AEC V8

UK PROFESSIONAL DRIVERS FORUMS OLD TIME LORRIES, COMPANIES AND DRIVERS (INTERACT
21

gingerfold:
…there were two AEC V8 capacities, the original at 740 cubic inches and the second version at 801 cubic inches. Basically the same engine as the AV 740 but with thinner cylinder liners. The AV 801 was the more reliable engine of the two and did not overheat to the same extent because the thinner liners gave better heat dissipation…

Not quite correct Graham.
The AVM8-740 and 800/801 all had liners of identical thickness.
The original cylinder blocks were bored out 5.00mm larger to accept the larger capacity liners, resulting in a thinner water jacket wall around the bore. This assisted heat transfer and is the reason that the 800 & 801 engines performed slightly better in this respect than the 740.

22

ERF:

gingerfold:
…there were two AEC V8 capacities, the original at 740 cubic inches and the second version at 801 cubic inches. Basically the same engine as the AV 740 but with thinner cylinder liners. The AV 801 was the more reliable engine of the two and did not overheat to the same extent because the thinner liners gave better heat dissipation…

Not quite correct Graham.
The AVM8-740 and 800/801 all had liners of identical thickness.
The original cylinder blocks were bored out 5.00mm larger to accept the larger capacity liners, resulting in a thinner water jacket around the bore. This assisted heat transfer and is the reason that the 800 & 801 engines performed slightly better in this respect than the 740.

Were they dry liners, then?

23

[zb]
anorak:
Were they dry liners, then?

Yes, they were ‘top hat’ design dry liners in both capacity engines.

24

ERF:

[zb]
anorak:
Were they dry liners, then?

Yes, they were ‘top hat’ design dry liners in both capacity engines.

So, on the big bore version, the reduction in the thickness of material around the liner helped conduction of the heat to the water.

I read somewhere that the flow-path of the coolant on these engines was somewhat convoluted, resulting in hot spots or parts where there was evaporation or airlocks. Is this true? Did the engines suffer from cavitation damage anywhere?

25

[zb]
anorak:
So, on the big bore version, the reduction in the thickness of material around the liner helped conduction of the heat to the water.

I read somewhere that the flow-path of the coolant on these engines was somewhat convoluted, resulting in hot spots or parts where there was evaporation or airlocks. Is this true? Did the engines suffer from cavitation damage anywhere?

It was a convoluted path, but whether that contributed to the overheating problems is open to conjecture.
It was quite a small capacity system, with a small header tank, and a combination of all these factors could not have helped matters, that is for certain.

I have not seen or heard of cavitation damage in one if these engines.

26

Thanks for the info, Mr. ERF.

27

I know the one V8 I worked on had blown cylinder head gasket trouble which an overheating AEC engine tended to do back then (Head gasket being the weakest link), I lost count of the head gaskets I replaced on the Straight Sixes. The V8 being a demo fresh from the ‘Sarf’ was very quickly returned once the gasket job was done, I never saw one again at the dealership I worked in but I did move jobs to a mixed haulage fleet not long after so my oppo’s who were still there may have had other V8’s in with engine problems. I’m not sure how many were sold in the Northeast and the fact that the demo never got to see much of the area may have meant there wasn’t the interest or knowledge of its ability. I know it could shift once we had it back on the road! Cheers Franky.

28

Evening all, the AEC V8s, a subject quite near to the heart of this “Francophile”, particularly as I saw file notes relating to France`s Willemes desire for closer, (read integration), co-operation with AEC, from 1960. This when I was sorting through assorted documents concerning Willeme, prior to their demise, and the licence agreement with Perez et Raimond for the construction of the heavy range of Willeme tractors, (150/1000tonnes).

Could the origin of the V8 have been in AECs desire, not to loose a major customer for its "loose " engines, that is Wolverhamptons Guy Motors, then under the ownership of messers Jaguar?

Jaguar/ Guy, were in the throes of a potential collaboration, and licence deal to build at the adjacent Henry Meadows works, (remember those loose fabric belt drives), a version of the USAs Mister ■■■■■■■ V profile diesel engines.

To set the context for this scenario let us remember dear Barbara Castle`s 1964 Construction and Use Regulations. 16tons on two axles, 22tons for threeaxle articulated and rigid machines, and 32tons for four axle rigid and articulated machines, (dependant on wheelbase). All subject to a 40mph limit on non Motorways, and 60mph on Motorways.

Jaguar management were anxious that Guy were at the cutting edge of HGV design and engineering, and they proposed a new range of Jaguar inspired lorries, the Big J, (Jaguar). Sankey of Telfords design for a uprated LAD style cab had been rejected by Jaguar management, even though a "refined " Invincible chassis had been equipped with such a driving enviroment by the Fallings Park “Experimental Department”.

