We`ve had threads on Gardner,■■■■■■■ and Rolls Royce so what about AEC engines ,were they reliable or is that a myth , were they economical compared with the competion , and how did they compare performance wise like for like with their competitors , and which was the best they produced all comments welcome both good and bad
Slightly biased here as I served some of my apprenticeship with an AEC dealer in Newcastle and my first job when leaving school was with a haulage fleet 70% AEC strong so I gained a bit of experience on them. From my point of view as a young lad the engines were very easy to work on and become familiar with, obviously fitted into the Ergomatic cab models we had plenty of room to work on them compared to the older Marks with fixed cabs. Removing engines from the chassis for rebuilds wasn’t too bad a job, no great problems there on all the range. I recall doing many cylinder head gaskets but most engines of this time (mid 60’s-70’s) had the same problems, although it is well written about the lack of efficient cooling in the Ergo cabbed models because of the design.
As for reliability in service the AEC oil engine which first appeared around the 30’s in par with Leyland was a well designed and built power source that was popular abroad as well as in this country along with other British makes, not surprising as British engineering was well respected and sort after. For me the A505 of which I had most experience of, having built up many even at the age of 17 to 18 years old, was probably the most popular and well used of the range although the larger AV691/AV760 as fitted to the Mandator range was obviously the one drivers would choose, not everyone had that choice though. The 6 cylinder in line 505, an 8.266lt 502 Cubic Inch engine of dry liner design (as opposed to the earlier 470 with wet liners) produced 140-168 BHP and a 380-391 Torque rating between the years 1965-1976, more than capable of handling the requirements of the time.
AEC engines always had a deserved respect (no doubt the V8 will come in for some criticism but that engine is a story on its own and has been covered on here in the past) also many went into other branches of transport not just road haulage, if the makers were still around today I’m sure the AEC engine would be up there with the best, I was fortunate to have encountered the make as well as the engine types before its demise. Cheers Franky.
Thanks for that Frank ,i heard the AV505 was a bit of a flying machine, AEC had a turbo version ready for launch but those nice men at Leyland blocked it as they did with the V8 which at the time had had all the problems ironed out aledgedly
Hi Romone ,We ran a few AEC, 7/7 in an AEC 7/7 in MAUDSLEY ,OK a bit of head gasket trouble with it ,a couple of 9/6in mk ,5 AEC, only problem with those ijector pipes, by the gross , a couple of 505 s 1 in a GUY ,no probs ,the other in a egomtic cab ok ,but the usual over heating ,and a few head gaskets ,they did us ok best starters we ever had found them better on fuel than the Leylands ,just a bit of usless info ,yours Barry
The Mercury RTF 510G we had at home unfortunately did’nt at live up to expectations with a con rod through the block at just 23000.Tillotsons sent a big repair bill even though it was under warranty and after a lot of ear ache accepted payment for the towing charge from Leeming to Bradford.Although never short on performance the wagon suffered various other faults in the 3 and a half years we had it before selling it to some pig farmers in the Holmfirth area,nevertheless it was still in use with someone as late as 1978. As Frankydobo points out, looked at overall the Mercury was the standout 16 tonner of its era when comparing the spec to anything else around.
I drove a Mercury Tractor unit for Shorties I was a good motor UBB 805 G. Plated 26 tonne gross with the AV505 Engine It was a good motor but did have overheating problems, I allways thought that the radiator was too small, old Bob Dale that was one of the fitters agreed with me at the time but nothing ever came of it Ken Short even suggested this to the dealers at Benton at that time but it must have fallen on deaf ears, I went on to drive a Scammell Handyman after that which was totaly different all together to drive, but I still liked the old AEC, Regards Larry.
AEC engines generally had a good reputation from the 7.7 litre (1939) and 9.6 lire onwards (introduced in experimental form in 1942). The A470 gained a poor reputation for head gasket problems until the cylinder head studs were redesigned (AVU) in 1961. Thereafter they were much better. Being a simple engine to work on drivers have claimed to be able to change AV470 headgaskets at the roadside in as little as two hours. A590 and A690 engines did experience injector pipe faults. Certainly in the 1950s the 9.6 was on a par with Leyland’s O.600 for reliability and longevity in maximum weight applications. The A505 and A760 engines usually served operators very well. AEC engines were supplied to other British lorry manufacturers such as Atkinson, ERF (WW2 years), Dennis, Dodge, Rowe Hillmaster, Rutland, Guy, Seddon. Other bus manufacturers to use AEC engines were Bristol and Daimler. Overseas they were supplied to Willeme, Vanajan, and Barrieos. Probabll others I can’t just recall.
