Expediency starts with an E.
Nobody can truly escape their past, a statement that holds as true in the automotive domain as it does in the human one. Legacies, either from prior or existing BLMC products would become a leitmotif of Allegro’s dolorous story – a statement underlined by the issues surrounding its powertrain, which consisted of both the venerable A-Series engines and the more latterly developed E-Series units, inherited from the Maxi programme.
Allegro’s predecessor had been offered in 1098 and later on, in 1275 cc versions, the latter being something of a late addition to the range and one which proved popular with the buying public; improved performance having become a selling point with customers given the manner in which the UK’s motorway network had grown. It is likely that a further stretch in capacity would have gone down better still with more affluent buyers, but when a larger capacity engine did become available, it became earmarked for other purposes[1].
The powertrain factor
The E-Series engine family had never been intended for ADO16. It came about primarily because former BMC Chairman, Sir George Harriman didn’t believe that any of the carmaker’s existing engine families would be right-sized for their midline car (Maxi) in development at the time[2]. In this he was backed by (Sir) Alec Issigonis, who advocated a somewhat unorthodox design which provided for a compact in-line six version to be built alongside. The story behind the E-Series engine has been told in greater detail elsewhere, but suffice to say, that in its more workaday garb, it feel a good deal short of ideal, not just in performance, but also in refinement.
The use of the E-Series powertrain for Allegro was based on necessity, with a side order of expediency. Firstly, owing to the fact that no suitable larger-capacity powertrains were available for a front-drive application (and a new one was out of the question) and secondly, owing to the factory that built them being woefully underutilised. And while there was a clear desire on the part of BLMC’s marketing leadership to offer a wider engine choice to take advantage of both the customer’s greater spending power and upmarket aspirations, there was little commercial precedent in offering an engine of close to 1.8 litres in such a compact package[3].
Therefore, while there was a certain commercial logic to the fitment of the 1485 cc E-Series unit to Allegro, the provision of the larger 1748 cc engine appeared to defy this. That BLMC elected to go this route suggests two things: firstly (as previously discussed) that Maxi’s failure to meet its sales objectives required excess E-Series capacity to be diverted and secondly, that performance of the smaller engined models was sufficiently lacklustre that a larger capacity model was deemed necessary to match the performance of rivals.
Certainly, there appeared to be little worth talking about between the real world performance of the two E-Series engines as fitted to Allegro[4], at least until the twin-carburettor version of the 1750 became available in 1975. It is also worth considering that in Car’s June 1973 special supplement, LJK Setright observed (quite correctly) that all Allegri were offered in a very mild state of tune, although the reasons for this he did not care to speculate upon.
Illustrating this in the most graphic manner was Car magazine’s February 1974 Giant Test, which pitted an Allegro 1750 against a Citroën GS 1220 Club and an Alfasud 1200; all three closely matched on price. BLMC’s offering mustered a superior 80 bhp (DIN), against that of 60 bhp for the smaller capacity GS and 63 bhp for the still smaller Alfasud. Car also observed that Allegro’s larger swept volume lent little advantage in performance terms, being only very slightly quicker in real-world conditions. Furthermore, when it came to the manner in which this performance was delivered, the Continental pair left the UK offering in their Kamm-tailed wake, both being beautifully smooth running and rev-hungry. Car’s description of the E-Series being “the chief albatross beneath which the Austin has to suffer”, left little room for ambiguity.
A further impediment to Allegro’s performance, and especially its top speed was the fact, as pointed out by Autocar, that while its shape offered less drag resistance to that of its ADO16 predecessor, its frontal area was 10% greater. Allegro was also both taller and wider than either GS or Alfasud; both cars cleaving a cleaner passage through the air; the Citroën in particular. Furthermore, while Allegro was lighter than ADO16, it weighed more than either Alfasud or GS[5]. Of course, where the E-Series did score over its Continental rivals was in fuel economy, owing to its greater torque and higher gearing – one of the engine design’s main virtues being its efficiency.
But there was more to the E-Series powertrain than simply the engine unit. The gearbox and more to the point, the linkage and change quality would remain a bugbear of varying degrees throughout the life of both Allegro (and Maxi). Ranging from at worst, abysmal to at best, almost acceptable, this aspect of the powertrain served to underline the compromises inherent in the E-Series concept, a matter highlighted in Barney Sharratt’s Men and Motors of The Austin, where engineer, Bernard Johnson was quoted as saying, “…the whole gearbox underneath E-Series wasn’t really big enough. The distance between the shafts was too small, which meant the synchro cones were also too small.”
Sluggish it may have been in off the shelf form, but the E-Series could be made to get out of its own way – Daniel Richmond’s Downton Engineering having produced a tuning package for Maxi, which would ultimately form the basis for the upgraded unit fitted to the top-line Maxi HL. The twin carburettor version of the 1748 cc E-Series developed 95 bhp and as fitted to the post-1975 Allegro HL, made for a genuine 100 mph car, a figure which had conclusively eluded the earlier single carb version.
However, little of this made a palpable difference to Allegro’s commercial fortunes, the 1275 cc version making up the bulk of sales[6]. This became especially acute from 1974, when larger capacity engines fell dramatically out of favour in the wake of the October 1973 petrol shortages and the crisis of confidence which followed. What few Allegros that were sold elsewhere were predominantly A-Series equipped, an engine which was entirely adequate[7], if no ball of fire[8] in the Allegro body.
