128 vs Maxi Part 4: The Racehorse and the Donkey

We return to our analysis of the 50-year old Austin and Fiat contemporaries with a look at their engines. One was the work of a revered racing engine designer, the other was cobbled together by two capable engineers in the backrooms of Longbridge under the thumb of an unsympathetic boss with his own peculiar agenda.

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On paper a conservative design, the Maxi’s E series engine turns out to be downright odd in its execution. It evolved from a 1300cc prototype with a belt-driven overhead camshaft, one of many experimental designs being developed in the West Works at Longbridge. Long-serving engine designers Eric Bareham and Bill Appleby were handed the task of reworking the inchoate power unit into an engine suitable for BMC’s new mid-range car.

More capacity was needed, so it was bored out to accommodate 3 inch pistons, leaving no space for waterways between bores or any further outward expansion. Issigonis vetoed belt drive for the camshaft in favour of a traditional single-roller chain, on the reasonable grounds that belt technology was new and unproven at the time.

Morris and Wolseley had built overhead-cam engines in the inter-war era, and there was also – for a couple of difficult years – the MGA Twin Cam, designed under Gerald Palmer’s watch. However, the E series was BMC’s first volume-production OHC unit, and therefore an undertaking not to be taken lightly.

The end result was unadventurous and compromised – more like an improved version of the 1952 BMC A series than a challenge to the best European and Japanese designs of the time. There was limited opportunity taken of the freedoms offered by an OHC design; the valves are in-line, and directly actuated by the camshaft through inverted bucket tappets. The porting is reverse-flow. As all ports are on one side, there are restrictions on space and the layout imposed long inlet tracts, and much shorter tracts for the exhaust valves.

Most significantly, there is no convenient means of adjusting valve clearances. When required, adjustment is a camshaft-out and shimming-up job. By 1968 the British automotive world was familiar with OHC engines from Jaguar, Rover, and Hillman, and also aware of the laboriousness and potential for catastrophe the tappet adjusting process entailed.

GM took up the challenge, and Vauxhall’s 1967 OHC slant-four had a clever screw-adjustable wedge system for adjustment. The 1970 Ford OHC “Pinto” engine had finger rockers. BLMC merely claimed that “once set, the adjustment usually lasts the full period between top-end overhauls”.

Maxi engine cutaway. Source: Autocar

In 1485cc form, the engine was mildly undersquare (76.2mm x 81.28mm, or Imperially 3.0” x 3.2”) but far enough adrift of the prevailing short-stroke orthodoxy, to require something of an apologia. Edward Eves in Motor 24 April 1969 wrote:

“So much has been said about oversquare engines in past years that there is a tendency to regard any other type as out of date. However recent research in into objectionable exhaust emissions has shown that the small combustion chamber that goes with bore to stroke ratios of less than one gives low emissions, because of the small area of the quench surfaces.

It is significant that one of the latest engines to come from America (regrettably not named) is a long-stroke type. (Quench areas are the parts of the combustion chamber which stay cool enough during the combustion period to retain wet fuel, which is carried through into the exhaust). The Maxi head promises to be good in this respect because such areas are small and the head tends to run hot; low emissions mean that most of the charge is burnt, with consequential beneficial effect on fuel consumption.” 

All of which is as may be, but it does not explain why early E series engines needed 5 star (100 octane) petrol, despite a not particularly high 9.0:1 compression ratio.

The E series’ in-line valves are inclined from the vertical to maximise valve area, to create what is described as a “pagoda”combustion chamber. The effect of the angling of the valves is to distort the sectional shape of the traditional BMC-Weslake kidney shape chamber. It was claimed that the deepening at the ‘belly’ of the kidney promoted turbulence and improved combustion.

E series cross-section. Note the “knock-kneed” valves and “pagoda” combustion chamber. Source: Autocar

There is a feeling that BMC’s engineers Appleby and Bareham stuck with what they knew well and adapted it as necessary. The E series was reasonably efficient, but was never developed for high performance use.  Apart from the compromised top end design, the cylinder head was cast iron rather than aluminium alloy and the bottom end was weak – deliberately so, as it could depend on the gearbox in-sump casting for strength, allowing a reduction in weight and material use.

