ) a 2800 ATI,together with the 9 speed Fuller. 
While from memory I don’t think that even the stated UK market 3300 was necessarily mutually exclusive with the 13 speed Fuller if anyone wanted to push the issue.Nor was the DKS version mutually exclusive with the ZF constant mesh 12 speed splitter as in commonly provided spec literature.Which we’ve managed to confirm elsewhere with an obscure European advert.IE DAF could/did obviously provide some generally available decent transmission options which the Scandinavians couldn’t/wouldn’t at least in Euroland.On that note it’s possible that DAF ‘had’ to make their synchro options work as well as possible by necessity so as not to alienate a customer base that associated DAF with decent constant mesh shift quality.Probably having learned their lesson with the diabolical 12 speed synchro in the 2500 in that regard. 
While the 680 based 11.6 engine seemed to be able to hold its own throughout its development history against the Volvo F12 let alone the F10. Together with reasonably comparable cab comfort in both 2800-3600 and 95 form.Make no mistake Leyland had and let go a special motor in the 680 which DAF then developed to ultimate effect.Without which I doubt that DAF would have got through the 1970’s let alone more.
While Leyland kept and tried to develop the flawed shorter stroke TL12.The rest is history.
Carryfast:
…Make no mistake Leyland had and let go a special motor in the 680 which DAF then developed to ultimate effect.Without which I doubt that DAF would have got through the 1970’s let alone more…
Other threads point to reliability differences between the original O680 and Power Plus P680, in that the former was good and the latter was bad, for reliability. What Leyland “let go” was the ability to design and develop engines which were competitive. The rest of the world edged ahead between the introduction dates of those two 680 variants. Leyland remained a typical British manufacturer, with blacksmiths in the design office, while DAF (and Scania Vabis, and the rest) had the foresight to get some brains up top. The rest is, indeed, history- who would have thought that the way to improve the unreliable P680 was to increase its capacity, then tune the inlet tracts, then add a turbocharger? In 1965, this would have sounded like the words of a lunatic, yet those clever Dutchmen knew better.
That is a slight over-simplification, of course. There has been more detailed discussion of the reliability of the various DAF 1160 engines, possibly from the inestimable experience of Tiptop495. IIRC, the DP680 was no better than the Leyland P680, but the DKS was excellent. Somewhere in between, DAF’s engineers edged ahead.
The DAF MX engine is now the “in-house” Paccar engine, as that company gradually becomes vertically integrated. In my humble opinion, that makes Eindhoven one of the engine design capitals of the world.
[zb]
anorak:Carryfast:
…Make no mistake Leyland had and let go a special motor in the 680 which DAF then developed to ultimate effect.Without which I doubt that DAF would have got through the 1970’s let alone more…Other threads point to reliability differences between the original O680 and Power Plus P680, in that the former was good and the latter was bad, for reliability. What Leyland “let go” was the ability to design and develop engines which were competitive. The rest of the world edged ahead between the introduction dates of those two 680 variants. Leyland remained a typical British manufacturer, with blacksmiths in the design office, while DAF (and Scania Vabis, and the rest) had the foresight to get some brains up top. The rest is, indeed, history- who would have thought that the way to improve the unreliable P680 was to increase its capacity, then tune the inlet tracts, then add a turbocharger? In 1965, this would have sounded like the words of a lunatic, yet those clever Dutchmen knew better.
That is a slight over-simplification, of course. There has been more detailed discussion of the reliability of the various DAF 1160 engines, possibly from the inestimable experience of Tiptop495. IIRC, the DP680 was no better than the Leyland P680, but the DKS was excellent. Somewhere in between, DAF’s engineers edged ahead.
The DAF MX engine is now the “in-house” Paccar engine, as that company gradually becomes vertically integrated. In my humble opinion, that makes Eindhoven one of the engine design capitals of the world.
It seems obvious that the development of the DKS wasn’t ever going to be as simple as just bolting a load of turbocharging kit to the old 680.In this case the bit that DAF rightly seemed to foresee,as opposed to Leyland,was the basic foundations,as I said,between the 680’s stroke v the TL12 at least in addition to other ability of the design to be re engineered to the required level.On that note it was probably more a case of a DAF engineering v AEC fight with Leyland still,at that time,being over dependent on/lumbered with AEC’s typically flawed thinking in that regard.In which case it really wasn’t/isn’t rocket science to understand the advantages v the disadvantages of the 680 ( DKS ) v the TL12.Which was really the simple choice which the fortunes of Leyland v DAF came down to.Not to mention 2800 and 95 cab v T45.
IE Leyland lost the fight because of choices which should have been clear even at school leaver level and/or gave up and threw in the towel knowing that the required development cash wasn’t there anyway.Assuming the latter wasn’t the case the whole fiasco could only logically have been an attempt to wrong foot the competition by palming them off with ( what AEC thought ) was an inferior Leyland design while keeping what they thought would become the wonder weapon in the form of the TL12.Which obviously backfired catastrophically. 
