AEC V8

[gingerfold]

The 3VTG Concept truck. Yes, it most certainly was fitted with the twin-turbo V8 for extensive road testing. In fact there were two of them, both 6X4, one with a normally aspirated V8, the other with the turbo-charged engine, which was given special dispensation to run at 44 tons gross with a payload of 31.5 tons.

They were built, cabs and all by AEC’s Experimental department workshops.

And there was a 4x2 version as well…but you will have to visit the Marathon thread to see that and learn what it was for.

[carryfast]

gingerfold:

Carryfast:
I don’t think inconvenient questions like how did a ( correct ) 300-350 hp V8 design requirement suddenly get downgraded eventually to the
point of a 280 6 cylinder one ?.

Bob Fryars answered that question, it was because of excessive noise emissions and the recommendation nearly cost him his job. The excessive noise has always been cited as a reason for withdrawing the V8, something I had personally not fully understood until the explanation from Bob. There is also a lot about engine noise research carried out at Southampton University which is far too technical for me so I’ve not quoted it.

How did both Scammell and much more importantly Scania in this case both manage chassis designs to meet that spec whereas AEC couldn’t.Bearing in mind that they were all working without modern design aids at the same point in time ?.

Maybe AEC approached the problem from the wrong direction? In other words get the engine and then design the chassis and cab around it. Rather than fit a different engine “shape” into an existing chassis and cab that was already known to be unsuitable for the bigger in-line engines of AEC and Leyland. The Ergomatic should have been limited to AV505 and O.400 powered models, (Again with hindsight from a distance of 50 years.)

Together with the obvious observation,that AEC’s so called ‘design limitations’ were actually all the result of a self inflicted cascading load of errors of its own making in trying to make the wrong engine to fit in the wrong truck,unlike Scania.Which instead of trying to fix they instead chose to work around with predictable results.Is all a bit more than just ‘nit picking’.

Nor does the ongoing inconvenient question,of the obvious contradiction and inconsistency in Fryers’ story,regarding the reference to both horror and delight,both clearly being meant in the sense of in the day and at the time,not retrospective hindsight,amount to disrespect.As opposed to him naively making excuses for the failings of others like Roberts and Fogg.IE he actually said ''With the corporate instruction to proceed with a new engine ( silly short stroke V8 ) and chassis carrying a much better walk through version of the Ergo cab all of us at AEC WERE delighted.Don’t you think that it’s strange how Scania didn’t see it the same way in the case of the 140.In addition to the Scania V8 proving that Fryer’s reference to a decent stroke automatically meaning an unmanageable impossible height was total bs.Yes only unmanageable if it’s put in something designed to be a dustcart or local shop delivery design not a max weight 300-350 hp long hauler.

Horror and delight. Again, I have quoted reactions that have been taken out of context, and I accept responsibility for that because I edited the original post as I didn’t want to make it too lengthy. The “horror” was because they knew what they were up against. The “delight” was because AEC had actually been given a new project, the first one since the merger with Leyland except for the A505 / A760 engines, which had been sanctioned by Stanley Markland, and without the approval at the time of Donald Stokes because, at that stage, Markland and Stokes were of equal status within the Leyland hierarchy. Leyland had a ruthless approach to its acquired companies; all the Albion senior management were sacked when Leyland took over and the same policy was enacted at Standard Triumph. That didn’t happen to the same extent with AEC but the V8 project was a guarantee of work for the foreseeable future.

Finally, the height of the engine. Nowhere has it been said that AEC didn’t originally consider a longer stroke tall V8 engine. The original raison d’etre for the V8 was to fit under Guy cabs and the BMC FJ cab IF that AEC and BMC merger had gone ahead. Again, AEC were having to approach the design from the wrong direction and when that merger didn’t happen the engine design was shelved. When it was resurrected then if the Leyland board had said they could have had a new cab, or a Marathon style raised Ergomatic cab then AEC might have built a long stroke tall V8, after all they had sussed out that option back in 1961 when they got hold of the ■■■■■■■ patents. If that scenario had happened then this thread wouldn’t exist. But no doubt we’d be arguing about something else.

