ramone:
This is a question from someone who knows absolutely nothing about gearbox or engine workings ,but wasnt the AEC boxes a slow change, wasnt the old saying you could roll a cig up whilst changing up . I`m thinking that you would lose momentum whilst waiting for the revs to drop or am I missing something … I have my hard hat on
On an up-change yes it was slow. On a down-change as fast as you like, same as most constant mesh 'boxes.
ERF-NGC-European:
ERF:
ERF-NGC-European:
Much as I admire Fuller gearboxes, it seems strange to me that AEC didn’t further develop the excellent Thornycroft gearbox technology at their disposal. Everyone I’ve ever talked to who used the later constant-mesh 6-speed (12 with splitter or o/d) AEC 'box reports that it was a joy to use. Wouldn’t a beefed-up version of that have satisfied the need for a proper 'box, built in-house by a British manufacturer? Or have I missed something and they did that anyway (in which case why is CF whingeing). RobertoThey did Robert, but as has been said before, never let facts stand in the way of a good argument!.
The basic 6-speed o/d gearbox available in the AV760 Mandator was the TET D203 with it’s 1-3/4" input shaft. This, at 615 lb-ft, had a design torque capacity very slightly higher than service torque capacity of the ONLY Fuller Roadranger in production in the UK in 1968, the RT and RTO610. Both were designed for use in service with engines developing up to 600lb-ft torque.
To fit the D203 to the V8 engine required an extended selector housing to allow the change rod to clear the RH cylinder bank. This modified gearbox was designated the D236 and it was fitted to all Mandator V8’s from the start of production until early in 1969.
When the higher output AV800/801 powered V8’s were produced, TET increased the torque capacity of the D236 by beefing up the front end bearings and fitting a 2" input shaft. This gearbox was the D250, and it was fitted to all subsequent V8’s that had the 6-speed gearbox option, including the AV740’s.
Higher capacity 6-speeds were already on the drawing board at TET in 1970, and some of these would go on to be used by Guy in the Big J, AEC/Leyland in the Marathon (behind the L12 engine) and by Scammell in the Routeman, Handyman and Trunker.
By 1976 the last version (to the best of my knowledge) of the old 6-speed was being produced, by this time Eaton had taken over at TET, and this gearbox (still with a 2" input shaft) featured needle roller bearings on the mainshaft gears (as opposed to the bronze bushes of the D236 and D250), higher torque capacity gears and taper roller bearings (as opposed to roller bearings) on the mainshaft and layshaft. This gearbox was the D273 and was a Scammell option right to the end of Routeman production.What a superbly full answer, ‘ERF’; and most heartening too. Many thanks for that!
Robert
And after Eaton had bought the former Thorneycroft plant at Basingstoke the last AEC / Thorneycroft 'boxes had a small Eaton plate tacked onto the casings.
[zb]
anorak:railstaff:
…Makes interesting reading,ive seen the Mack spec sheet on an American forum before,they didn’t believe the Swedish BS either.Quite interesting to see the DS14 and END865 next to each other.The three main differences are,DS14 has lateral bolts into the main housings,the 865 has none.
DS14 has single heads,the 865 has four heads,two either side.
Later 865 had four valve per cylinder,maybe explain the bore increase.
It’s the earlier END864 that has the same bore and stroke as the DS14. The ENDT865 is the later engine, which had different bore/stroke dimensions, although its swept volume was almost identical. The asserion of the Mack enthusiasts is that END864 engines went to Södertälje, and the Scania engineers used them as the basis of their work. That is very believable. Somewhere else on those Mack forums, however, someone says that the DS14 used END864 castings, at some stage. Is that true, or just fanciful extrapolation?
Mack never used the lateral bolts through the main bearing housings,the cooling plates are cast differently into the block,the block face has a slighty different arrangement for the head bolts on the two middle cylinders of each bank.Scania took a great engine and modified it to suit.
Carryfast:
railstaff:
Carryfast:
[zb]
anorak:
Now have a closer look at the specification of that engine, the ENDT865- the new, high torque/low speed V8 had completely different geometry to the old one- it was oversquare! That’s right- to generate more torque, they increased the bore and reduced the stroke! Obviously, the higher torque came from Mack’s clever use of the turbocharger, but it leaves the notion that, had AEC persisted with their turbocharged V8, they would not have been hampered by their base engine geometry, in the pursuit of a torque curve to match their competitors.Seems a bit selective in ignoring the 998 versions.While,unlike Mack,Scania’s development of its V8 has always been a case of concentrating on progressively making very considerable increases in its stroke from the original with just a 3mm increase in bore size to date
Which leaves the question what made Mack drop its interest in the V8 configuration while Scania still sees plenty of life in it ?.
