AEC V8

[railstaff]

gingerfold:
I have scanned the original Mandator V8 booklet photos. Apologies if the quality is not of the best, but I no longer have my original photos. Here are the front and back cover photos. (The only ones in colour)

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This Spiers of Melksham V8 was originally operated by E.L. & E.R. Jones from South Wales. It was chassis number VTG4R 039, built June 1968. (Photo by Adrian Cypher)

Nice pictures,ive seen them some were before,I think Spiers were big AEC men,and ran them long after their time(not to take anything away from them) mainly 760,s(I think)
Air products shot taken some were in middlewich near their base.
Humber ware housing again had a large fleet of mandators,not sure on engine usage though.

[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?

[gingerfold]

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I wonder what that load of timber weighed?
(Did A. Ferguson become Ferguson’s of Spean Bridge? If so they are still in business).

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[railstaff]

Absolutley brilliant,any interia shots of the anglo continental high roof model please.

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The installation looks a lot better with the higher set up American looking cab.I notice no fan cowling with it.

[carryfast]

ERF:
Thanks for another plethora of informative posts CF.

You certainly provoke thought, and I’m sorry to contaminate your input with my own musings, but until now I hadn’t consciously recognised certain things you mention.

For instance, Keith Roberts & Co - why on earth they would be gushing with enthusiasm for a design they knew to be compromised and unconcluded in a Leyland issued launch promotion, I cannot begin to imagine.

Thanks also for putting me straight on the opinions expressed to me personally by Perkins development engineers. Until now I had no idea that they were just being diplomatic to others in their profession when they expressed respect for the AEC V8 designers, and stated their opinion that the AEC design was very nearly right. I now see the light

I am slightly puzzled though. You obviously have a great deal of practical experience in the design of the large capacity high speed Diesel engine. Do you not think that the 114mm stroke of the AEC design was perhaps a little short for it’s 130mm and 135mm bore? I don’t think you’ve mentioned it before, but wonder if you think it contributed to the engine’s ultimate failure, notably it’s lack of power, torque and on road performance so often reported by operators and drivers of the model?

Thanks also for pointing out the merits of forged vs cast manifolds (above).
Now duly noted.

You mean its massive torque output to the point of not being able to match the BMEP of the 690 or a Gardner.Or all the benefits for operators of it wrecking its end bearings by 50,000 miles.

As for Robert’s and Co,Friars definitely mentioned the word horrified but what he really meant who knows.But yes gushing praise by the rest a bit like a comedian laughing at his own jokes as I said in the same way that Ford’s designers would have been over the moon with putting the Cosworth DFV in the Zodiac Mk 4.All maybe except for Stokes who’s comments seemed to me to be more like reserved judgement.Obviously followed by letting Scammell put the 8v71 in the Crusader with his blessing.You know an engine which really did make a reliable 800 lb/ft and 300 hp from a compact small capacity package and stayed together in the process.But how could its designers have known that AEC were going to make a vehicle in which even that wouldn’t fit.

As for those Perkins development engineers you seemed to have missed the glaring question why didn’t they retain the AEC’s bore stroke ratio and instead went for an under square design in the case of the 640 ?.Nothing to learn from Fogg and Roberts’ mistake there obviously and just coincidence.

As for forged manifolds.No if I’d have read your post correctly I’d definitely have posted some information showing the generally accepted idea that fabricated headers usually result in a bit more power than restrictive cast manifolds.Definitely not the superiority of forged crankshafts over cast ones.

[erf]

Carryfast:
You mean its massive torque output to the benefits for operators, But yes gushing praise as I said in the same way that designers would have been over the moon with Stokes comments. seemed to me an engine which really did make hp from a compact small capacity package But how could its designers have known

AEC were going to make a vehicle which had Nothing to learn from Fogg and Roberts’

As for post I’d definitely post some information showing the restrictive superiority of cranks

I quite agree with everything you’ve said there.
Or have I misunderstood / slightly misquoted your own words…?

[gingerfold]

The Enigma of The AEC V8 Engine: Why Was It Ever Produced

Extracts from an article by Robert Fryars, former AEC Director of Engineering and Leyland Group Chief Engineer.

This will answer some questions, and no doubt raise others, but it does explain plenty. We need to start in 1961.

At that date AEC (or ACV group) was an independent company but it was seeking a partner. The Board of Directors believed it needed to be part of a larger grouping to gain benefits from economies of scale that would allow them to compete in Europe and to counter the threat of continental manufacturers. In mid-1961 ACV was in quite advanced talks with BMC about a merger.

In the midst of these discussions Guy Motors went into receivership and it was acquired by Jaguar Daimler. Jaguar then entered discussions with ■■■■■■■ for them to manufacture ■■■■■■■ V6 and V8 engines for Guy. These engines were to be produced in the old Henry Meadows factory next door to Guy.

AEC was an important supplier to the “loose engine” market, and Guy was a large customer for AEC engines. John Bowley, AEC General Manager, met with Lofty England of Jaguar and told him that AEC could match whatever ■■■■■■■ was offering.