The contradiction between horror v delight and exactly what that referred to is contained within Fryers stated own specific words ( delight at the idea of putting ‘the’ engine under the walk through Ergo cab that obviously being the Mandator ).As opposed to telling CM ( he was supposedly horrified when told it was going in the Mandator obviously Fogg and Roberts driving that agenda ) nothing to do with you or any context you’ve drawn.Just as the contradiction between them supposedly not having a clue as to what the engine was going to be used for ( again his words reported in the CM article nothing to do with you ).As opposed to its obvious job always known as being first and foremost a doomed to failure attempt to meet the supposed bs,now you see it now you don’t,300-350 hp design target within the constraints of a truck best suited to a dustcart.Not the premium truck in the league of the Scania 140 which they needed.

As for what might have been.Ironically,like the Griffon Spit,something along the lines of the 3 VTG not the Marathon combined with a 690 based 140 V8 competitor would have got the job done and we would probably be talking about the miracle of how AEC defeated Scania in the UK market based on making the right choices in 1964-68.Bearing in mind the 3VTG actually existed at that point.

Which leaves the question of exactly what ‘relationship’ might have existed between AEC and Scania regarding a possible merger.Could it have been that Scania actually held sufficient financial interest in AEC to block/scupper the Leyland deal and transition ‘if’ AEC hadn’t given a behind closed doors undertaking not to tread on Scania’s toes ?.Which would explain all the diversionary unbelievable bs,concerning the impossible to understand commercially suicidal design ideas going on within Leyland Group at this time.IE like the Marathon and T45 all being a sell out to help the foreign competition made to look good for the consumption of the public and Leyland’s naive doomed workforce.

[carryfast]

gingerfold:
The 3VTG Concept truck. Yes, it most certainly was fitted with the twin-turbo V8 for extensive road testing. In fact there were two of them, both 6X4, one with a normally aspirated V8, the other with the turbo-charged engine, which was given special dispensation to run at 44 tons gross with a payload of 31.5 tons.

They were built, cabs and all by AEC’s Experimental department workshops.

And there was a 4x2 version as well…but you will have to visit the Marathon thread to see that and learn what it was for.

Would it be correct to think that the 3 VTG had the room for a larger longer/wider/taller V8 design than the AEC V8 to fit ?.IE wider front track/wider spaced chassis rails/higher set cab floor height and wider engine hump ?.

[railstaff]

Carryfast:

railstaff:
I stand corrected,looking at the ariel shot,the Mandator used a tapered frame and quite a sharp one at that.Effectively reducing steering lock.Was that just for the 740 engine model?

Ironically none of that taper seeming to be where it was most needed further back instead of where it closed in towards the rear of engine.

It would have been interesting to see how the 3 VTG,Crusader and the Scania 140 all compared with the Mandator.

It looks like AEC’s designers were working with an impossible combination of narrow track dimensions meaning narrow set chassis rails which then couldn’t be compensated for by any amount of taper.Realistically it was a borderline 32 tonner if at all and Leyland might just as well have left that sector well alone to the Crusader and the Big J and concentrated on pitching the Mandator at the rigid and medium duty tractor unit market sector but which it obviously chose instead to lumber with the 500 engined range just to make matters even worse.

Clearly the problem with folding the frame further backwards as you describe and were AEC went wrong in your opinion is, it would limit the use of the frame.For example a 6 x 4 might struggle as the first drive wheels would not clear the frame.

As for engine height we are discussing 90 degree vee engines,not vertical inlines.

[carryfast]

railstaff:

Carryfast:

railstaff:
I stand corrected,looking at the ariel shot,the Mandator used a tapered frame and quite a sharp one at that.Effectively reducing steering lock.Was that just for the 740 engine model?

Ironically none of that taper seeming to be where it was most needed further back instead of where it closed in towards the rear of engine.

It would have been interesting to see how the 3 VTG,Crusader and the Scania 140 all compared with the Mandator.

It looks like AEC’s designers were working with an impossible combination of narrow track dimensions meaning narrow set chassis rails which then couldn’t be compensated for by any amount of taper.Realistically it was a borderline 32 tonner if at all and Leyland might just as well have left that sector well alone to the Crusader and the Big J and concentrated on pitching the Mandator at the rigid and medium duty tractor unit market sector but which it obviously chose instead to lumber with the 500 engined range just to make matters even worse.

Clearly the problem with folding the frame further backwards as you describe and were AEC went wrong in your opinion is, it would limit the use of the frame.For example a 6 x 4 might struggle as the first drive wheels would not clear the frame.

As for engine height we are discussing 90 degree vee engines,not vertical inlines.