The E series’ five bearing cast-iron crankshaft had only four counterweights, and narrow bearings imposed by the closeness of the bore centres, and a Holset torsional vibration damper was fitted. The Issigonis-decreed need for a six cylinder E series restricted the engine’s width, needlessly as it turned out, as the assumption was that the six cylinder ADO17 would have a side-mounted radiator and engine-driven fan. In production a front-mounted radiator and electric fan were used for the transverse E6 installations.

Read between the lines and everywhere the story is of a compromised, cost-cut engine. The E series was not a disaster for BLMC, but in every aspect of its design it was a missed opportunity for a company which had not introduced an all-new engine since 1954.

Fiat 128 engine and transmission. Source: Autocar

With the celebrated engine designer Aurelio Lampredi as its parent, the 128 engine should have been outstandingly good, and for the most part it was.  The proviso is that it was very much built down to a price, albeit with considerable ingenuity.

Fiat 128 engine long section. Source: Fiat SpA

The first, 1116cc, variant was extraordinarily oversquare, with 80 x 55.5 bore and stroke dimensions. When more capacity was called for, the bore was further increased by 6mm to achieve 1290cc. The short stroke allowed an inherently strong five-bearing crankshaft, so all components could be produced by casting rather than the costlier forging process.

Fiat 128 crankshaft: Source: Fiat SpA

The design of the die-cast aluminium head is unambitious, but clever and appropriate.

Giacosa’s ‘123’ studies featured a three cylinder engine with a crossflow head with inclined valves operated through finger rockers by a centrally positioned overhead camshaft, an arrangement used by Maybach, NSU, Lloyd, BMW and Glas. Constrained by costs, Lampredi opted for in-line valves inclined at 18 degrees to the vertical, and thankfully parallel, unlike the “knock-kneed” arrangement of the Maxi.

Like Austin’s engine, the 128’s camshaft operates directly on inverted bucket tappets. The refinement Lampredi carried forward from the 124/125 twin cam engine is a simple means of adjusting tappet clearances with the camshaft in-situ by inserting hardened steel ‘coins’ into recesses at the top of the tappets, with only an inexpensive valve spring compressor tool and a modicum of skill required to perform the operation.

Source: Fiat SpA

The valve diameters of the 1116cc Fiat engine are only slightly smaller than those of the 1485cc E series.  (Inlet 1.5” / 1.42”, Exhaust 1.22” / 1.2”)

The 128 combustion chambers are wedge-shaped and compact in size, following the principles established with Fiat’s older ‘100’ engine. However the squish area – the “flat face “ of the circular area surrounding the combustion chamber – is actually slightly concave to improve turbulence and scouring.

Fiat 128 engine cross-section. Source: Autocar

There is similar attention to detail in inlet tracts, with a constant diameter of 25mm and a gentle curvature at the approach to the valve. A toothed belt drove the camshaft – Fiat had successful experience of this with Lampredi’s twin-cam 125 engine. Even in its first 55bhp form, the engine was highly regarded, the strongest criticism being of the level of engine noise. Perhaps it was a cultural matter – Italians like to hear their engines, northern Europeans want to suppress the cacophony.

If your engine’s not sitting on top of the gearbox, there’s room for a spare wheel in there. Source: Fiat SpA

Like much of the 128’s engineering, Lampredi’s engine appears simple, but reveals purity of principle and an ingenuity which made the end product both cost-efficient and a joyous experience.

“Joyous” is a word never applied to any aspect of the Austin Maxi, but its E series engine is at least worthy. Eric Bareham and Bill Appleby were highly experienced and able engineers, but were frustrated in their ambitions by their master’s peculiar agenda. It really does seem that Issigonis saw engines as another necessity which had to be packaged, no different to a battery or heater.

With more freedom, Bareham and Appleby could have made something far better, rather than an engine compromised from its very inception. To their credit they worked tirelessly to de-bug the E series in the pre-production period, and were largely successful – the engine was reported to have lower warranty repair costs than the A or B series units.

To their discredit – or that of Issigonis – the engine was a fleet manager’s nightmare, with no easy means of tappet adjustment, and its demand for five-star fuel. Both of these failings were easily avoidable, but somehow nobody bothered.