John Bowley requested a V engine study from his engineering team. Bob Fryars and Keith Roberts obtained copies of the ■■■■■■■ V engine patents and they discovered that ■■■■■■■■ cleverly, had patented the best stroke and bore ratios. To avoid infringing the ■■■■■■■ patents the options were either a long stroke tall V engine, or a squat over-square V engine.

It was decided that an over-square V6 at 90 degrees, an angle essential to fit in a chassis, would be very rough running, so a V6 option was discounted.

So, AEC was looking at a very over-square V8, a design which was unprecedented and one that was well outside of any direct injection combustion chamber relationship.

Engine noise. Theo Priede, then of CAV, had devised a formula linking Diesel engine noise emissions to the square of cylinder bore diameter and to rotational speed. An over-square Diesel would be very noisy, adding to the difficulties.

A short stroke in-line research engine was made by AEC. A decision was taken that a V8 scheme would only go ahead if it could be fitted under BMC’s new FJ cab.

1961 turned out to be a bad year for the motor industry and the UK economy in general.

John Bowley at AEC had his V8 engine brochure by late Spring 1962. (But no engine)

In late 1961 Rolls Royce complicated matters by suggesting a tripartite arrangement with themselves, ACV, and BMC. This was soon discounted and merger talks between ACV and BMC resumed. ACV believed that the lighter, mass produced BMC commercials would complement the AEC premium range.

1962 the ACV / BMC merger talks were well advanced, there was a good chance of an agreement, and outline terms were drawn up. Then BMC’s financial forecast for the year looked grim and ACV suspended talks, ultimately to walk away.

ACV was high and dry, still needing a partner, but no suitor in prospect. ACV previously had considered Scania Vabis, but had not thought it to be practical. There was only one viable course for ACV, and that was Leyland Motors.

But Leyland itself wasn’t in a good position and it was in dire straits financially. It’s heavy vehicles were overweight and expensive. Leyland’s propitious purchase of Standard Triumph was threatening to bankrupt Leyland itself. In the background Chrysler Motors was watching with events with interest, waiting to pounce and buy a controlling stake in Leyland.

Enter the saviour in the shape of Stanley Markland, who had turned Albion Motors into a profitable and efficient operation. Markland was parachuted into Standard Triumph and by heavy trade discounting he started to quickly reduce a huge stockpile of cars. His was a very risky strategy, but by generating badly needed cash flow it enabled him to keep the business afloat and make economies in manufacturing.

With matters improving Leyland saw off the Chrysler threat and opened talks with ACV. Within three months of negotiations starting a deal between ACV and Leyland was agreed in August 1962. Donald Stokes was heard to comment “buying AEC will solve all our problems”.

All AEC projects were discussed with Leyland and nothing more was heard about the AEC V8 engine project for two years.

In that intervening two years, in secrecy at Leyland, development and investment of the Tattersall 700 engine had begun. This would eventually be downsized to the fixed head 500 engine. The first prototype 700 engines disintegrated within minutes of going on test, irrespective of the fact that they were too big and heavy to fit into any road going vehicle. (The Tattersall 700 engine was loosely based on the Leyland battle tank engine).

When the results of the 700 engine tests were presented to the board panic set in because Leyland was now devoid of a higher power engine. So in late 1964 AEC was urgently requested to prepare an updated concept paper for its V8 engine, with the proviso that it had to fit under the Ergomatic cab, introduced at the 1964 Commercial Motor Show.

[cav551]

gingerfold:
The Enigma of The AEC V8 Engine: Why Was It Ever Produced

Extracts from an article by Robert Fryars, former AEC Director of Engineering and Leyland Group Chief Engineer.

This will answer some questions, and no doubt raise others, but it does explain plenty. We need to start in 1961.

AEC was an important supplier to the “loose engine” market, and Guy was a large customer for AEC engines. John Bowley, AEC General Manager, met with Lofty England of Jaguar and told him that AEC could match whatever ■■■■■■■ was offering.

John Bowley requested a V engine study from his engineering team. Bob Fryars and Keith Roberts obtained copies of the ■■■■■■■ V engine patents and they discovered that ■■■■■■■■ cleverly, had patented the best stroke and bore ratios. To avoid infringing the ■■■■■■■ patents the options were either a long stroke tall V engine, or a squat over-square V engine.

The issue of the ■■■■■■■ patents went to court but not with AEC. If I have read this lengthy legal argument correctly then AEC could probably have gone ahead. But I could be wrong.

law.justia.com/cases/federal/di … 9/1948328/

[gingerfold]

Concluding the above post with more from Robert Fryars… (Quoted verbatim)

“With the corporate instruction to proceed with a new engine and chassis carrying a much better ‘walk through’ version of the Ergomatic cab all of us at AEC were delighted. But soon after came the edict that no further development be permitted on either the A760 or A505 engines”

“By the time I transferred to Leyland in mid-1966, the V8 Mandator was well on the way to inception. Instructions given to me at Leyland were clear: I must have nothing more to do with AEC. When still later, Donald Stokes was forced to abandon the 400 bhp gas turbine development, Dr Albert Fogg, Corporate Engineering Director, proposed that AEC develop an increased bore V8-810 for 350 bhp as a potential replacement.”