Firstly I was only suggesting that as a possibile solution while it seems to be the whole lot that’s wrong starting with the rear and then front track not being enough leading to too narrow chassis rail separation resulting in compromised engine space between the chassis rails.As for 6x4 that would obviously have meant a longer chassis than the 4 x 2 shown anyway.Whatever the cause or the solution much of the problem seems to be the resulting pinch point between the chassis rails v the engine at around just forward of where the header tank is situated.Which is why I said it would have been interesting to see the equivalent 8v71 Crusader and Scania 140 chassis rail seperation and clearance around their respective engine locations and how they obtained it.

As for engine height.The point was Fryers also clearly stated that a longer stroke V8 would have created too many height issues.When firstly the respective heights of the Scania v the 8v71 show that overall height isn’t directly proportional to the stroke length of a V engine.While the AEC V8’s stroke was undoubtedly compromised in that regard because of the excessive restrictions imposed by its chassis and cab design.With them then trying to dress that up as an advantage.

Realistically the whole subject revolves around the question of how and why did the AEC V8 turn out to be such an absolute predictable abortion v the Scania 140 and in thereby meeting its 300 + hp design target and was that deliberate.Especially if it can be shown that the 3 VTG would have provided the required engine location space to make a serious 140 competitor.

[carryfast]

Carryfast:
While I only asked the question which would obviously need the comparative track and chassis rail seperation widths around the engine of the 140 and the Crusader at least,to answer it.

Edit to add.Scania at least seemed to go for a big vertical chamfer of its rails.Which allowed much of the engine to sit above them then set the cab well above the chassis to allow more clearance.Although it’s difficult to gauge any extra rail seperation width provision from that but probably some in addition.

youtube.com/watch?v=IEdvbUwTcZU

youtube.com/watch?v=9nbz8yx82oc 0.51

Which leaves the question why wasn’t the 3VTG project all about making a direct competitor along those lines and taken forward instead of wasting resources on the Mandator and the Marathon ?.

[railstaff]

Carryfast:

railstaff:

Carryfast:

railstaff:
I stand corrected,looking at the ariel shot,the Mandator used a tapered frame and quite a sharp one at that.Effectively reducing steering lock.Was that just for the 740 engine model?

Ironically none of that taper seeming to be where it was most needed further back instead of where it closed in towards the rear of engine.

It would have been interesting to see how the 3 VTG,Crusader and the Scania 140 all compared with the Mandator.

It looks like AEC’s designers were working with an impossible combination of narrow track dimensions meaning narrow set chassis rails which then couldn’t be compensated for by any amount of taper.Realistically it was a borderline 32 tonner if at all and Leyland might just as well have left that sector well alone to the Crusader and the Big J and concentrated on pitching the Mandator at the rigid and medium duty tractor unit market sector but which it obviously chose instead to lumber with the 500 engined range just to make matters even worse.

Clearly the problem with folding the frame further backwards as you describe and were AEC went wrong in your opinion is, it would limit the use of the frame.For example a 6 x 4 might struggle as the first drive wheels would not clear the fra

As for engine height we are discussing 90 degree vee engines,not vertical inlines.

Firstly I was only suggesting that as a possibile solution while it seems to be the whole lot that’s wrong starting with the rear and then front track not being enough leading to too narrow chassis rail separation resulting in compromised engine space between the chassis rails.As for 6x4 that would obviously have meant a longer chassis than the 4 x 2 shown anyway.Whatever the cause or the solution much of the problem seems to be the resulting pinch point between the chassis rails v the engine at around just forward of where the header tank is situated.Which is why I said it would have been interesting to see the equivalent 8v71 Crusader and Scania 140 chassis rail seperation and clearance around their respective engine locations and how they obtained it.

As for engine height.The point was Fryers also clearly stated that a longer stroke V8 would have created too many height issues.When firstly the respective heights of the Scania v the 8v71 show that overall height isn’t directly proportional to the stroke length of a V engine.While the AEC V8’s stroke was undoubtedly compromised in that regard because of the excessive restrictions imposed by its chassis and cab design.With them then trying to dress that up as an advantage.

Realistically the whole subject revolves around the question of how and why did the AEC V8 turn out to be such an absolute predictable abortion v the Scania 140 and in thereby meeting its 300 + hp design target and was that deliberate.Especially if it can be shown that the 3 VTG would have provided the required engine location space to make a serious 140 competitor.