13 thoughts on “128 vs Maxi Part 4: The Racehorse and the Donkey”

  1. Was originally of the view that the E-Series (later S-Series) was a dog of an engine and was perplexed by the notion it was conceived to replace the A/B-Series and C-Series at once, it was only from a while ago when someone made a comparison between the E-Series and the Volkswagen EA827 that it all finally clicked though with the former having the potential to be more of a replacement for the B-Series and C-Series engines (with room for more if the EA827 was any indication since it formed the basis of 5-cylinder, 90-degree V6/V8/V10 and even the VR6 engines plus related derivatives if the VW Heritage blog is any indication).

    Am also interested in knowing how the EA827 and EA111 engines differed from each other aside from being known as the big block and small block engines respectively, since one seems to get the perhaps mistaken impression of the EA111 being a downscaled version of the EA827 as opposed to a completely unrelated engine and given the EA827’s comparison with the E-Series potentially gives a bit of an indication of a prospective small block replacement for the A-Series (at possibility significantly lower cost compared to other proposed A-Series replacement engine projects unless some unrealised relation exists between the E-Series and 9X engines).

    As for the 128 SOHC engine while being aware of its relation to the 130 V6, have been curious to know whether the engine was capable of growing beyond the Brazilian built 1839cc displacement to something closer to 2-litres despite the potential overlap with the Fiat 124 Series / Twin-Cam / Pratola Serra modular engines. The same goes to a lesser extent to the FIRE engine growing from 1368cc to something closer to 1600cc, beyond its origins as a joint-project between Fiat and PSA (prior to the latter opting to develop the X unit into the TU engine).

    1. The EA111 was the engine originally introduced with the Golf Mk1 1,100cc and Audi 50/VW Polo Mk1.
      It was available from 750cc (French market only) to 1,300 cc. It had a cross flow head, rockers and a sickle oil pump mounted to the end of the crankshaft.
      The EA827 was introduced with the Audi 80 Mk1 in 1,300cc and 1,500cc versions. It had a reverse flow head (sometimes with wedge shaped combustion chamber, sometimes with Heron type), bucket tappets and an intermediate shaft driving the Eaton oil pump and distributor via a skew gear and drive shaft. It had siamesed bores from 1,600cc upwards and got bigger by making the stroke ever longer.
      The EA111 was much smaller and lighter than the EA827 and it had differently spaced bore centres.
      When mounted longitudinally the EA827 was tilted to the right, the EA111 to the left. Mounted transversely, the EA827 was tilted backwards with intake and exhaust facing the bulkhead and EA111 was tilted forward with inlet facing the bulkhead and exhaust the radiator.

    2. Have read of the EA111 being enlarged to 1400-1600cc as well as spawning 3-cylinder and dieselized variants, also find it a bit curious that the 1300cc EA111 at one point displaced around 1272cc is vaguely similar to the 1275cc A-Series in terms of displacement and both being under-square (despite featuring different bore and stroke). Have to wonder whether it was within BMC’s ability (financial / management / union / etc problems notwithstanding) to develop a similar engine as the EA111 to replace the A-Series.

      Interested to know more about the French market only 750cc version of EA111, the closest thing seems to be the 34 hp 783cc version unique to the Swedish market.

      It is worth noting the early experimental EA827 engines was said to initially displace around 1200cc, while the lowest displacement 4-cylinder E-Series (besides a few later 3-cylinder experimental engines including a few pre-ECV3 units) displaced around 1160cc.

  2. Like many Italian engineers of that era, Lampredi had a background in aero engine design at Fiat.
    From this experience the most important characteristic of an engine for him was reliability.
    He considered every part in an engine as a potential source of failure and therefore reduced the parts count wherever possible.
    Lampredi also had a thoroughly scientific approach to engine design and he strongly believed that every aspect of an engine should be designed by calculation, leaving no room for guesswork. In this he was the absolute opposite of Gioacchino Colombo who was a strong believer in using rules of thumb and empirical engine design. The time they were both in Ferrari’s engine department must have been interesting.

    1. The Autocar launch issue specification states “compression ratio 9.0 to 1. Min. octane rating 100”.

      The high octane requirement goes otherwise unremarked, but I’ve seen it reported in other sources – there was surprise that car like the Maxi should demand the same grade of fuel as an E-Type. I suspect the issue was resolved in later production. The 1500’s compression ratio does not seem to have changed in the first four years, but the power output had dropped a couple of bhp by 1973, possibly down to use of DIN rather British net measurement standards.

      There’s no attribution in the article quoted in Austin Memories. It could have come from Vicar’s typewriter, but the author refers to his “six foot six frame”; I never encountered the great man in person, but the only physical attribute widely noted was that he was believed to have “hollow legs”.