There may be some credence to the suggestion that Sir Alec Issigonis shared with Lancia’s Antonio Fessia an ambivalence towards higher power outputs. Was Issigonis, like his Turin counterpart locked into pre-war thinking when it came to the subject of power to weight? Certainly, the compromises packed into the E-Series concept made for a range of engines and gearboxes which were unsatisfactory in any application and failed to provide what was required – a future-proofed, modular, and adaptable powertrain[9].
Allegro paid dearly for its legacies.
oo0O0oo
[1] 1275 cc was as far as the A-series could feasibly be stretched – according to its manufacturers at least – and getting it that far required a great deal of work in itself. The 1.5 litre E-Series was fitted to the Antipodean market Morris 1500 and Nomad, but never to any UK market ADO16. It was also of course, the launch engine for Maxi.
[2] Another rationale for E-Series over the expanded A-Series was that Harriman believed (or was led to believe) that such would be the volumes for the new mid-sizer, there would not be sufficient A-Series capacity to supply ADO16 and 14 models lines (ADO14 having been initially schemed with a 1.3 litre engine. Furthermore, by then, production of the B-Series engine in an appropriate engine capacity had ceased.
[3] LJK Setright observed in June 1973 that some 12% of new car buyers opted for high-performance versions, a section of the market well worth pursuing in his view. Whether any Allegro models could actually fit that description however was left unsaid.
[4] Car’s Ian Fraser reported in June 1973 that “the 1500 has a better torque curve than the 1750 and this tends to make for sweeter performance overall. However, apart from the more responsive feel of the 1500 engine, there is little to pick between the two sizes on the road.” Fraser went on to describe the performance of the 1750 cc engine as “slightly disappointing.” In the same issue, LJKS reported that certain Allegri were quicker (in certain speed ranges) when fitted with the AP auto-shifter. However, this was not found to be the case with the 1500 cc Automatic model, which was notably less accelerative than the manual.
[5] Autocar, in their report on the Allegro 1750 noted that the additional weight (100 lb) over the nose increased understeer to such an extent that they felt the larger engined version was nowhere as well balanced in its handling.
[6] In a similar manner to Marina, the 1275 cc model proved the sweet-spot of the range and for this reason, and for simple commercial ones, the 1300 Allegro would prove the best-selling.
[7] The 1100 Allegro was considered something of a slug, owing to the car’s weight and the low state of tune of the smallest available A-Series unit.
[8] Autocar observed that the 1300 Allegro they tested in May 1973 was notably down on performance (acceleration and top speed) against that of both the 1.3 Marina and its similarly engined predecessor, both tested in 1971. They reported that the induction system had been modified by BLMC to comply with upcoming EEC emission regulations, concluding that the A-Series now developed less power. Nevertheless, they found the 1275 cc unit to be lively and eager in use, also praising its smoothness and quietness in operation. Praise for the 1.3 model was echoed by Car’s Ian Fraser, who described it as “playful”, “chuckable” and “better balanced”.
[9] Flexibility in tooling was key to making any powertrain programme pay for itself. It was a sound principle which Issigonis either didn’t fully grasp, or chose to ignore. Whichever, it was to prove a very expensive error, which did his reputation no end of harm.
Sources and acknowledgments – See Part One
Driven To Write 
The claims of the UK aftermarket tuning industry always confused me. Many were just cottage industries run by people with various levels of skill but some, like Downton, were able to produce appreciably better performing engines with little loss of economy, and in some cases improved economy. Why couldn’t the original engineers?
BMC’s involvement with Downton seems to be another case of Stokes & Co shooting themselves in the corporate foot. Eccentric, but undoubtedly talented, and employing others equally talented, Daniel Richmond was employed as a consultant and improved various anaemic BMC products throughout the 60s. But just like John Cooper, he was informed that his services were no longer required after British Leyland were formed.
Possibly “We don’t need consultants” is BL’s enduring epitaph.
Eóin, this must be the most comprehensive analysis of the Allegro ever made in the Internet! Thanks a lot.
My only contact with one of these BL beauties was seeing a S-reg 1300 pale yellow in my city, in a surprising good condition, about seven years ago. Why somebody would want to drive a 40 year old Allegro to Sevilla is a mistery, but here it was, nonetheless.
b234r: I doubt that. I’m sure the good people at AROnline have given a very thorough account, to say nothing of the books etc written on the subject. But I appreciate the sentiment.
I’ve read a good part of the AROnline output, though by no means all: I think that would be a superhuman feat. Of the prolific Dutch writer Simon Vestdijk, people used to say that he wrote faster than God could read. Something similar might be said about Keith Adams &Co. That said, I find the DTW version easier to follow, if less detailed (these things are usually inversely related). Thanks, DTW.
For the Allegro everything seemed to conspire for it to become a car with few redeeming features (dumpy, careless styling; strained labour relations; somewhat dysfunctional management/corporate culture(s); declining reputation for its maker after the ADO17 and 14; lacklustre engines; difficult financial cicumstances for an independent maker in a smallish market). There was nothing positive or compelling for the public to latch onto. As such it was probably destined to fail. It also, along with the Marina, fits nicely into the “Decline and Fall of the Leyland Empire” narrative. And we humans love our narratives.
Arguably (as I understand it at least), the DS/ID from Citroën never got the engine that it was designed for either, but the rest of the car was good and sensational enough to compensate. Its offspring suffered a slow decline into irrelevance not entirely unlike BLMC.
Agreed. I too have read much of the AROnline material, and I think Eóin’s material is easier to read and strictly to the point. Breaking it up into short segments addressing specific aspects of the subject makes it easier to take in than a rambling narrative that covers all points.