But Coventry , (and a Rubery Owen Group Company), Motor Panels design won favour, particularly when the Fallings Park draughtsmen created a destinctive front panel treatment to set it apart from those utilised by Seddon, Floor, and ERF. The only design hange made was to replace the “mini” Feathers in our cap Indian head with a J symbol!! (Jaguar rules)!

But Jaguar / Guy envisaged a flat floor, tilt cab, high power design, and the compact dimensions of the ■■■■■■■ V series suited perfectly…and the adjacent Meadows manufacturing site was a perfect platform to manufacture under licence a “orld series” design engine range.

With hindsight we can all see the engineering, and manufacturing, and operating problems…but we are not in the 60s!!!

AEC were a major “loose engine” supplier in their own right, and Wolverhamptons Guy, a major customer to AEC during the 60s.

Guys old works manager, John Bowley, had moved to Southall as AECs General Manager.And he maintained close links with his old colleagues at the Jaguar/ Guy, and was horrified to learn of Jaguars plans to adopt, “in house” the products of a major US manufacturer. Was this the ultimate “driver”, of the effort that AEC put into creating the V series■■?

Think about it…their major loose engine customer was about to introduce a new range of “premium” chassis, all with a flat floor, tiltable cab. Not suitable for the “current” vertical 6cylinder configurations…so they were going to licence build a “state of the art” US design, “in house”…what would you do, if confronted by a potential 30% loss of business…you would ,(as AEC) try to match it.

So the AEC V8 was created, but with great difficulty, as ■■■■■■■ had a range of restrictive patents covering the V configuration. So the AEC V was created , initially at 740, then 800 cubic inches. BUT, created not for AEC initially, but for Jaguar/ Guy, and the new Big J range!!

But whil`st this “normal” business activity was taking place…along came Leyland, and the takeover/merger.

Now on another thread there has been extensive writing about the Fixed Head Leyland designs, from 700, down to 400 cubic inches, and this is not the place to comment on those writings, but that the enlarged grouping of AEC and Leyland saw the V design eventually under he most excellent Ergomatic cab is a fact. That the design lacked cooling capacity, again is a fact, (for it was designed for an installed enviroment with a far larger cooling capacity is again fact, (and I cite also the “experimental” Motor Panels designed AEC VT trial vehicle, perhaps a rival to Jaguars Big J).

That the Big J ■■■■■■■ V venture was a failure, there is no doubt. That the fear of it working drove AEC into designing the V8, well that is open to debate, and the fact that the Leyland intervention “mudded” everything…well that must be pretty certain! But that engine was never designed to sit under an ergomatic cab, that must be fact!!!

Adieu mes Braves, Cheerio for now.

29

This is an intriguing possibility. The ■■■■■■■ V and the AEC V8 share some similarities- both were aimed at a “compact” market- the ■■■■■■■ was designed to knock petrol engines out of the US class7/8 market, GB wanted flat floors in its cabs but, for some reason, did not like the idea of mounting the cab higher to achieve that. As a result, both engines were uncommonly oversquare. Both engines were duds, although I cannot see any relation between their dimensions and the durability problems, except for the AEC’s undersized crank journals.

The ■■■■■■■ was launched onto the US market in 1961 or '62, which was about the time the AEC V8 design project started. Is it taking things one step too far, to speculate that the ■■■■■■■ design influenced the AEC engineers, and they copied the mistakes?

30

Saviem you could be so right, I recall the older AEC men thought the company was mad to introduce the V engine, our very experienced Gaffer didn’t like the idea at all and said it would be nowt but trouble, by then the heavy vehicle fitting trade had witnessed the poor reliability of the early ■■■■■■■ V’s and many older hands had made their minds up about them. I recall one old lad telling me “The bloody things rev too fast and are far too noisy”, reading between the lines they prefered the old plodding smokers and the technology they were used to. I’m the same today with all the electronic gadgetry we have to get our heads around! Franky.

31

Salutations Saviem ! hope you are well and do you have any news on the LV76 rebuild/restoration for us? maybe a photo or two?

32

sorry that should have read LB 76!

33

LB76:
sorry that should have read LB 76!

Sadly, I should have left her in Bordeaux!!! The Shropshire weather has started to give her rust in places she never had before!!Just do not have the time that I hoped to get around to her. Now in our busy time…its a b…!!

Hope that you are well Bill, did you go to Gaydon?

Cheerio for now.

34

So…did Guy actually fit the ■■■■■■■ V8 for a short production run?..My father tells me they did a V8 of some make and were immensley troublesome.

35

V8 Mandator…Is that the header tank sout on the nearside…mounted very low if it is

36

Riverstick:
So…did Guy actually fit the ■■■■■■■ V8 for a short production run?..My father tells me they did a V8 of some make and were immensley troublesome.