No its not obvious because even a 6 x 4 tractive unit had to be built within a certain lenth,sweeping the frame further rearwards would interfere with fitments.Another example of this is trying to attach spring hangers on the swept area of the frame is awkward.

[erf]

gingerfold:
…Bob Fryars is in his 90s yet he has taken the trouble to give a comprehensive and detailed record of events, both internal and external, that shaped the decision making processes of over 50 years ago, a very, very different world we live and work in now. He has disclosed information that none on here knew of before. For that alone he deserves our thanks and I would politely request CF, for once in his posting life, to give the man some respect instead of nit-picking to the nth degree about trivialities.

Sadly, I think you have your answer gingerfold

Carryfast:
…it seems to be the whole lot that’s wrong starting with the rear and then front track not being enough leading to too narrow chassis rail separation resulting in compromised engine space between the chassis rails.As for 6x4 that would obviously have meant a longer chassis than the 4 x 2 shown anyway.Whatever the cause or the solution much of the problem seems to be the resulting pinch point between the chassis rails v the engine at around just forward of where the header tank is situated.Which is why I said it would have been interesting to see the equivalent 8v71 Crusader and Scania 140 chassis rail seperation and clearance around their respective engine locations and how they obtained it.

Realistically the whole subject revolves around the question of how and why did the AEC V8 turn out to be such an absolute predictable abortion v the Scania 140 and in thereby meeting its 300 + hp design target and was that deliberate.Especially if it can be shown that the 3 VTG would have provided the required engine location space to make a serious 140 competitor…

More utter nonsense.
I really don’t understand how you have managed to completely invent this issue of AEC V8 chassis rail separation into which you put so much importance. It exists only in your mind.
Against my better judgement, once again, I will try to educate you one last time.

Nowehere on this thread is there any mention of insufficient space between the chassis rails (except from you) to fit ANY engine. If you go back and READ THE POSTS PROPERLY you will see that I said the Detroit V6 was often used to replace the AEC engine in service in New Zealand. This required sections of the high datum cab floor to be cut out to clear the Detroit engine. It was impossible, or prohibitively difficult, to fit the Detroit V8 - obviously due to cab clearance and accommodating the radiator, nothing whatsoever to with this imaginary chassis rail clearence issue you have invented.

Under every lorry chassis (well…in the real world anyway) there are things called ‘axles’. On the ends of these ‘axles’ are big round things with rubber wrapped around them called ‘wheels’.
Between these ‘wheels’ is the ‘chassis’. The maximum chassis rail spacing is governed by allowing enough clearance to allow the ‘wheels’ to turn!.

You say you would be interested in a chassis rail separation comparison between the AEC V8, Crusader V8 and Scania 140 V8. They are all almost identical, as they would be. If you want to satisfy yourself, and it will end this ridiculous nonsense, I will even extend an invitation to you to come armed with your tape measure and compare them all for yourself!!. They are not all my vehicles, but all are accessible within a 15 mile radius.
Over to you to move the goalposts. Again.

I find it a great shame that really good and informed input on this thread is just wasted. Lost amid the constant and relentless flow of waffle and nonsense.

[gingerfold]

At the end of the day AEC did what they were instructed to do by the Leyland Group Board of Directors and there is no getting away from that fact, irrespective of what the final result was. Leyland had suffered with the Tattersall engine and they had actually sanctioned the building of a new engine plant to produce 300 Tattersall engines weekly before one of these engines had even been tested. So with the very firm directive from the Directors about what the V8 was to be, and that it had to fit modified existing chassis and cab layouts, the design and development team had to follow the directive from head office to the letter. As I have written previously all that AEC had in late 1964 was a short stroke in-line experimental engine and a set of plans. If the instruction from above had been to start with a clean sheet design for engine, chassis, and cab then who knows what the final outcome might have been. The history of commercial vehicle design is littered with ifs, buts, and maybes.

As for Scania and AEC, then in the early 1960s the ACV group was the bigger company of the two and had a much larger world wide market. ACV had judged that the Commonwealth countries, where they had always enjoyed high sales figures, would become a declining market. They had identified the potential of the European market for future growth, that is why they considered Scania. The late Jim Slater was the AEC manager directing export strategy. Whatever the future held for him, Jim Slater was no mug.