We know that the B-series engine worked in transverse FWD applications, as it was so fitted to ADO17, and had been available in 1.5- and 1.6-litre capacities. Wouldn’t it have worked in the Allegro? Was it too big/too old?
Jonathan – yes, I think emissions were a problem, as were weight and size (and refinement, for that matter). I’ve don’t think a B-Series would suit a transverse layout.
That said, the B-Series sort of morphed in to the O-Series, which was fitted transversely, so I’ve just contradicted myself within 3 sentences, which may be a record. Trying to apply logic to anything related to British Leyland is a somewhat fraught exercise at the best of times. They ought to be given a posthumous award for services to management theory and for providing content for journalism.
Gentlemen: The B-Series was also fitted to the ADO71 (18/22 Series) from 1975 until 1978, when it was supplanted by the 1.7 litre O-Series unit. (The 2.0 O-Series arrived in 1981). Emissions were unlikely to be a problem with the B-Series, I would suggest, given that this engine was also fitted in detoxed form in the MGB for the US market, who at the time enjoyed the most stringent emissions regulations anywhere.
I can’t say I know definitively why the B-Series was chosen for ADO71, as against the 1750 E-Series for example, other than the fact that BLMC’s marketers believed that Allegro (and Maxi) would hoover up all of the available (four cylinder) E-Series volume, which as we now know, did not happen. There was also the continuity factor. The powertrain was available and proven, having been fitted to ADO17 (Austin 1800), if rather old. It’s not as if the E-Series was a palpably better prospect, even if the twin carb 1750 was probably more powerful.
Charles: “Trying to apply logic to anything related to British Leyland is a somewhat fraught exercise at the best of times. They ought to be given a posthumous award for services to management theory and for providing content for journalism.”
You said a mouthful there…
My brain cell must need switching off and switching on again, as the ‘60s 1800 range had, of course, the B-Series engine transversely mounted, as Jonathan said. I guess it would still have been too large for the Allegro, though. At least they weren’t tempted to use those doors, again…
I can’t see a case for putting the B-series powertrain in the Allegro. The E-series was in production when Allegro development started, and there was plenty spare capacity thank to the Maxi’s abject failure to meet sales projections.
On the other hand, if the Maxi had been developed to use the ADO17’s engine and transaxle as a temporary measure until the E-series was ready, it could have been brought to market around two years earlier, and allowed time for the E-series to be de-bugged, rather than rushed into production.
And yet it’s possible that an ADO17 powertrain was being considered for the Allegro in the shape of the ADO68/67 proposal (c. October 1970) for a Capri rival:
In this case it was the 2227cc E6, presumably with the B-series four speed gearbox, which was largely unchanged from that of the four cylinder 1800s. If the will had been there, it’s likely the E6 could have fitted; the Allegro front track is less than two inches narrower than the ADO17 1800/2200.
Also the E6 was sized to fit the ADO17 engine compartment with a side-mounted radiator and fan. For production, the six cylinder cars had a front-facing radiator and an electric fan. Which means that the E-series never needed to have such closely-spaced cylinders. If you have an idle moment with a bore / stroke calculator, try working out what could have been achieved with 88-90mm bore centres, rather than the 82mm (approx.) dictated by Issigonis’ eccentric notions.
Based on how it performed in ADO17 and ADDO71 would an Allegro with the 2227cc E6 have been substantially quicker than one with a Maxi spec 105.5 hp 1748cc Downton tuned engine?
Would it have even been worthwhile in spite of any drawbacks due to the Allegro’s smaller size and additional weight of the E6 at the front relative to the E4? Also short of it being reduced down to 2-litres, an E6 Allegro would have been pitted against some unusual company where the only other rivals with 2-litre+ engines were the RWD Chevette HS/HSR and Lotus Sunbeam.
Based on the look at the ADO68/67 proposal, it would have needed a more attractive rebody or a front grille more like the South African built Viva-based Chevrolet 1300/1900 and Rekord D-based Chevrolet 2500/3800/4100 respectively.
That said in a scenario where the O-Series appears some 10-15 years earlier, could see a properly developed upscaled larger block E-Series being potentially used as the basis for lighter and more modern successor for the O-Series.
The E series engine, even more than his ever more tragic post Mini cars, stands as a testament to how incredibly foolish it was to allow one very blinkered and dogmatic man to lead all BMC engineering development around by the nose.
One of the few obviously right things Leyland ever did was to sideline Issignois.
Perhaps Uncle Alec was merely engaged in a long campaign of revenge – all the fault of that nasty Mr Lord for not letting him put the engine he wanted to in the Morris Minor?
Canning the Flat-Fours, 1100cc MG version of the Wolseley 4/50 and Wolseley Eight engines were William Morris’s doing.
Whereas Lord though did pull the plug on the 918cc Wolseley Eight engined Minor that was to grow to around 950-980cc, it was simply because it made sense to opt for a modern post-war OHV engine design than an adapted pre-war design* even if the latter was pretty much ready to go into production when it was cancelled.
Had the Wolseley engine been introduced in the 1948 Minor under a non self-sabotaging Morris, it is doubtful the former would have erased the A-Series which preceded the merger. Though could see it lasting until the mid-1950s to early/mid-1960s at most, sitting between the 800cc A-Series and 1200cc B-Series depending on its latent potential beyond 950-980cc.
