115 replies to this topic

[Mite]

While the A-Series was a remarkable engine, would have to vehemently disagree on the notion it would have been pointless to update / evolve the engine further than what was already done let alone concede the do-nothing approach was the best one to take. The 1300 Triumph engine is irrelevant prior to the formation of BL, beyond possessing odd valuable feature like an 8-port head that belong on an updated A-Series.

 

The existing A-Series engines inability to grow to 1.6-litres handicapped a number of critical models that could have otherwise been remedied by a linear low/mid-range A-Series successor akin to the 1000-1600cc Nissan A / Series 2 E engines. Such an engine would have still been in essence an A-Series with some carry over or interchangeability from the existing unit, yet minus most of the limitations apart from say for example sharing the existing A-Series engine’s reliable power limit of around 120-130 hp in road-going applications*.  

 

It would have butterflied away the necessity of various stillborn A-Series successors (including the V4/V6 blind alley), been a lot cheaper to produce compared to embracing a clean sheet design like the underdeveloped E-Series (in reality a compromised mid/high-range engine that Issigonis / BMC pretended could realistically replace 3 engine families at once) and would have opened up more options for various applications in cars like the Mini, ADO16, Midget, etc.

 

*-) Around 120-130 hp seems to be the absolute reliable limit for the 1275cc A-Series in tuned road-going form give or take a few hp, yet have read of the MG Metro Turbo originally being capable of up to 130 hp before being significantly detuned to preserve the life of the gearbox.

 

The 115 hp Nissan E15ET engine used in the Nissan Cherry 1.5 Turbo (and a distant relation to the A-Series) would demonstrate even the most potent of a hypothetical updated A-Series or linear A-Series successor displacing up to 1.6-litres would not have needed to reach the 120-130 hp limit, as it could also serve a similar role to the 1.5 E-Series, 1.6 R/S-Series and 1.7 O-Series (as well as a much lighter alternative to the 1.6 B-Series) in non-performance applications.

Edited by Mite, 24 July 2019 - 04:14 AM.

[DeadSquare]

Ford had the problem with their small engine that it was a really old side-valve which made even the 1950' A-series seem modern.
Rootes didn't really have a small engine. So the 105E and Imp both had modern engines whilst BMC had the A which was acceptable at the time.
The failure to design and develop an A series replacement was a function of the inability of BMC to rationalise their entire engine range in the way that, say, Ford did so well.
In hindsight it is regrettable, but then the entire history of BMC/BLMC is most unfortunate with the reasons being a variety of factors.

 

 

" Old Harry Ford took some rubber and a can,

 

nailed it to a board, and the damn thing ran"

[DeadSquare]

While the A-Series was a remarkable engine, would have to vehemently disagree on the notion it would have been pointless to update / evolve the engine further than what was already done let alone concede the do-nothing approach was the best one to take. The 1300 Triumph engine is irrelevant prior to the formation of BL, beyond possessing odd valuable feature like an 8-port head that belong on an updated A-Series.

 

The existing A-Series engines inability to grow to 1.6-litres handicapped a number of critical models that could have otherwise been remedied by a linear low/mid-range A-Series successor akin to the 1000-1600cc Nissan A / Series 2 E engines. Such an engine would have still been in essence an A-Series with some carry over or interchangeability from the existing unit, yet minus most of the limitations apart from say for example sharing the existing A-Series engine’s reliable power limit of around 120-130 hp in road-going applications*.  

 

It would have butterflied away the necessity of various stillborn A-Series successors (including the V4/V6 blind alley), been a lot cheaper to produce compared to embracing a clean sheet design like the underdeveloped E-Series (in reality a compromised mid/high-range engine that Issigonis / BMC pretended could realistically replace 3 engine families at once) and would have opened up more options for various applications in cars like the Mini, ADO16, Midget, etc.

 

*-) Around 120-130 hp seems to be the absolute reliable limit for the 1275cc A-Series in tuned road-going form give or take a few hp, yet have read of the MG Metro Turbo originally being capable of up to 130 hp before being significantly detuned to preserve the life of the gearbox.

 

The 115 hp Nissan E15ET engine used in the Nissan Cherry 1.5 Turbo (and a distant relation to the A-Series) would demonstrate even the most potent of a hypothetical updated A-Series or linear A-Series successor displacing up to 1.6-litres would not have needed to reach the 120-130 hp limit, as it could also serve a similar role to the 1.5 E-Series, 1.6 R/S-Series and 1.7 O-Series (as well as a much lighter alternative to the 1.6 B-Series) in non-performance applications.

 

 

Tooling a tin sump pan for a host of Nissans is peanuts.

 

Once Issigonis committed  BMC to an expensive alloy one, aka the gearbox, two of the engine dimensions were set in stone.