[ramone]

Do you know what happened to the concept vehicles Graham, did they end up being broken up?

[cav551]

So now we are on chassis rails etc not being to the master designer’s specification. We do have to bow to the opinion of the special one since he holds a Royal Warrant for supply of " Comfy Grip" bog chain handles.

Distance between chassis rails mid chassis:

AEC Mandator V8 2’10"
Scammell Crusader 2’ 10"
Scania 111 not given in CM

Height of cab:

AEC Mandator V8 8’- 1/2"
Scammell Crusader 9’ 7- 1/2"
Scania 111 9’ 8-1/2"

Front track:

AEC Mandator V8 6’ 3.2"
Scammell Crusader 6’ 7.7"
Scania 111 not given in CM

Rear Track:

AEC Mandator V8 5’ 11-1/2"
Scammell Crusader 5’ 11.4"
Scania 111 not given in CM

AEC fitted several width front axles from 6’ 2+" to 6’ 8+" according to chassis application.
From memory only, which may be incorrect, the Mercury and Marshall chassis used a wider track front axle, plated at 6 tons while the 691/760 powered Mandator chassis used a narrow track front axle plated at 5-1/2tons and did not have a power steering ram.

The physical dimensions of the AEC V8 are I think mentioned in a previous post or a link from one. The ones for the V8 Scania, The ■■■■■■■ VINE ( I think given in the law suit) and the Detroit V8 are no doubt available. I cannot be bothered to spend time looking them up since without reference to numerous other chassis dimensions they will be meaningless.

[coomsey]

Most of this topic goes over my head but still very interesting. But don’t you think it could be time to rename the thread. I’m thinking The AEC V8 Perseverance Society springs to mind. Cheers Paul

[gingerfold]

ramone:
Do you know what happened to the concept vehicles Graham, did they end up being broken up?

I believe that they were broken up Ramone. Incidentally, Robert Smith one of the test drivers, called the 6x4 his “44 tons armchair”, apparently it was very comfortable.

[carryfast]

railstaff:

Carryfast:
Realistically the whole subject revolves around the question of how and why did the AEC V8 turn out to be such an absolute predictable abortion v the Scania 140 and in thereby meeting its 300 + hp design target and was that deliberate.Especially if it can be shown that the 3 VTG would have provided the required engine location space to make a serious 140 competitor.

No its not obvious because even a 6 x 4 tractive unit had to be built within a certain lenth,sweeping the frame further rearwards would interfere with fitments.Another example of this is trying to attach spring hangers on the swept area of the frame is awkward.

It’s clear that a 6 x 4 chassis was going to have to be a lot longer than the 4 x 2 example shown regardless.Nor would it have been impossible to have started the taper a bit further back in either case without affecting the axle mounting points.

While it’s obvious that the Ergo dustcart was never going to meet the design aim of a Scania 140 competitor anyway which as I said leaves the question of the 3 VTG.

[carryfast]

ERF:

Carryfast:
…it seems to be the whole lot that’s wrong starting with the rear and then front track not being enough leading to too narrow chassis rail separation resulting in compromised engine space between the chassis rails.As for 6x4 that would obviously have meant a longer chassis than the 4 x 2 shown anyway.Whatever the cause or the solution much of the problem seems to be the resulting pinch point between the chassis rails v the engine at around just forward of where the header tank is situated.Which is why I said it would have been interesting to see the equivalent 8v71 Crusader and Scania 140 chassis rail seperation and clearance around their respective engine locations and how they obtained it.

Realistically the whole subject revolves around the question of how and why did the AEC V8 turn out to be such an absolute predictable abortion v the Scania 140 and in thereby meeting its 300 + hp design target and was that deliberate.Especially if it can be shown that the 3 VTG would have provided the required engine location space to make a serious 140 competitor…

More utter nonsense.
I really don’t understand how you have managed to completely invent this issue of AEC V8 chassis rail separation into which you put so much importance. It exists only in your mind.
Against my better judgement, once again, I will try to educate you one last time.

Nowehere on this thread is there any mention of insufficient space between the chassis rails (except from you) to fit ANY engine. If you go back and READ THE POSTS PROPERLY you will see that I said the Detroit V6 was often used to replace the AEC engine in service in New Zealand. This required sections of the high datum cab floor to be cut out to clear the Detroit engine. It was impossible, or prohibitively difficult, to fit the Detroit V8 - obviously due to cab clearance and accommodating the radiator, nothing whatsoever to with this imaginary chassis rail clearence issue you have invented.