*- Basically a smaller version of the 1140-1466cc Morris X-Series engines. https://www.mgccyregister.co.uk/technical-information/the-xpag-files/xpag-data/the-x-factor-origins-of-the-xpag/
In the mid 70s, there were newspaper stories about back wheels coming off Allegros, and fears of a safety issue. It transpired that some mechanics, accustomed to spannering ADO16s, were torquing up the rear hub nut on the assumption it had the same ball-bearing hub. Since the Allegro had a taper-roller hub it needed to be tightened gently until the wheel no longer spun freely, then backed-off slightly and peened or split-pinned.
There could be a whole article on the truth and lies surrounding BL cars of this period. Wheels falling off, screens popping out, more aerodynamic in reverse, workers lunches found under seats etc etc. Perhaps there will be?
Richard – there is a section on this in AROnline.
https://www.aronline.co.uk/facts-and-figures/features-old-wives-tales/
Some of the stories are regrettably true, though. I recall that a Maxi being road tested by a magazine was delivered with an apple in the ventilation system.
Thanks Charles, that’s a good find!
Also, thank god DTW doesn’t inflict all the intrusive adverts on readers that AROnline delivers. It makes reading on a phone almost impossible.
Know it have been touch upon previously although while understanding BMC had a tough time stretching the A-Series to 1275cc with old transfer machinery and production tooling, am perplexed as to why they were able to be further stretched to seemingly viable 1293-1380cc engines. With the implication being that new production tooling etc (akin to the redesigned 2nd gen South African A-Series and A-OHC project) would have allowed an undersquare path towards reaching 1380cc (via 70.6-71.5mm bore and ~86mm stroke).
Do agree however the E-Series should have been more like the Nissan E OHC, Honda D and Renault Cleon-Fonte engines as effectively a “Super A-Series/Super A-OHC” capable of easily slotting into the engine bays of the Mini and Metro, rather than an pre-war inspired subpar successor to the B-Series and C-Series. The modular approach was the right one, yet not to the extremes seen in 9X and E-Series rather just as a 3/4-cylinder engine later seen in the early stages of the K-Series project where the 3-cylinder could be used to expediently replace the 848cc A-Series.
Fwiw both the Nissan A OHV and E OHC engines were said to be quite a bit lighter compared to both the BMC A-Series and E/S-Series engines. With Nissan actually being able to make the E OHC about 10kg lighter over the A OHV (that depending on size reputedly ranged from 87-97kg+ via info online) as well as shorten overall length by 48mm (1.89 in) to accommodate the in-line transaxle design.
Seeing how Nissan further downsized the E OHC to create the MA for the original Micra that evolved into the CG and CR (as well as upscaled to create the O Series-esque Nissan CA/CD) engines demonstrates how BMC could have easily embraced a similar approach to replace both the A-Series and B/O-Series engines.
No idea how compact the O-Series was over the B-Series for it to fit into the Allegro apart from the former being about 20kg lighter against the latter, yet an earlier version of the above as well as the “Super A-OHC” would have butterflied away the necessity for the real-life E-Series to exist let alone for its development trajectory to evolve the way it did under competent management.
That just leaves the issue of the Allegro (and Maxi) gearbox, really Issigonis should have expanded on the end-on layout in the FWD Minor prototype for both ADO16 and ADo17 (with the Mini featuring a provision for end-on later on), or failing that later swallowed his pride to follow the example of Dante Giacosa.
“Was Issigonis, like his Turin counterpart locked into pre-war thinking when it came to the subject of power to weight?”
Eoin. That’s an interesting question about the mindsets of Issigonis and Fessia. Back then I was certainly disappointed that cars like ADO16 (which I experienced) and Lancias (which I might have fantasised more about had their published performance figures been more impressive) seemed relatively sluggish. But did they just think ‘that’s as powerful as a good handling car needs to be’? And were they right? Though there is a difference between slow and stodgy (Allegro) and relaxed but willing (Fulvia).
I get the sense from the reading I have done on the subject that Alec didn’t want his cars to be too quick. I recall him being quoted as saying something along the lines of, ‘if you give people margins, they’ll use them up’, but then, a lot of Alec’s pronouncements were probably said tongue-in-cheek; he was known for his impish sense of humour.
Nevertheless, this position, if correct, sits rather oddly with his own well-documented press-on driving style (he did formerly race). Alec was big on active safety, making much of his design’s wheel at each corner layout (for stability), low roll cornering characteristics and safe understeer-biased handling. Of course, passive safety was another matter altogether, but he wasn’t unique in that; no Béla Baréyni was Issigonis.
It also seems at odds with his principles of giving the customer more. Even the somewhat ascetic style of exterior and interior design seemed to reflect these egalitarian aspirations – that nobody should be denied the most interior space, driver engagement, or safe, consistent road behaviour, regardless of social stratum. Yet here was a staunch Royalist, who delighted in hob-nobbing with the ennobled and celebrated in Monaco and other Sixties Jet-Set locations.
Returning to engines. Another recollection was that later in his career, he is said to have admitted that he wasn’t very good at designing engines, but believed he had more latterly leaned how to make good ones. Certainly, for much of his career, he really ought to have been kept at arms length (or further) from such matters. It clearly wasn’t his metier.
But then, one thing we can safely say about Alec, was that he was a man of contradictions.
Eóin, could you recommend a biography of Issigonis? He seems a facinating man.