 

BMC did explore the third dimension.  I once helped take a deliberately destroyed SOHC alloy block off an auto 5 speed Mini gearbox.  It was about 2 litres, and I will always remember looking down the bore when the head was removed;  it was like looking down a well.

 

My I politely point out to you, that many of your "If only cylinder heads" are available, not from BMC, but BMW.

[Mite]

Am aware of Mini's with BMW sourced heads, etc.

 

Not suggesting BMC could have developed a production Twin-Cam A-Series or linear A-Series successor with Twin-Cams, at best such an engine would only be for limited-run homologation models as opposed to full production engines (with or without the assistance of people like Harry Mundy, etc). One only needs to see the underdeveloped 1.6 B-Series Twin-Cam, which to be fair could have been salvaged had Gerald Palmer not been fired during its development.

 

Rather at most a linear A-Series successor would be an alloy-headed SOHC engine (which may either retain the A-Series's 5-port arrangement or adopt a 7/8-port one) that like the existing A-Series is capable of being turbocharged, a production NA 1596cc linear A-Series successor would hypothetically put out at most around 105+ hp (using the 84 hp 1275cc A-OHC as a rough guide) while a turbocharged 1596cc linear A-Series successor would hypothetically put out at most around 118+ hp (using both the 94 hp 1275 A+ Turbo as well as a 1597cc version of the 115 hp 1487cc Nissan E Turbo as rough guides).

 

Such an engine is well within BMC's capability to develop (and for BL if it still happens to further develop it), even if Issigonis has his own overly ambitious ideas with the underdeveloped E-Series (along with a mixed record when it comes to developing engines e.g. Morris Flat-4s, Alvis V8, 9X, etc), a linear A-Series successor would not overlap too much with a properly developed E-Series / S-Series especially in cars like the Metro (possibly even limited-run Minis), Midget or Midget successor (e.g. ADO34, EX234, Healey WAEC, etc) where a E-Series or S-series would likely be too tall. Unlike the E-Series or S-Series, it is likely a linear A-Series successor like the O-Series would not have any issues complying with emissions standards in order to be sold in markets like the US, Australia, etc.

Edited by Mite, 25 July 2019 - 12:28 AM.

[Spider]

I think one would be best off taking a clean sheet of paper and going from there.

 

I'm not suggesting the A Series is a poor engine, it was a wonderful engine for what it was and when it was designed, taking in to account an outdated Government Taxation as well, resulting it most capacities it was produced in being under-square.

 

To gain a improved engine, I feel the an over-square design would be better, not just from any HP gains (which cubic inch for cubic inch there likely would be) but also from smoothness, economy, possibly manufacturing costs, engine life, just about all aspects.

 

In this regards, I'd suggest looking to the likes of some of the smaller Toyota Engines for layout and basic features and working from there. I think a diesel would have had some appeal too, but I think (?) in the UK there's now a move against them?

 

I think too, the Gearbox would also benefit from a 'start from scratch' redesign too. Ideally, it would still need to be retained under the engine, but separate it from the Engine Oil.

[Mite]

If an updated A-Series or linear A-Series successor carries over elements from both the South African and the A-OHC engine, than it would indeed feature short-stroke 1000-1100cc units initially via a common 70.6mm bore with scope for further boring out to develop short-stroke 1300-1600cc engines beginning with a 76mm+ bore for a short-stroke 1300cc to square 1400cc and so on.

 

Am also intrigued by a hypothetical Perkins developed dieselized or turbodiesel 1275cc A-Series / 1300-1600cc linear A-Series successor (followed later by smaller analogues of the Rover L/G-Series or equivalent Renault K-Type), at least a better attempt than the earlier 948cc diesel used in the BMC Mini Tractor (and at one point supposedly planned for commercial Mini derivatives despite there not yet being any concrete evidence of such). The lower 1300cc displacement version would challenge the 1301-1367cc Fiat 124 Series diesels (e.g. Panda/Uno), 1272-1398cc Volkswagen EA111 diesels (e.g. Polo), 993cc Daihatsu C-Series diesel (e.g. Charade/Innocenti Mini) and later 1360-1527cc PSA TUD diesel (Citroen AX). While likely challengers to the larger displacement 1500-1600cc versions would be the 1471-1588cc Volkswagen EA827 diesels (e.g. Golf), 1608cc Ford LT diesel (e.g. Fiesta/Escort), 1488-1686cc Isuzu E diesel (Nova/Astra) and 1453cc Toyota N diesel (e.g. Starlet/Corolla) engines.  

 

The gearbox layout is another matter entirely, while ideally a 5-speed in-sump manual and 5-speed AP automatic could have been developed BMC would have been better off quickly adopting the end-on layout and implementing it for an updated Mini and ADO16/ADO22/Allegro or Maxi. Alec Issigonis himself looked at such a layout with an experimental FWD Morris Minor prototype before moving to Alvis, only for Fiat’s Dante Giacosa to succeed with bringing the end-on layout to production with the Autobianchi Primula followed by the Autobianchi A112, Fiat 128 and Fiat 127.