  3. Thanks for that. While the British engine conforms to my prejudices about British engineering, the Fiat engine plays against type. It strikes me as a rather rigorously conceived unit where intelligence has defeated cost. The UK engine seems like a poor idea moderated, a classic conserative fudge. It sort of works but it need not have been so. Where are the national stereotypes now? I have no feel for Italian engines and the only British engine I can name is the Ingenium series, not an engine family without problems.

  4. Love the illustrations. And the commentary. Presumably the second cutaway of the 128 engine which shows siamesed bores is the 1290 cc version, because the first showing gearbox and suspension shows water around the bores. These days nearly all the high pressure allie die-cast engines are siamesed bores of course, or they’d do an uncontrolled fandango without the closed upper deck sand casting can accomodate.

    The Maxi engine. Dear oh dear. Long-skirted pistons and four ring pack, weird stresses on the camlobe surfaces for the splayed valves, and a chuffer stroke on the 1750. Never heard about the long stroke for emissions claim – these days a 20% longer stroke than bore is used for thermal efficiency. Poor old E engine, no money for decent design, and even given it was almost 50 years ago, it looks ancient. The only new US engine of the era that was undersquare was the 89 by 92 mm Chevrolet Vega engine, despite BL’s claim. The Vega engine was, of course, an even worse piece of junk than the Maxi engine, probably far worse. I can replay in my mind’s eye the desperate sound it made plugging along.

    Really enjoyable reading. Would love to hear your take on the later BL K Series engine. On the surface of it, you wonder what they were thinking. Having been allied with Honda for years, you’d have thought more nous would have rubbed off, given all the Honda engines they installed and probably had zero trouble with in Rovers and Triumphs. But I’d like to hear your opinion.

    1. The original 1,100cc to 1,400cc K series was a closed deck design with location for the wet liners provided at their top. It got converted to open top with liners located at the bottom when it got enlarged to 1,800cc and only this version suffered from permanent head gasket troubles (and sinking liners).
      What were they thinking?
      They needed a larger engine and didn’t want to pay Honda (very expensive) royalties for using their engines and the only available engine was the K which got enlarged far beyond its design target.

    2. Bill – thanks for the encouragement and enlightening comments. You have rumbled me on the long section of the 128 engine – it was taken from a 128 Coupe brochure, so it is an 86mm bore version, although pedants may note that the 1116cc engine was also available in the Coupe.

      The identity of the engine referred to in Edward Eves’ “one of the latest engines to come from America is a long-stroke type” comment remains a mystery. My knowledge of US engines of the period is limited, but I don’t think it can be the Vega engine as that car was not launched until June 1970, and the Maxi article was published in April 1969. Could it be the Ford 250 straight six? That’s hardly a new engine, rather one that was stretched upwards as there was no room to go any further outwards.

      The Vega engine, by every account, had an appalling reputation; one of GM’s many deranged diversions which make the company oddly lovable to automotive flaneurs. I doubt if the consumers or shareholders took such a whimsical view.

      Why on earth didn’t Chevrolet use a well-proven biggish four from their European portfolio – either the Opel CIH or the Vauxhall OHC slant-four? I suppose ‘unit costs’ was the answer. The US alumin(i)um lobby was having one of its periodic cheaper-than-iron pushes, and GM swallowed it whole, paying the price in warranty costs and reputational damage.

      Which brings me neatly to the K series. There’s an anniversary coming up – the K series arrived with the R8 Rover 200 on 11 October 1989. I’m sure Mr. Editor Kearne has the date in his marbled ledger. Whether the call will come my way is a matter for his discretion.

    3. Chevrolet did have a potentially viable alternative to the existing Vega engine called the aluminum SOHC L10 engine, with of the prototype engines being used in the XP-898 one-off (being the lone surviving example of the engine) and putting out about 111 hp.

      The generally accepted story of the SOHC L10 engine is the cost of the aluminum head was greater than the iron head version and a decision to go with only one engine type rather than two to save investment. Had it been approved it would have given higher performance than the iron-head engine, without its differential expansion head gasket problems.

    4. I remember an Opel manager stating in a Seventies’ interview that GM’s small block V8 was cheaper to make than Opel’s CIH engine and that the latter already had very favourable production costs…

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