Hi Peter. If you haven’t already seen it, you might enjoy this four-part series on Issigonis and his impact on BMC and its successor companies I wrote with Eóin’s help back in 2020:
Peter: Since the ‘official’ Gillian Bardsley biog has already been mentioned (very thorough, if somewhat dry), I will mention another, which has been recommended by those whose opinions I value. (I haven’t had the pleasure as yet) “The Man Who Made the Mini” by Jonathan Wood.
Thank you Daniel. I hadn’t discovered this ‘motoring club’ back then. (It feels more like a group of friends than a website!)
As with many aspects of BMC/Leyland, it all seems to come back to engines. Specifically their dogged insistance on making do with what was in production already rather then developing it to meet the expectations of the market. At a time when people were starting to look for a bit more verve in their motoring experience, the A-, B- and O-series seemed to come up short and/or be rather disconcerting if not unpleasant as they went about it.
Was there really any point in offering the 1100 in the Allegro? With the popularity of the 1300 over the 1100, why bother putting the smaller engine into a heavier car? Or was it a ‘taxman’s special’ the rest of the world didn’t understand?
The O-series: O dear. Not what it should have been, to say the least. Having driven it in the Australian Morris 1500, I remember it as a rough, coarse unit which admittedly made that ADO16 shell fly (it finally had enough power!), but was nowhere near the standards being set elsewhere. While I can see why you’d put this engine into a heavier car for expediency’s sake, surely a properly developed 1500 would have been sufficient.
What a shame it was so heavy…
An O-series in a Morris 1500. That would be an E-series. Nobody in Australia had a good word for the 1500/Nomad – they had plenty bad ones instead. Yet, in principle it was a good idea, just needing proper development. Neither the parent nor its colonial satellite had the money or time for that sort of thing.
Here’s a pristine* example I found in Van Diemen’s Land:
I’m not certain whether the Australian E-series powered Marinas were similarly disliked. The engine was ill-suited to use in a rwd situation as the cylinder block was designed to take its strength from the transaxle casing. The Australian Marina installation compensated with a heavy and rigid cast aluminium sump. At least the E was usefully light, possibly around 50lb more than the A-series, rather than the 150lb extra load imposed by the B-series.
Peter – think you’re right about their engines and that got me thinking about the problems they had in designing them. I wonder if trying to make them suitable for transverse locations was always worth all the effort, given the compromises needed.
Re the 1100 engine, I believe that the previous model was launched as an 1100 and only got a 1300 engine later, so I think there was a lack of critical thinking – they just assumed that’s where the range would start. To be fair, the Golf had similarly small engines (albeit ones that performed well).
You asked about an Issigonis biography – I’ve read the one by Gillian Bardsley and thought it was done thoroughly and was even-handed.
https://www.wob.com/en-gb/books/gillian-bardsley/issigonis/9781840466874?gclid=EAIaIQobChMIueL14Imq_QIV82DmCh0Vyg3uEAQYAiABEgK5n_D_BwE#GOR002306669
Your description of this site being more like a group of friends made me smile. I think you’ve hit the nail on the head. Also, people on here have some real expertise and / or interest in dealing in facts, as well as having informed opinions. It’s very refreshing.
Charles: My understanding is that the 1100 Aggro was intended to cater to the section of the market who might previously have purchased a Minor 1000. It was not a lively car, nor it seems was it intended to be. Without it, there would have been a gaping hole in the model range, the Mini Clubman being the next step downwards … of course, what they really needed was a Supermini, but that took a while…
Sorry guys, I meant E-series!
Robertas, that’s the same colour as my aunt’s 1500 OD5 LP (one with the lot) sedan. Made me smile. She was used to driving her old A30, but the 1500 needed to be wound out a bit more in the gears. She was horrified, and said I’d break it! She lived in the country and mostly used it in and around town. I remember hearing comments about her husband’s 1100 being a better car. As you say, more development was needed.
The design thinking behind the E series is mind boggling.
They designed a brand new engine with siamesed bores from the beginning just to make sure it couldn’t be enlarged. This alone should have been enough to fire the one responsible for this decision.
Expansion was meant to happen by adding cylinder units for which there was no place under the bonnet of most cars equipped with the engine.
Then it was designed to only work with an in-sump gearbox at a time when it was clear that end-on transmissions were the way to go. Peugeot was in a similar situation when they redesigned their ‘suitcase’ engine to become the TU which features an horizontally split two layer crankcase with the lower part supporting the crankshaft bearings and stiffening the block.
And all this before you look at the A angled valves with the resulting strange combustion chamber geometry which is the exact opposite of a pentroof or wedge which recognisably were the future already then.
The VW Golf appeared with a small engine – 1,100 cc and 50 PS but it weighed only 700 kgs compared to the Allegro’s ~850 kgs. The 1,500 cc/70 PS Golf was fast enough for the German Parliament to express their concerns about VW’s recklessness of providing ordinary buyers with such race cars.
To sound a note of pedantry – I’m sure Eóin’s just testing us – the O-series arrived in July 1978 in the Princess 2, in 1.7 and 2.0 litre forms.
The Marina got the O-series later that year in 1.7 litre capacity only as the 2.0 was powerful and torquey enough to break that Triumph-developed gearbox. The Sherpa got both capacities.
The 1.7 O-series was unique in the B/O/M/T pantheon in being oversquare, and not having a 3½ inch (88.9mm) stroke dimension. The reason was rationalisation of components; only the crankshaft, con-rods and pistons varied between the two capacities.
At the time of the O-series launch, it was reported that it was “cost-effective down to 1.3 litres”, suggesting that it could be be cheaper to make than the A-series, which was around 50lb lighter but used expensive materials and components, and far more manual production processes.