Fine engines, (although I think I’ve still got some injector pipes buried somewhere in my garage.) 
grumpy old man:
Fine engines, (although I think I’ve still got some injector pipes buried somewhere in my garage.)
I used to carry a spare set for my MK3,swinging off the coat hook,number 5 seemed to be the worst.
Excellent engines in their day and ideal for the market at which they were aimed; the companies that did not want the ‘premium’ specification vehicle, but wished to do similar work. Meanwhile being prepared to accept a vehicle and engine with a shorter life before 1st overhaul, in exchange for a lower purchase price and the option of selling for a good price after 3 to five years use. Having said that, the company I worked for kept them for 10 years.
If we concentrate on the late '60s to '70s period, it is worth remembering that there were a LOT more 4 wheelers on distance work back then. The AV505 in the Mercury eat the job, what it didn’t like quite so much was the vehicle’s 70 mph plus capability. It seemed several of ours succumbed at the foot of the M1 j10 bank south bound. In the Marshall it found life harder and certainly struggled a bit in the Mercury unit if running at 25/26 tons. The AV760 was probably the best engine AEC ever produced only let down by its habit of throwing fan blades and the problem of gearing it right.
The AV 470/ 590/ 690 were from a different era, being essentially pre-motorway designs, but like the Gardner, to a certain extent clinging to their pre-war 7.7, 9.6,11.3 ancestry and the allied maintenance and servicing interval demands.
All monobloc engines certainly easy to work on. The earlier separate crankcase engines being a slightly different kettle of fish, with their thick wall bearings or timing chains etc. The horizontal versions especially so.
I have removed the heads from three AV590s in the last few weeks. The most annoying ‘difficulty’ being trying to remove seized bolts from the aluminium coolant elbow between the two heads without damaging the elbow. This certainly requires patience.
As for changing head gaskets in two hours, well I suppose it can be done, but I can’t see how anyone can even clean round the base of all the heads studs, the top of the liners and the stud holes in the heads in that time, let alone remove and install heads as well. If it was done in times approaching those claimed, perhaps that in some way accounts for the reputation of the 470.
As for working on one these days, unfortunately it is like opening a can of worms - you just don’t know what you will find; or rather should I say, it is because you do know, that you would rather not take the lid off.
I was told ,but dont know if its true that AEC engines always performed better in AECs than in vehicles AEC supplied the engines to including the Maudslays ,why did the major home assemblers not spec AEC engines in the later years,like they did albeit in small numbers in the earlier times i.e Atkinson and ERF .Foden never ever did as far as i am aware
Hi Ramone,you,ve got onto a good subject here,AEC engines the 470 was the first AECengine we had they were fit in to GUY Warriors ,we had two of them they were on the wool job twice a week to devon or up to scotland and they never left Bradford with less than 12 ton on, they had the eaton 2 speed axle though so that helped .When we cut them down into tractor units they were expected to do a lot more work and when they were traded in fir 2 mandators they,d done over 800,000 miles each , very little trouble maybe having the same drivers helped.The 2 mandators we got next had the 691 in them and they were worked hard one of them droped a valve but that was all the trouble we had . We had 2 mercury,s both with the 505 in them ,the finest 4 wheeler ever made, both capable of doing well over70 m.p.h. Thel ast mandator we got had the 760 in it a bit more power it after 250,000 miles it had heating problems, The AEC was a great motor it just got left behind it was the best motor in the british leyland group and if they h ad inv ested in it instesd of building what they did we would have had somthing to beat all the foreign compertition.But that,s jut my oppinion,
scud:
Hi Ramone,you,ve got onto a good subject here,AEC engines the 470 was the first AECengine we had they were fit in to GUY Warriors ,we had two of them they were on the wool job twice a week to devon or up to scotland and they never left Bradford with less than 12 ton on, they had the eaton 2 speed axle though so that helped .When we cut them down into tractor units they were expected to do a lot more work and when they were traded in fir 2 mandators they,d done over 800,000 miles each , very little trouble maybe having the same drivers helped.The 2 mandators we got next had the 691 in them and they were worked hard one of them droped a valve but that was all the trouble we had . We had 2 mercury,s both with the 505 in them ,the finest 4 wheeler ever made, both capable of doing well over70 m.p.h. Thel ast mandator we got had the 760 in it a bit more power it after 250,000 miles it had heating problems, The AEC was a great motor it just got left behind it was the best motor in the british leyland group and if they h ad inv ested in it instesd of building what they did we would have had somthing to beat all the foreign compertition.But that,s jut my oppinion,
Where in Bradford did you work?