Under every lorry chassis (well…in the real world anyway) there are things called ‘axles’. On the ends of these ‘axles’ are big round things with rubber wrapped around them called ‘wheels’.
Between these ‘wheels’ is the ‘chassis’. The maximum chassis rail spacing is governed by allowing enough clearance to allow the ‘wheels’ to turn!.

You say you would be interested in a chassis rail separation comparison between the AEC V8, Crusader V8 and Scania 140 V8. They are all almost identical, as they would be. If you want to satisfy yourself, and it will end this ridiculous nonsense, I will even extend an invitation to you to come armed with your tape measure and compare them all for yourself!!. They are not all my vehicles, but all are accessible within a 15 mile radius.
Over to you to move the goalposts. Again.

I find it a great shame that really good and informed input on this thread is just wasted. Lost amid the constant and relentless flow of waffle and nonsense.

Yes we know there are big round things called wheels attached to the ends of the axles which will determine the width available for the chassis and therefore engine as part of that.That’s why I referred to the ‘track’ measurement.Looking at the Scania it appears that it’s front track at least is wider than that of the Ergo.While the engine area of the chassis and the engine and cab mounting heights were all made to suit the correct engine design for the job regardless.It’s also clear that the Scania’s designers approached the design aim of a 300 hp + V8 powered truck with a totally different premise to that of AEC from the start.IE let’s do it right.As opposed to let’s fit a compromised motor,which doesn’t stand the slightest chance of meeting its design aims,so as to fit in the available space of a truck ( Ergo ) designed to ideally meet the requirements of the dustcart and brewery/shop local delivery market sectors.

[ramone]

gingerfold:

ramone:
Do you know what happened to the concept vehicles Graham, did they end up being broken up?

I believe that they were broken up Ramone. Incidentally, Robert Smith one of the test drivers, called the 6x4 his “44 tons armchair”, apparently it was very comfortable.

I have posted on the Marathon thread regarding this , there was an article in the AEC Gazette a few years back regarding these vehicles running up and down the M4 but i cant remember if it was the V8 or the TL12. I think it was in a couple of Gazettes

[erf]

As is so often the case, the real world throws up facts which completely contradict Carryfast’s nonsensical waffling.

cav551:
Distance between chassis rails mid chassis:

AEC Mandator V8 2’10"
Scammell Crusader 2’ 10"
Scania (LB140 - 2’ 6.315")

Front track:

AEC Mandator V8 6’ 3.2" Edit - it’s actually 6’ 8.1875" - cav551 quoted a mistake in the CM article - they meant 6’ 8.2" but it printed with an error, 3 instead of 8.
Scammell Crusader 6’ 7.7"
Scania (LB140 - 6’ 8.83")

Rear Track:

AEC Mandator V8 5’ 11-1/2"
Scammell Crusader 5’ 11.4"
Scania (LB140 - 5’ 10.875)

So, despite a one inch wider front track, the Scania actually has a NARROWER chassis than either the AEC V8, or the Crusader, the latter being Identical from mid chassis to rear. I recalled 770mm as the Scania rear frame width measurement from years ago, but a quick rifle through the 1970’s chassis drawing sheets has just confirmed it.

In fact, in the crucial area of the engine bay (…only in CF’s eyes), the AEC chassis is actually 0.52" WIDER than the LB140. I can already hear those goalposts shifting…

Meanwhile, here are some AEC V8 vs Scania V8 chassis comparison pics.

In reality it is amazing how very similar the two designs are, but then there are only so many ways you can design a good V8 lorry chassis…

[carryfast]

ERF:
As is so often the case, the real world throws up facts which completely contradict Carryfast’s nonsensical waffling.

cav551:
Distance between chassis rails mid chassis:

AEC Mandator V8 2’10"
Scammell Crusader 2’ 10"
Scania (LB140 - 2’ 6.315")

Front track:

AEC Mandator V8 6’ 3.2"
Scammell Crusader 6’ 7.7"
Scania (LB140 - 6’ 8.83")

Rear Track:

AEC Mandator V8 5’ 11-1/2"
Scammell Crusader 5’ 11.4"
Scania (LB140 - 5’ 10.875)

So, despite a one inch wider front track, the Scania actually has a NARROWER chassis than either the AEC V8, or the Crusader, the latter being Identical from mid chassis to rear. I recalled 770mm as the Scania rear frame width measurement from years ago, but a quick rifle through the 1970’s chassis drawing sheets has just confirmed it.