I’ll put in a word for the Jonathan Wood Issigonis biography. The Bardsley book is better on the man and his “personal life”, the Wood book concentrates on the cars and the people Issigonis worked with. Both are essential reading.
A copy is on its way. Thank you, Robertas!
Great stuff once again. I may have read somewhere that the optimal size of the e series, going by the later engines developed from it, was 1.6?
There was zero chance of any triumph or rover based engines being used in the allegro too right? I ask because of the engines used in the Toledo.
“Optimal sizes” seem to vary through time. When the Maxi engine arrived, its undersquare 76.2 x 81.28mm proportions were considered to be unfashionable, as very oversquare short-stroke engines were the norm. The E-series’ small bore size dictated the knock-kneed valves and “pagoda” combustion chamber to achieve acceptable valve areas. Nowadays most engines are very undersquare, but the valve area matter is addressed by having four, rather than two per cylinder.
On AROnline, it’s said that the 1485 cc E series was “over-valved”, the 1748cc (76.2 x 95.75) was “under-valved” and the later 1598cc (76.2 x 87.6) R and S-series were just right. In any case, valve size is just one factor in creating an efficient engine, and was historically over-emphasised by British designers, to the neglect of porting and manifolding.
I think it’s probably just coincidence, but the 1.6 litre versions of the PSA TU and VW EA111 have very similar proportions to the S-series, as does the Tritec engine in the first generation MINI.
As DaveAR probably knows, the first 1.5 litre version of the VW EA827 in the 1972 Audi 80 B1 had 76.5 x 80.0mm proportions, almost identical to the 1485cc E-series. I don’t recall this being thought strange or regressive at the time. The difference between the BMC and VW engines was how much metal there was between the bores. VW had 11.5mm, the E-series family has somewhere around a meagre Imperial quarter-inch (6mm).
As for fitting other BLMC engines to the Allegro transmissions, the inflexibility of Issigonis’ “bunk-bed” powertrain would have made this very difficult – much more challenging than fabricating a simple a-daptor kit as Johnny Cash did with his one-piece-at-a time Cadillac, and the LC10 designers at BL later did with an end-on VW gearbox. More significant is production capacity; at its high point, well over 10,000 A-series engines were being produced per week, and E-series capacity (never remotely required) was 8500 per week. Standard-Triumph was a cottage industry by comparison.
@ Robertas oh wow I didn’t realise the sheer difference in production levels between the two! And I thought Triumph was a volume manufacturer too. Thanks for the info!
They eventually made a twin carb version of the e-series that had more go right? In 1750 capacity? Maybe the secret was to develop twin carb versions earlier, and on smaller capacity versions. Like a twin carb 1.3 or even 1.1 e series to help phase out the A? Ideally beginning this in ‘69, with no Marina to distract them.
I might be talking nonsense of course, I’m new to all this, but I’m just really curious as to if BL could have realistically worked with what BMC had left them.
Despite being a development of the regular in-sump transmission used in the Mini and ADO16, would a properly developed Jack Knight style 5-speed gearbox (with ability to feature 6-speeds) have been an adequate alternative to the rod-operated linkage Maxi/Allegro 5-speed gearbox provided it could be adapted to the E-series?
“…the whole gearbox underneath E-Series wasn’t really big enough. The distance between the shafts was too small, which meant the synchro cones were also too small.”
Question: Rather than raising the bonnet and scuttle height etc. of the Allegro, did they even consider tilting the powertrain instead, and would that also have opened a possibility to increase the size and robustness of the transmission so it could handle more power? and if not, then why not?
Indeed, gooddog. A good question, but I’m afraid the answer is beyond me.
Tilting back the powertrain may sound simple, but since the E series was designed to be mounted vertically, i imagine that you could not alter its mounting points without some sort of a bodge, which may or may not work. More so in this FWD application that the powertrain mountings had also to counteract the forces of the transmission too. Then, if you want to gain something meaningfull in height, the engine bay will be too long, pushing the scuttle back.
The thing is, i don’t understand why the E series was designed to be mated with a transmission underneath. This was a neccesity obviously in the Mini, due to width restrictions, but not really in the cars that followed. An end-on gearbox would not pose restrictions to the distance between the shafts, and there would have no need for intermediate transfer gears.
By the way, excellent write up Mr Doyle, i am thoroughly enjoying this.
Demetris: Thanks for this clarification and for the warm words. You are correct of course, insofar as the powertrain would, I would imagine, have needed to be mounted further forward. This of course would have put a lengthened Aggro directly into the sights of the Maxi, sizewise, and they couldn’t have that.
I have wondered about the transmission placement as well. With A-Series, one can see a logic for rationalisation purposes – even if it compromised the larger cars, but certainly for ADO17, and all of the E-Series cars, the logic escapes me. Orthodoxy perhaps? Dogma?
Mind you, if Peugeot could engineer a canted in line four with a sump-mounted gearbox..?
The only other drivetrain of comparable size with the gearbox in the sump was the one from Peugeot 204 to early 305 with up to 1.5 litres and 90 PS. It was tall and minimally tilted forward.
The closely related but much smaller ‘suitcase’ engine from the 104 with its 72 degree rearwards tilt shows the problems you get with a nearly horizontal engine. It takes up a lot of room longitudinally, there’s little room for a proper exhaust system and the inlet plumbing has to fit under the bonnet (in that case under the spare wheel). With an engine as large as the E this most probably wouldn’t have worked in the available space.
Building an engine for applications with different vertical orientations is not easy.