IIRC, they put the VIN V6 in the first Big J’s. I dunno if any had the smaller VALE V8, which was used for a time by Ford. Someone will know better.

On the ■■■■■■■ thread, I posted a link to an excerpt from a book about the history of the company, and the history of those compact V’s makes depressing reading- a triumph of marketing over engineering. The big boss wanted a lightweight, compact screamer, to compete with petrol engines, and he wanted it now! ■■■■■■■ gave their engineers an unlimited budget to develop it as quickly as possible, with the result that the thing was kicked into production in less than two years. This would have been a great achievement, had the work not been riddled with the sort of mistakes that only time can rectify. This is where the ■■■■■■■ and AEC V’s differ- AEC had 6 or so years to bring their V8 to market, so they had the normal amount of time to conduct the bench tests and field trials necessary to prove the thing’s reliability. I disagree with the usual arguments, that Leyland did not give AEC enough time to develop the engine- compared to ■■■■■■■■ they had ample time.

37

Riverstick:
So…did Guy actually fit the ■■■■■■■ V8 for a short production run?..My father tells me they did a V8 of some make and were immensley troublesome.

After the ■■■■■■■ V6 troubles, the same cab with the flat floor were used for chassis fitted with the Perkins 540 V8 . Most had a 5 speed box (turner?) with an Eaton 2 speed axle.
They weren’t the most reliable, injector pipes often failed and it was not unknown for the flywheel housing to crack. The original flat floor cab was designed to tilt, in reality you had to unbolt so much stuff to tilt it made it a nonsense and it was easier to take the cab off. A large center section of the flat floor hinged up to the back of the cab to give access for most jobs (the daily injector pipe change !), however if this hadn’t been fastened down correctly it had a habit of flying up at speed (60mph+ !) and depositing the oil and diesel swimming pool that lay in the engine vee inside the cab.
Only being designed for 28t at BRS they were mainly used on light loads, car spares, tyres etc. I remember driving 3 of them COM 977K, EOG 490L and 491L one of which is pictured in Nick Baldwins BRS book, they were recognisable by the front mounted exhaust and twin air intake stacks at the back of the cab. A lot of them were fitted with the Dunlop maxaret anti locking brake system, I liked driving them, there was a lot of room in the cab without a bonnet and most of them would reach 70 mph which was probably the cause of their unreliability !

38

Having studied the AEC V8 project in some depth over the years there are still some aspects of it that remain a puzzle. For instance, when I worked for Turners (Soham) Ltd. they had been a recipient in 1966 of one of the four prototype ‘seed’ AEC V8’s. (The other fleets given them being BRS, Western Transport, and Russell of Bathgate). This was well before my time with Turners but the V8 was remembered by those Turners drivers who drove it with great affection and as being capable of storming performance that was far superior to anything else on the roads at the time. It was not remembered as being unreliable or troublesome. It leaked oil down the V, and did overheat, but not terminally and if it got hot then a few minutes with the lorry stopped but engine running at a fast tickover soon cooled it down. So, problems that were not unsurmoutable, after all it was a prototype under development. Turners had the V8 for three years and double-shifted it most of the time. AEC engineers did give it plenty of attention, but that was mainly to do with various gearbox and diff ratio trials. It had 6-speed, 10-speed and 12-speed gearboxes fitted at various times, but never the semi-auto pneumocyclic. So from the preceeding spiel it sort of blows out of the water the claim that the engine was under-developed. So, did something change in the design of the engines from prototype stage to full production when the model was launched? Did Leyland change the spec of some components to save money and that made it unreliable? Sadly, we will never know.

39

Some of the previous posts may give a hint- both AEC and ■■■■■■■ VINE V8’s were short-stroke screamers, by lorry standards. They were prone to driver abuse. They were designed to get more power out of a given engine size by the use of high engine speeds. The tuning of the inlet and exhaust would be optimal at these higher speeds, at the expense of lower-speed torque, meaning that, for the engine to provide the power in service, it would need to run faster, on a lower gear ratio. I think that this is the crux of it, assuming that the AEC’s problems with cooling and bearing wear were surmountable. Other makes, notably Unic and Fiat, built reliable oversquare V8’s, but with lower governed speeds. Mercedes OM400s and Deutz 413s were high-revving engines, but not to the extent of the ■■■■■■■ and AECs. If there is one over-riding factor which links the two engines, it is their unusually high governed speed. Berliet’s original 12.8 litre V8 was also a dud, and they solved the problems by making it a 15 litre and reducing the governed speed of it.

40

Riverstick:
So…did Guy actually fit the ■■■■■■■ V8 for a short production run?..My father tells me they did a V8 of some make and were immensley troublesome.

I believe it was the ■■■■■■■ V6 that Guy used for a short,disasterous,period when the Big J was first launched.Cheers Bewick