We worked mostly out of Bells but also we did a bit of dock work for Fielder an we had some of our own customers like Ogden,s at Oxenhope and Merrill,s at Haworth.
ramone:
I was told ,but dont know if its true that AEC engines always performed better in AECs than in vehicles AEC supplied the engines to including the Maudslays ,why did the major home assemblers not spec AEC engines in the later years,like they did albeit in small numbers in the earlier times i.e Atkinson and ERF .Foden never ever did as far as i am aware
As far as for Atkinsons with AEC engines,I believe it harks back to the War time years when the Ministry of Supply told Atky’s to use the AEC engine! ERF and Foden were directed to use Gardner.I’m not sure about GUY but,of course,they were big users of AEC engines both before and after the Leyland takeover of the Jaguar group.Atkinsons carried on using AEC engines into the 50’s for two main reasons,one was a shortage of Gardner engines and secondly as a direct competitor to AEC’s themselves as the big oil companies Fleet engineers liked the AEC engines in preferrence to the Gardner.Well thats what I was told years ago by someone that had worked at Atky’s.After the takeover of AEC by Leyland,Atky’s started to use more and more ■■■■■■■ engines and dropped the AEC option( or Leyland pulled the plug on them possibly!!) Cheers Bewick.
Bewick:
ramone:
I was told ,but dont know if its true that AEC engines always performed better in AECs than in vehicles AEC supplied the engines to including the Maudslays ,why did the major home assemblers not spec AEC engines in the later years,like they did albeit in small numbers in the earlier times i.e Atkinson and ERF .Foden never ever did as far as i am awareAs far as for Atkinsons with AEC engines,I believe it harks back to the War time years when the Ministry of Supply told Atky’s to use the AEC engine! ERF and Foden were directed to use Gardner.I’m not sure about GUY but,of course,they were big users of AEC engines both before and after the Leyland takeover of the Jaguar group.Atkinsons carried on using AEC engines into the 50’s for two main reasons,one was a shortage of Gardner engines and secondly as a direct competitor to AEC’s themselves as the big oil companies Fleet engineers liked the AEC engines in preferrence to the Gardner.Well thats what I was told years ago by someone that had worked at Atky’s.After the takeover of AEC by Leyland,Atky’s started to use more and more ■■■■■■■ engines and dropped the AEC option( or Leyland pulled the plug on them possibly!!) Cheers Bewick.
I suppose it makes sense really from both sides would you want to supply your competitor with engines especially when they are offering a better gearbox and final drive option and from the other side would you want to buy off 1 of your competitors knowing that every vehicle you sell a percentage was going back to AEC
As Bewick mentioned the ■■■■■■■ started to make its presence felt and many makers that didn’t fit their own engines fitted them as a further option along with Gardner, Rolls and Perkins and the AEC power plants were eventually dropped, however even around the early 70’s according to some reference books I have, an 8 wheel GUY Big J and tractor units could still be fitted with the 505, with only 146 BHP though the bigger engines were bound to be more popular.
Re the “two hours to change head gaskets on a 470”, maybe a slight bit of artistic licence there by former drivers but I certainly witnessed a head gasket change in that time on a preserved Mercury belonging to Peter Fowkes. He changed them before setting off on the Trans-Pennine run one year.
Incidentally the AVU470 I had in my preserved Seddon 16/4 was a lovely engine, never used a drop of oil in a rally season which for me was about 2,500 miles annually and did 15-16 mpg. I ran it for 9 years. I know it isn’t the same as running a lorry in revenue earning service every day, but it was as sweet as a nut. It’s only foilble was a tendency to throw its fan belts about once every year.
ramone:
I was told ,but dont know if its true that AEC engines always performed better in AECs than in vehicles AEC supplied the engines to including the Maudslays ,why did the major home assemblers not spec AEC engines in the later years,like they did albeit in small numbers in the earlier times i.e Atkinson and ERF .Foden never ever did as far as i am aware
We had an old Atki 8 legger at Fred Chappells with I think a 9.6 in and it was a belting machine.
What about the V8s were they compareable with the F89 and the 140s of the time performance wise ,and the TL12 could that live with the 290 Rolls or the 290 ■■■■■■■ again performance wise ?