VW showed this when they converted their 1.9 litre diesel for installation in the Polo from a rearward tilt to forward pointing orientation. The main problem is the oil circulation, in particluar the channels draining the oil from the head back in the sump. These are located at an appropriate location in the head to make sure there’s always enough oil to lubricate the cams but to avoid flooding the head. When the head suddenly faces a different location all these drillings have to be relocated.
Water passages also have to be redesigned to avoid trapping air at the wrong places.
Look at the oil filter of Peugeot’s suitcase engine which is sitting on top of the engine. It is recommended to punch a hole in it to allow the oil to drain from it before removing it to avoid spilling the oil all over the engine. Now imagine the redesign work necessary for the near vertical installation after its transmogrification into the TU.
Eóin, now that i am thinking more on this, what you describe as a lengthened Allegro, could perhaps have been an exact materialisation of Mr Mann’s early wedge scetches, with a tilted back E-series fitted under a sloping bonnet… Now of course, the E-series was designed to be fitted vertically, unlike the 204 engine that was designed on purpose to be canted back, but perhaps it could work. I remember that the evolution of the Rover P6 4 cyl engine was canted in order to fit the 16 valve head, and it was essentially the same block that was fitted vertically in the P6. But i must say that all these ideas were probably too wild for the men that were taking the decisions at the time.
By the second half of 1960’s, orthodoxy in FWD powertrain design would dictate to look around at the solutions offered by other manufacturers, realise that the end-on gearbox layout offered by Autobianchi / FIAT was superior, and adopt it, like almost everybody else did at the time.
I’m not entirely sure you’re correct there, Demetris. The 204 engine was vertically mounted, as it was in the 304 I owned for a number of years. It was the 104 where the engine was canted rearwards, to the best of my recollection.
Frustratingly, BMC actually produced slanted versions of the B-series and the larger four cylinder Austin ‘Taxi’ engine, for use in the 250JU (‘U’ for underfloor) and EA vans. My recollection is that the angle was 55 degrees from vertical.
Here’s something else to throw on to the bonfire of possibilities. This is the transaxle of the automatic ADO17 introduced in March 1967:
Said to be mostly the work of Borg-Warner, who provided the Model 35TA transmission. Replace the torque convertor with a clutch, and the epicyclic geartrain with a manual gearbox and you have something far more flexible than Issigonis’ “bunk bed” configuration. Honda came up with something of the sort with the ill-starred 1300 saloon, first shown in late 1968.
Even more intriguing is that the 1979 front wheel drive GM X-cars had a near-identical automatic transmission layout to the ADO17 (and 71) although manual cars had an end-on gearbox, in the proper Giacosa fashion.
You are absolutely right Eóin. Somehow i have mixed up the Peugeot models.
Robertas, thanks for this. I was not aware of the BMC slanted B series engines. But somehow you reminded me of the stillborn Austin Ant, that was indeed fitted with a transverse A series powertrain tilted back, in order to allow for decent ground clearance.
From 1971 to 1973, Geoff Johnson’s engine design team were working on the H and K*-series engines, 1000-1300 cc OHC fours slanted at 15 to 30 degrees from vertical, still with an in-sump gearbox, and developed under Harry Webster’s watch as a “dedicated engine for Mini replacement”. Development would have started well before the Peugeot 104 was revealed in September 1972.
The designs were intriguing, but absolutely ‘cut to the bone’ with siamesed bores, simple bowl-in piston combustion chambers, and in the K’s case, three main bearings. There was no room for expansion, but they were still envisaged as replacements for the A-series in the Allegro. They were abandoned in the period of industrial paralysis which had beset BLMC by 1973 – nobody was prepared to sign off tooling costs, even though costings had demonstrated that the K-series* powertrain could be produced at a significantly lower cost than the A-series as used in the Mini and Allegro.
*Totally unrelated to the later Rover engine with the same codename.
The H/K Series were debatably said to have incorporated lessons previously learnt from the stillborn 1100-1300cc F-Series, what is particularly amusing is how later versions of the in-sump geared H/K-Series would eventually grow from being a dedicated engine (like the Imp engine effectively became unwittingly) to have the same 1100-1300cc displacement as the abandoned F-Series engine by the time it was cancelled.
Although the Graham Robson book on the A-Series which mentions the F-Series engine says there appears to be no link between it and the E-Series despite F following E, it is worth mentioning that the latter evolved from a 1300cc prototype with a belt-driven overhead camshaft before it was vetoed by Issigonis and bored out to to accommodate 3 inch pistons.
The F-Series was a similarly inchoate engine without a chosen destiny yet was an obvious contender to replace the A-Series and intended for both transverse and in-line installations. It was assumed belt-driven SOHC layout would be chosen and was meant encompass the 1100-1300cc capacity range, with prototypes having equal 74mm bore and stroke equating to 1273cc.
Sound familiar? Based on how similar the backgrounds are is it possible the E-Series actually sprung from what was later dubbed the F-Series, before significantly diverging from its original specifications as the request of Issigonis to become the conservative yet compromised engine that would later power the Nomad, Maxi, Allegro and Marina in 4-cylinder form?
If that is indeed the case and not completely baseless conjecture on my part drawn, then it is possible to see via the F-Series what the E-Series could have been.
There were also said to be several issues over the H/K-Series engines, although it is not clear how much of it was genuine and the other sour grapes by factions within BL. One being its slanted in-sump layout was not condensed at all, resulting in a bulky unusual shape with bits hanging off it. Another was Eric Bareham noting it would have been a challenge getting the engine down any transfer line, while Issigonis (who himself was biased towards the 9X engine) claimed it took up 5 inch more space than the A-Series.