Mack didn’t drop interest in the E9 at all.When Volvo took hold of Mack after the take over of Renault,they shelved Mack power train group and tucked them up with the MP10(D16D Volvo).Seemingly though Ozz hauliers prefer the E9.
Did you actually read the article ?.Hero to hand grenade
virtually overnight when they tried to go for later Scania type outputs obviously using the original Scania 140 stroke let alone the shorter stroke obsolete 865.So what chance did Leyland have of getting any realistic reliable torque output from the AEC’s 114 mm v the 140’s 140 mm.Oh wait that would take an understanding of the importance of the leverage side of the torque equation which obviously doesn’t exist in AEC enthusiast thinking to this day.Unlike Scania’s designers.
This gets better,an expert on Macks v8 after spending ten minutes on you tube,ever seen one in the flesh.Maybe you should look at the production run,because it wasn’t “virtually overnight” they were developed.As for your grenade comment,the odd one suffered head gaskets but that was more an issue of liner protrusion diminishing.Maybe you can tell the forum how many 140,s you have come across running at 110 ton day in,day out?
windrush:
ramone:
This is a question from someone who knows absolutely nothing about gearbox or engine workings ,but wasnt the AEC boxes a slow change, wasnt the old saying you could roll a cig up whilst changing up . I`m thinking that you would lose momentum whilst waiting for the revs to drop or am I missing something … I have my hard hat onNot driven one personally but those drivers of ours who had AEC Marshall’s before the Fodens arrived in the fleet reckoned that whatever gear you had at the bottom of a hill you couldn’t change up again until the top as it was such a slow change? No such problem with a Foden of course…
Pete.
I mentioned this a few years back to my dad and another old driver , they laughed at me and said utter rubbish and they drove the old AECs , it just seems to me that having a slow uphill change would be that last thing you would want. I remember Chris Webb writing on a different thread of having 1 of his dodgy nights on the fiddle getting a lift home in a mandator with a 9 speed fuller and he said the gearbox transformed the performance
ERF:
They did Robert, but as has been said before, never let facts stand in the way of a good argument!.
Oh wait.The ‘facts’ are it was too much trouble to get on the phone to Fuller and ask them for any of their products up to at least the torque capacity of the 12v71.The Fuller was crap anyway compared to a typical weak 6 speed wide ratio Brit box.Might as well also leave the 3 VTG we’ve spent loads of money on developing in the corner of the yard in favour staying with the Mandator dustcart.Which also means that we’ll have to use a dodgy short stroke V8 to fit in it.Meanwhile Scammell has a better product in the form of the 8v71 Crusader that we could use to meet the design requirement.Thereby saving all the pointless wasted development and production budget not to mention warranty costs of the Mandator V8 project.That worked well.
railstaff:
…
Mack never used the lateral bolts through the main bearing housings,the cooling plates are cast differently into the block,the block face has a slighty different arrangement for the head bolts on the two middle cylinders of each bank.Scania took a great engine and modified it to suit.
Can you confirm if the 865 and 1000 engines were based on the original 864 castings, or were the later engines new?
Edit- while we’re on the subject of other V8s, I’m still trying to get my head round the huge difference in numbers produced between the Mack and Scania engines. I looked at the specification of the six cylinder Maxidyne engine (ENDT675), and it is not far behind the contemporary V8 (ENDT865) in torque, so I thought most operators would prefer the six. Unfortunately, I could not find sales figures for the six.
I have put a post on the Scania 140/141/142… thread, for the continuation of this discussion, to relieve AEC fans of the misery of continual digression, although I’m happy just to learn, wherever the information is.
railstaff:
Carryfast:
Did you actually read the article ?.Hero to hand grenadeThis gets better,an expert on Macks v8 after spending ten minutes on you tube,ever seen one in the flesh.Maybe you should look at the production run,because it wasn’t “virtually overnight” they were developed.As for your grenade comment,the odd one suffered head gaskets but that was more an issue of liner protrusion diminishing.Maybe you can tell the forum how many 140,s you have come across running at 110 ton day in,day out?