In fact, in the crucial area of the engine bay (…only in CF’s eyes), the AEC chassis is actually 0.52" WIDER than the LB140. I can already hear those goalposts shifting…

Meanwhile, here are some AEC V8 vs Scania V8 chassis comparison pics.

In reality it is amazing how very similar the two designs are, but then there are only so many ways you can design a good V8 lorry chassis…

3
2
1
0

Fair enough.

Which leaves the question what was stopping the 3VTG being the relevant design to take forward and exactly what was stopping them using a decent 690 based 130 x 142 V8 to meet the design brief of a 300 hp + V8 powered vehicle and obvious Scania 140 competitor as part of that.Unlike the Mandator.While a front track of 6’ 8.83’’ isn’t exactly ‘similar’ to a front track of 6’ 3.2’'.That’s almost half a foot wider track not bleedin 1 inch.Nor is the distance available mid to rear chassis exactly helpful in determining how much we’ve got to sit the engine between unless we’re going for a mid engined truck.In which case I’ll take your given engine area available width with pinch of salt thanks.Seems to be you who’s desperately moving the goal posts.With it being obvious that the Scania motor won’t sit in the chassis space shown in the photo provided previously which showed only just enough space for the smaller AEC moped motor.In large part because of the obvious pinch point I referred to.Let alone the narrower and lower mounted AEC dustcart cab then dropped on top of it.

While actually just digging a bigger hole regarding the questions of just what were AEC playing at here v Scania.Especially regarding the choice of the Manadator v 3 VTG with it being my guess that the 3 VTG just ‘might’ ‘possibly’ have given AEC the type of measurements they needed to sort out the Scania ?.Although I obviously don’t have the luxury of all the relevant details to hand but wouldn’t be at all surprised if AEC had made a cab over Pete knock off that still didn’t have enough room to fit a decent V8 motor in it.While if by some miracle they had it seems ‘strange’ why they then went for the Mandator instead.

[windrush]

coomsey:
Most of this topic goes over my head but still very interesting. But don’t you think it could be time to rename the thread. I’m thinking The AEC V8 Perseverance Society springs to mind. Cheers Paul

It’s like that aching tooth Paul, you know it will hurt probing it with your tongue but you still keep on doing it. As a one time HGV fitter (but never on AEC’s) I keep looking at this thread but get more and more frustrated when talk of what should have been done in the mind of a council gritter driver clouds what actually did happen when designed by experienced engine developers working to a tight budget and fitting it into an already established vehicle design. It appears obvious that CF has a downer on anything BL did, AEC and the Leyland Marathon/ 500 series engine range have both been ripped apart by him and I wonder which part of the company will suffer his wrath next, Albion possibly? A marvellous thing hindsight, we would all be millionaires if only we had had just as much foresight years ago.

Pete.

[carryfast]

windrush:
It’s like that aching tooth Paul, you know it will hurt probing it with your tongue but you still keep on doing it. As a one time HGV fitter (but never on AEC’s) I keep looking at this thread but get more and more frustrated when talk of what should have been done in the mind of a council gritter driver clouds what actually did happen when designed by experienced engine developers working to a tight budget and fitting it into an already established vehicle design. It appears obvious that CF has a downer on anything BL did, AEC and the Leyland Marathon/ 500 series engine range have both been ripped apart by him and I wonder which part of the company will suffer his wrath next, Albion possibly? A marvellous thing hindsight, we would all be millionaires if only we had had just as much foresight years ago.

Pete.

Leave it out.More like constructive criticism and disbelief at how they chose to do the job v how Scania,or even to an extent Scammell,did it.When AEC had everything they needed to compete.Although if you want to go on believing that the AEC V8/Mandator,the 500 engine and the Marathon were all competitive products to take on the foreign competition,as opposed to the question of how could they have got it all so wrong,that’s up to you.So why does my 5 years as a council driver supposedly in your view trump the 5 years working in truck manufacturing making and testing trucks and in which with that background I can understand what Scania were doing in the day and why,but no way do I get what AEC were doing,in that regard.Remind us how long did AEC survive after its V8 debacle v Scania and its V8 range ?.