The thought occurred to me when I saw the photo of the orange car with the bonnet open, because it appears there is empty space between the engine and the scuttle.
… and thanks very much Demetris and Eóin for the thoughtful replies.
Of course, with the levels of engine shunt seemingly exhibited by Aggro, I could envisage this proving a rather noisy experiment…
… and Robertas. The unwinding of this convoluted narrative has thus far been educative and interesting.
Another interesting loose end I noticed in [Part 4]. I was formerly mostly familiar with Dr. Moulton’s bicycle system, but I gained increased respect for him because although his family business was in the rubber industry, he seemed to have had no problem with foregoing Hydrolastic’s rubber springs in favor of a better solution. Like Issigonis he is sometimes painted as eccentric dogmatist, but I am beginning to see him more as a tenacious but flexible and open minded scientist.
It has also become clear to me from doing some outside research (e.g. two interviews with Spen King at AROnline) that perhaps tragically, King seemed to have disliked both Moulton and his ideas intensely. In addition to hobbling the development of Hydrogas, did this animosity lead to King’s seemingly reactionary and underwhelming work on the SD1, particularly its rear suspension; not up to the standard he himself had set with the P6? (To be continued, I hope…) Thanks to all who have participated thus far.
The later developments of the E, the R and the S, how were they overall? Just imagine they developed something like these 10+ years earlier, for the allegro. Again, imagine that they didn’t waste all that time and money on the Marina, and instead used those millions to help make the e series a decent unit. What a pity.
I have this imagine, may have said before, of a car with the looks of the Marina and the mechanicals of the allegro. That is to say, the FWD layout, the e series, the hydrolastic suspension. However the e series in said car has been developed into what we know came later with the S, but perhaps with a smaller capacity 1.3 too. Maybe even a 1.1? Released in 1971?
My thinking is, use what we know they definitely could do (because they actually did at one point or another) but earlier, and with better coordination.
I’ll try not to go off on a tangent and imagine this hypothetical car being used in a platform sharing role, with an Austin hatchback and triumph saloon lol
The R was basically a warmed-over problem-ridden E-Series converted to use a VW-sourced end-on gearbox.
The S while not without its problems was much better and agree it would have probably faired well had it appeared much earlier. More interested to know how minus the Crossflow head of the experimental 1.3 belt-driven SOHC engine that became the E, the belatedly S would go on to emulate a decade or more later.
S spinoffs that never reached production include a 1.4-litre, 4-valve version as well as diesel planned at one time for AR6 (the surviving prototype itself is said to be powered by a 1.6 S engine).
http://www.austinmemories.com/styled-66/index.html
Truth be told, there is much about the background of the E that is either unknown or unclear given it was originally a more sophisticated engine that became more conservative and compromised as it reached production due to Issigonis’s influence.
Not to mention the presence of a similar design to the original experimental 1.3 engine, if not the experimental engine itself under another name surviving until 1970/1971 before being cancelled.
Robertas, thanks for this. I was not aware of the BMC slanted B series engines. But somehow you reminded me of the stillborn Austin Ant, that was indeed fitted with a transverse A series powertrain tilted back, in order to allow for decent ground clearance.
No just out of contrariness, I’d contend that the SD1’s rear suspension was one of its best features – a triumph for Spen and Basho, and posthumously for Peter Wilks. It seems that a live axle was written into the P10 – later SD1 – specification from the outset, and in the late ’60s a P6 was fitted with a Vauxhall Ventora rear axle as proof of concept, with successful results.
The P6’s De Dion axle was in keeping with the progressive spirit of its time, but its actual benefit was questionable in a heavy, relatively low-powered saloon. Peter Wilks claimed that the feature was included “just to write its name in the specification of the car, even though it cost an extra £35”.
The Rover De Dion axle’s sliding splined joint turned out to be bothersome, and by the late ’60s all three engineers had matured, favouring well-tried solutions where they were out of sight, and keeping the innovation to the visible parts of the SD1.
@ gooddog, we are not strictly on topic here, but your mention of Spen King reminded me that i am also puzzled about him. While i respect his work on the P6 and the Range Rover (I am still a P6 owner), i have read that it was him that imposed the strange arrangement on the Metro hydragas: Front units completely independed, and the rear ones interconnected side to side. He might have not liked the system at all, but as it was proven through the years, hydrolastic and hydragas systems can deliver their potential only when each side is connected front to rear.
As for the SD1, i believe that he did his best within the limits imposed by the management. The SD1 had to sit below Jaguar, and probably there were just enough money to develop a simple car.
The Metro’s unconnected Hydragas was a terrible idea. Actually dangerous because of the risk of excess pressure building up in the displacers. Dr. Moulton soon obtained a Metro and interconnected the displacers, the benefit was immediately clear. As was often the way with The Firm, the lesson eventually sank in, with interconnection reinstated ten years too late in the R6.
The original Metro suspension was a bastardised travesty of Moulton’s principles; at the front there were conventional telescopic shock absorbers, and at the rear concentric steel coil springs to pre-load the rear Hydragas displacers. The nearest precedent I am aware of for the latter was the arrangement used for the Australian 1800 ‘ute’ which used torsion bars for the same purpose.
What I’d like to know is what Bob Knight was up to with his skunkworks Metro project? Who sanctioned him to carry out the work and did Moulton know about it?