No the article definitely says hero to hand grenade and obviously not written by me.Which leaves the question why did Scania take a totally opposing development route regarding its V8 v Mack’s.Bearing in mind that,unlike the Mack V8,the Scania is still there putting out a reliable 2,500 lb/ft from around 1,000 rpm not to mention 730 hp.
Carryfast:
Bearing in mind that there were no uk spec 4x2 8v71 Crusaders and that list doesn’t include export market survivors that doesn’t exactly help with any comparison of the relative merits of 8v71 Crusader v AEC V8 as shown in the example I posted.As I’ve said the fact that there were no 4x2 UK spec 32t 8v71 Crusaders seems to be as much conspiracy as the fact that there was no 130x142 V8,13 speed Fuller,3 VTG put on the market before the 140 got there.Surely there can be no doubt that based on the output for engine size and transmission advantages of the 8v71 Crusader that it had to be the better truck and ( would have ) made the V8 Mandator totally pointless had it been offered in the uk spec 4x2 configuration.While the fact that I’ve found a working example of an 8v71 export market Crusader still up to hauling a considerable load but there seems to be no AEC V8 counterparts left there speaks for itself.
Any Mandator V8 still in service now would be 50 years old, so no, I wouldn’t expect there to be any still hauling goods. I know for certain that a couple of New Zealand V8s worked until the early 1990s, owned by a man whose surname is Lowe, from a remote part of South Island. If you want to speculate that an 8v71 DD powered 4x2 Crusader would have rendered the Mandator V8 “pointless”, well, the instruction from Leyland Head Office went to AEC at Southall to develop a V8 engine and tractor unit, not to Scammell at Watford to use an established V8 engine in the Crusader range.
And we’ve had this debate before. Much to your apparent disbelief AEC did have a very loyal and supportive customer base, so IF the Mandator V8 had been a viable product then it would still have been bought by existing AEC customers irrespective if there had been a competing V8 engined 4x2 Crusader or not. AEC registered 3,000 to 3,500 chassis annually in the open market in the UK; Scammell’s open market registrations of “normal” tractor units and eight wheelers in the UK were 800 to 1000. Customer loyalty is a concept that you repeatedly ignore.
gingerfold:
Carryfast:
Bearing in mind that there were no uk spec 4x2 8v71 Crusaders and that list doesn’t include export market survivors that doesn’t exactly help with any comparison of the relative merits of 8v71 Crusader v AEC V8 as shown in the example I posted.As I’ve said the fact that there were no 4x2 UK spec 32t 8v71 Crusaders seems to be as much conspiracy as the fact that there was no 130x142 V8,13 speed Fuller,3 VTG put on the market before the 140 got there.Surely there can be no doubt that based on the output for engine size and transmission advantages of the 8v71 Crusader that it had to be the better truck and ( would have ) made the V8 Mandator totally pointless had it been offered in the uk spec 4x2 configuration.While the fact that I’ve found a working example of an 8v71 export market Crusader still up to hauling a considerable load but there seems to be no AEC V8 counterparts left there speaks for itself.
Any Mandator V8 still in service now would be 50 years old, so no, I wouldn’t expect there to be any still hauling goods. I know for certain that a couple of New Zealand V8s worked until the early 1990s, owned by a man whose surname is Lowe, from a remote part of South Island. If you want to speculate that an 8v71 DD powered 4x2 Crusader would have rendered the Mandator V8 “pointless”, well, the instruction from Leyland Head Office went to AEC at Southall to develop a V8 engine and tractor unit, not to Scammell at Watford to use an established V8 engine in the Crusader range.
And we’ve had this debate before. Much to your apparent disbelief AEC did have a very loyal and supportive customer base, so IF the Mandator V8 had been a viable product then it would still have been bought by existing AEC customers irrespective if there had been a competing V8 engined 4x2 Crusader or not. AEC registered 3,000 to 3,500 chassis annually in the open market in the UK; Scammell’s open market registrations of “normal” tractor units and eight wheelers in the UK were 800 to 1000. Customer loyalty is a concept that you repeatedly ignore.