When as I’ve said school leaver level automotive engineering knowledge would/should have said exactly the opposite by giving DAF the AV760/TL12 and doing exactly what DAF did with the 680.It’s my bet that DAF would have walked away in that case.
The new MX engine as fitted to the CFs is a lovely piece of kit. Not too noisy and not too quiet. I had a 440 version on demo and loved it, even with an auto 'box. The manual 'boxed 400 variant isn’t thought of greatly according to a mate at Earthline.
Talking of Leyland origins, my Dad always liked the Leyland TL11 as fitted to the early Constructors. It was the rest of it the lorry he didn’t like.
I wonder how DAF would have fared if they had been gifted the 12.4 litre AV760 instead of the 11.1 litre Leyland 680. In reality they would probably have had to develop the 11.3 litre AV690 if the time scale had been the same. However AEC had already bored out the AV 690/691 from 130mm to 136mm and that is the engine size we are being asked to compare.
The Article below describes how Leyland managed to increase the stroke of their 9.8 litre 600 engine 122 x 140 by 6mm to produce the 680 (127x146).
To produce the AV 760 AEC increased the bore size by 6mm to give dimensions of 136 x142. When DAF developed their 11.6 DK engine from the Leyland 680 they increased the bore size by 3 mm. Had they received the larger bored AV 760 AEC engine instead, and copied Leyland’s idea of stroking the engine then an increase of 6mm would have given them a small improvement, however to take it any further would have seen them having significant difficulties. The Leyland crankshaft centre line is buried within the block, whereas the AEC centre line is flush with the sump face.
However if successful they would have ended up with a very similar bore/stroke ratio as the ■■■■■■■ 14 litre.
cav551:
I wonder how DAF would have fared if they had been gifted the 12.4 litre AV760 instead of the 11.1 litre Leyland 680. In reality they would probably have had to develop the 11.3 litre AV690 if the time scale had been the same. However AEC had already bored out the AV 690/691 from 130mm to 136mm and that is the engine size we are being asked to compare.The Article below describes how Leyland managed to increase the stroke of their 9.8 litre 600 engine 122 x 140 by 6mm to produce the 680 (127x146).
To produce the AV 760 AEC increased the bore size by 6mm to give dimensions of 136 x142. When DAF developed their 11.6 DK engine from the Leyland 680 they increased the bore size by 3 mm. Had they received the larger bored AV 760 AEC engine instead, and copied Leyland’s idea of stroking the engine then an increase of 6mm would have given them a small improvement, however to take it any further would have seen them having significant difficulties. The Leyland crankshaft centre line is buried within the block, whereas the AEC centre line is flush with the sump face.
However if successful they would have ended up with a very similar bore/stroke ratio as the ■■■■■■■ 14 litre.
I’d guess that’s the type of dilemma that DAF was looking at and rightly decided that a larger bore 680,although still less than the 760’s,trumps the idea of trying to stroke something like the 760 to at least the equivalent of the 680 or preferably more.What we do know is that,what seems to have been an ex AEC engineer,probably decided that AEC’s designs were a lost cause in that regard and jumped ship and designed the longer stroke Rolls Eagle. Which was put to great effect in the T45 but obviously didn’t fit the idea of in house engine production.The question being that surely,as I’ve said,even the lowest grade trainee shop floor worker at Leyland would have been expected to realise that developing the 680 as DAF did was the way to go to meet the required compromise of an in house motor that stood a chance of doing the job.
Which leaves the question was the XF a further stroked development of the 11.6 DK/WS block ( what seems like 130 x 158 for the XF and then 162 respectively for the MX 13 ? ) ,that ideally Leyland could also have made from day 1 had things turned out differently and had that Rolls designer have stayed at AEC and it had been DAF that ended up with the blind alley of the TL12 not Leyland and vice versa regards the 680.Bearing in mind that an increase in stroke is proportionally more beneficial,regards obtaining a relatively more unstressed torque output,than increasing bore size.
There is a bit about Leyland ‘trainees’ the 680 and 500 engines and Whitworth threads in this link by a rather self opinionated author methinks:
cav551:
There is a bit about Leyland ‘trainees’ the 680 and 500 engines and Whitworth threads in this link by a rather self opinionated author methinks:
Let’s use an 8 litre engine to do the job of what would ideally be 12 litres + with a 6 inch or more stroke that’ll work. 
Although to be fair DAF did try to do something similar with the 2300/2500 or at least the punters who bought them did.
I would be intrigued to find out how DAF rectified the (minor) problem Leyland had with gaskets on the 680 which was due (some believe) to insufficient depth on the top deck of the block for the studs to get sufficient pull to hold the cylinder heads down tightly.
Some operators drilled out the stud holes in the block and put in stepped studs with the larger end screwed into the block. As far as I know, DAF did not use stepped studs.
Can someone comment?