“With Mac Porkess then in charge of engine research at Southall, good progress was made on that, until with Bertie Fogg retired and the Common Market more or less agreed on truck gross weights for which the AVT770 (later TL12) turbocharged to 280 bhp was ideally suited. And with noise emissions becoming a major issue, I had to recommend the in-line engine against proceeding with the V8. That nearly cost me my job.”

“In conclusion, I believe that the V8 only ever came into production as a second string solution to the almost unbelievable shambles that the highly secretive Tattersall engine concepts had produced at Leyland. I have always been proud of how well AEC people designed and developed the V8 and the walk-through Ergomatic cab. In many ways it was a far better chassis / cab concept.”

“But an over-square V8 was never going to be capable of meeting noise, and later, exhaust emission regulations. On both counts, Diesel engine bore-stroke relationships would optimise at very conventional ratios for all vehicle applications.”

So there you have it folks, from someone who was there and who was involved in a very senior position

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This just gets better and better,between Gingerfold and Cav551 they are legends with information.

[carryfast]

cav551:
I do not wish this to result into a diversion from the theme of the AEC V8, but perhaps we should remind ourselves that what is still revered almost worldwide as probably the most successful engine for its application was spawned from: muddled thinking, obstinacy, failure and numerous fundamental changes in design not just during experimentation, but to the engine first put into production.

As has been said several times, we are viewing the AEC V8 with the benefit of hindsight and the knowledge of roughly another 60 years of knowledge, bitter experience, improved materials and techniques, oils and numerous other benefits that time has enabled. Furthermore it is not just computers which have made the difference to design, we should not forget that these engineers were not even using calculators, they were limited to books of tables, slide rules and manual arithmetic. All known previous data had either to be remembered or laboriously looked up in written indeces - there were no search engines to miraculously point to a possible answer. It is no wonder that they deserve respect for their efforts regardles of what happened in the short term. We simply do not know what their project might have produced.

I refer to this other engine to make the one specific point so please no lengthy discussion about it on this thread… start another one perhaps in Bullys.

For anyone who is interested in the story or wondering to what I am referring, then one article is here:

enginehistory.org/Piston/Rol … /RHM.shtml

Revered and successful aren’t words which would ever have applied to the AEC V8 powered Ergo.

While how can you possibly compare the way over square AEC V8 design premise with that of the under square Merlin.While surely any comparison with the 137 x 152 wet liner Merlin gives more weight to the idea of a V8 based on the architecture of the 130 x 142 690.Oh wait that wouldn’t fit in the Ergo dustcart.

While Napier showed what making a short stroke aero engine took.In the form of the Sabre.IE around 10 more litres and twice as many cylinders than the Merlin and certainly no less than a 120 mm stroke to make it work and even then still not without loads of reliability issues and certainly no good as a heavy bomber engine.

No surprise that it was the Griffon that lived on in the Shackleton until 1984 based on the design premise of maximum possible power for the least possible engine speed ( it’s all about torque ).No need for computers or modern materials or 21st century hindsight in realising that simple fact in moving a lot of weight as reliably and efficiently as possible.Also no need for computers and 21st century technology to do whatever it took to make it fit in the Spitfire which was effectively a different aircraft at that point.Which of course AEC also had in the form of the 3 VTG.

So there we have it Leyland deliberately chose to sabotage itself with the Mandator V8 instead of going for a 690 based V8 in the 3 VTG.

[carryfast]

railstaff:
Again another superb post,without covering old ground again,reading some of CF,s contributions one thing seems to have slipped his mind and in the AEC literature it has been refered too.Over the last 50 years commercial vehicles and mainly tractor units have grown,for an example park a mandator or B series next to a modern Volvo,scania or MAN,and the oldies look like a transit van in comparison,but more over frame widths have also increased,all frames now taper out at the front,back then all frames were parallel.
AEC engineers would have designed the 740/800 to fit with these dimensions,and thus refered to the engine themselves as being “compact”.As ive said before enlarging the stroke on a Vee configuration is not that simple when space is an issue and history tells us this.They done a bloody good job with the resources they had.

Which leaves the obvious question what did Scammell and more importantly Scania both do which AEC didn’t to at least be able to use the 8 v 71 and more importantly the Scania V8 respectively ?.Bearing in mind the same available early 1960’s design technology in all cases.

On that note did anyone at AEC even bother measuring available space in the 3 VTG for example v the dimensions of the Scania V8 motor ?.

[carryfast]

gingerfold:
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Do we have any comparisons of the durability of the 180 hp 2,200 rpm rated 801 v all of the higher rated road going applications ?.As I’ve said that would have been my solution to the issues possibly to the point of using it to replace the 500 series.The answer to that question would obviously either prove that idea or disprove it.Leaving the question if it did improve matters then why would they have chosen to knock the V8 on the head and struggle on with the 500 ?.