I think you are wrong there Graham, he ignores every concept that doesnt fit in with his warped way of thinking. As ive read this thread it seems quite apparent that Southall were instructed to build a compact V8 with dimensions to fit under the newly designed and built cab . Obviously when big brother tells you to do something you have little choice. They did exactly what they were told but the engine was put into production far too early. If Leyland had stepped back and taken notice of what was being said at Southall there could have been a different outcome . Using a certain posters use of hindsight did we really need a compact V8 .Leyland went on to instruct AEC to develop the TL12 and put it under a raised cab so maybe they could have saved money on the V8 in the first place and brought the Marathon out in `68 … hindsight hey 
ramone:
…As i`ve read this thread it seems quite apparent that Southall were instructed to build a compact V8 with dimensions to fit under the newly designed and built cab . Obviously when big brother tells you to do something you have little choice. They did exactly what they were told but the engine was put into production far too early. If Leyland had stepped back and taken notice of what was being said at Southall there could have been a different outcome …
An engineer in the MD’s chair will engineer the firm’s future. A salesman…
ramone:
This is a question from someone who knows absolutely nothing about gearbox or engine workings ,but wasnt the AEC boxes a slow change, wasnt the old saying you could roll a cig up whilst changing up . I`m thinking that you would lose momentum whilst waiting for the revs to drop or am I missing something … I have my hard hat on
It is all to do with the closeness of the ratios, the number of them and whether there is a cluch brake or not. Even with a slow changing box it is possible to ‘■■■■■■’ the next higher gear.
AEC Marshall AV 505 D197 'box slow change:
youtube.com/watch?v=Z3n7mFjCKU0
Scammell Routemann Leyland O600 AEC/TET D203 Box
Slow change
youtube.com/watch?v=FVE8s5aXkQs
1957 AEC Mandator AEC 5 speed? gearbox with a clutch brake fast change
youtube.com/watch?v=U0vmA4NYoTM&t=143s
AEC Mammoth Major AV 760 Fuller box and clutch brake
gingerfold:
And we’ve had this debate before. Much to your apparent disbelief AEC did have a very loyal and supportive customer base, so IF the Mandator V8 had been a viable product then it would still have been bought by existing AEC customers irrespective if there had been a competing V8 engined 4x2 Crusader or not. AEC registered 3,000 to 3,500 chassis annually in the open market in the UK; Scammell’s open market registrations of “normal” tractor units and eight wheelers in the UK were 800 to 1000. Customer loyalty is a concept that you repeatedly ignore.
Oh wait.Haven’t we also established elsewhere that one of the reasons for the collapse of the UK truck manufacturing industry was the issue of manufacturers taking customer loyalty for granted in the form of dodgy under developed under specced products which weren’t up to the job.The V8 Mandator and 500 powered heaps predictably being two of the worse culprits.While ironically we’re obviously seeing the Leyland Group inter marque rivalries and loyalties,standing in the way of objective engineering decisions and rationalisation,which are also often referred to in helping to bring down Leyland Group,happening here within this discussion.
While I’m obviously looking at it from my old instilled use whatever is best for the job attitude.Which,from experience,also applied at Scammell just as it did in our case.Which in this case translates as either use the 3 VGT using a decent V8 design and Fuller box or the 8v71 Crusader to meet the spec.Bearing in mind that the latter option would have given AEC the resources to be put where they were needed in developing a decent 690 6 cylinder replacement rather than the lame duck 62 lb/ft per litre TL12.So there we have it a compromised 32 tonner with a gutless grenade for an engine and a dustcart cab,which predictably cost Leyland a fortune in warranty claims costs,all because of blind loyalty to a badge and idiotic inter marque rivalry between AEC and Scammell.Scammell being the innocent party and eventual victim in all that. 
ramone:
I think you are wrong there Graham, he ignores every concept that doesnt fit in with his warped way of thinking. As ive read this thread it seems quite apparent that Southall were instructed to build a compact V8 with dimensions to fit under the newly designed and built cab . Obviously when big brother tells you to do something you have little choice. They did exactly what they were told but the engine was put into production far too early. If Leyland had stepped back and taken notice of what was being said at Southall there could have been a different outcome . Using a certain posters use of hindsight did we really need a compact V8 .Leyland went on to instruct AEC to develop the TL12 and put it under a raised cab so maybe they could have saved money on the V8 in the first place and brought the Marathon out in `68 … hindsight hey
It being clear that big brother in this case was Fogg you know the same Fogg who also inflicted the 500 on the Group.So how difficult could it have been for any decent designer to say no we either develop the 3 VTG with a decent V8 or use the 8v71 Scammell to meet the requirement or I resign because I don’t want to be associated with the thing.Oh wait according to Fryers AEC’s designers were both horrified and delighted by the instruction at the same time.While obviously according to CM Roberts was just as enthusiastic about the resulting torqueless short stroke screamer as Fogg.
While it’s obvious that whatever Stokes felt about it he was out voted by his whole engineering department headed by Fogg and a load of other assorted AEC fan boys anyway so might as well go along with it.The result being that those fan boys even now to this day use Stokes as the scapegoat when the thing all too predictably didn’t work.
[zb]
anorak:ramone:
…As i`ve read this thread it seems quite apparent that Southall were instructed to build a compact V8 with dimensions to fit under the newly designed and built cab . Obviously when big brother tells you to do something you have little choice. They did exactly what they were told but the engine was put into production far too early. If Leyland had stepped back and taken notice of what was being said at Southall there could have been a different outcome …An engineer in the MD’s chair will engineer the firm’s future. A salesman…
Isn’t this the same ‘salesman’ that went through an engineering apprenticeship at Leyland and who was then given a leadership role over REME field engineering operations v his German counterparts in time of war ?.While wasn’t it Fogg and Roberts who were the two most vocal and enthusiastic supporters of the AEC V8 project ?.
Carryfast:
railstaff:
Carryfast:
Did you actually read the article ?.Hero to hand grenadeThis gets better,an expert on Macks v8 after spending ten minutes on you tube,ever seen one in the flesh.Maybe you should look at the production run,because it wasn’t “virtually overnight” they were developed.As for your grenade comment,the odd one suffered head gaskets but that was more an issue of liner protrusion diminishing.Maybe you can tell the forum how many 140,s you have come across running at 110 ton day in,day out?
No the article definitely says hero to hand grenade and obviously not written by me.Which leaves the question why did Scania take a totally opposing development route regarding its V8 v Mack’s.Bearing in mind that,unlike the Mack V8,the Scania is still there putting out a reliable 2,500 lb/ft from around 1,000 rpm not to mention 730 hp.
And what opposing route would that be then?
Let us not forget what was Europes most powerful truck at one time.
The Renault AE560 Magnum with the Mack E9.A four valve development of the END 684.Dont remember that being a grenade.
We must remember that the DC16 was a completely new engine in 2000, while the E9 was a development of the original 1962 END864 (I think. Don’t trust the things I have read 100% ). When you add into the equation that the design of the DS14 was based on the same platform (I still think this needs some form of verification. I don’t think the Scania Museum is the best place to ask, though ), the Mack engineers deserve a whole heap of credit, IMO. Along with the Maxidyne concept, their contribution to diesel engine development in the 1960s makes all others pale into insignificance, IMO.
I still can’t work out why Mack’s sales were so low compared to Scania’s, at least in the realm of V8s (Again, we must check these sources). Maybe they needed a decent salesman at the helm.
[zb]
anorak:railstaff:
…
Mack never used the lateral bolts through the main bearing housings,the cooling plates are cast differently into the block,the block face has a slighty different arrangement for the head bolts on the two middle cylinders of each bank.Scania took a great engine and modified it to suit.Can you confirm if the 865 and 1000 engines were based on the original 864 castings, or were the later engines new?
Edit- while we’re on the subject of other V8s, I’m still trying to get my head round the huge difference in numbers produced between the Mack and Scania engines. I looked at the specification of the six cylinder Maxidyne engine (ENDT675), and it is not far behind the contemporary V8 (ENDT865) in torque, so I thought most operators would prefer the six. Unfortunately, I could not find sales figures for the six.
I have put a post on the Scania 140/141/142… thread, for the continuation of this discussion, to relieve AEC fans of the misery of continual digression, although I’m happy just to learn, wherever the information is.
The E9(998ci) was based on the original 864 block but with 4 valve per cylinder heads,still two heads per bank.It was rated at 600hp,over 800hp in Marine.
I don’t think the sales figures are correct.New Zealand and oz were Mack stomping ground.Plus all of USA.Like to see how many E9 Renault took.