 

Curiously during the development of the original Minki prototype, it is said the engineers looked at whether a Maestro A-Series with end-on gearbox could fit only to realise it was too tight a fit in the current Mini's dimensions due to the A-Series engine being roughly equivalent to a K-Series three and a half cylinder engine in length. However if the above is any indication in theory an end-on gearbox layout mated to an A-Series or linear A-Series successor should theoretically have been possible in an updated Mini or Mini successor with similar dimensions to the Minki-II prototype (e.g. extra 50mm or 2-inches in width / length), which would also have had the side-effect of potentially making common / relatively straight-forward Mini engine swaps like the Rover K-Series, Nissan CG/CR and Suzuki G less of a tight fit.

Edited by Mite, 25 July 2019 - 03:19 AM.

[Spider]

While an end on Gearbox would be desirable for a large variety of reasons, I suggested keeping the Gearbox under the engine - for the Mini - as going end on along with a bigger bore engine, starts to get the whole package rather long, which, in the case of the Mini, could well impact on the available space for the wheels to move in to for steering.

 

All the engine conversions I've seen suffer from this, and really, for it's given size, the turning circle of the Mini in it's standard form, was not as good as many would expect. Any further erosion of this wouldn't be in the best direction.

 

As I see it, considering this aspect, the whole package can't be any wider than the front rail of the front subframe, though, back from that, it can spread out a little.

[Mite]

Not sure to what extent an existing Mini's package could accept a larger bore engine beyond the 70.6mm 1275cc A-Series, however the extra 50mm width / length in the Minki-II prototype did allow for the 1.4-litre 16v K-Series and end-on gearbox to slot in which featured a 75mm bore x 79mm stroke.

 

Which would suggest a hypothetical Mini II with Minki-II dimensions could theoretically accept a linear A-Series successor featuring similar bore x stroke to the 75mm x 90mm 1590cc Suzuki G16 or the 76mm x 88mm 1597cc Nissan E16, that while not a short-stroke engine in 1.6-litre form would still be able to form the basis of smaller short-stroke to square engines in 1000-1400cc form.

Edited by Mite, 25 July 2019 - 07:11 AM.

[mini13]

how far do you go before you might as wwell start from scratch though...  as the saying goes you cant polish a turd, not that the A series is a turd, but you somtimes you cant turn somthing into somthing else it was never meant to be.

[DeadSquare]

The heart and soul of the 1959 Mini was a sump with gears in it, and it still is.

 

It is that, that gave it its dimensions, whereas the 1100 and the 1800 could have had an end on gearbox

 

It wasn't the first front wheel drive, nor the last transverse engine.

 

A Mini is a Mini because the engine sits on top of the gearbox;  remove that element, and a Mini is just another car.

 

Sitting the A series on that gearbox , stifled almost any evolution of the A series block after 1957.

 

Any "What ifs" like an extra 2"  had to be a different engine, it could not be an evolution of the A series block.

 

The A series cylinder head could and did evolve, but wasn't adopted because the improvements warranted a different block.

 

It follows that the A series was doomed not to evolve, not least because it didn't need to, it was just so darned good.

[Ethel]

How much was it that the Min got wider between prototype and production? Along with losing some cc's to finish at 848?

 

Sitting the engine on the gearbox was a fundamental decision for the compact design. Maybe it isn't essential, but if you were to have an end on transmission it would be infinitely easier with a different engine, like a modern 3 cylinder. 

[DeadSquare]

"The Mini getting wider", is something of which I have only heard in recent years, and I'm inclined to doubt it. 

 

Issigonis did add 2" to the Morris Minor 'the night before production', but that probably means that he was hardly likely to make the same design error ten years later, although he did consider using 1/2 an A series which could have resulted in a narrower car, but I don't think it ever got off the drawing board.

 

The more I think about "conversions" , the more strongly I feel that anything which does not incorporate a Mini gearbox, is such a bastard that it should not be called or classed as a Mini by true enthusiasts.

[r3k1355]

 if I recall, the development of the A+ cost a claimed 35 million pounds and this was over the period 1977 - 1979 !! Serious money. 

 

Given the timeframe in question it's not hard to see where the money went, straight into the pockets of overpaid, useless management.

Edited by r3k1355, 25 July 2019 - 10:58 AM.

[mab01uk]

The more I think about "conversions" , the more strongly I feel that anything which does not incorporate a Mini gearbox, is such a bastard that it should not be called or classed as a Mini by true enthusiasts.

 

I have to agree, the drop gear and transmission whine is all part of the Minis appeal, probably also why the 1970's Mini racers with Ford and Imp engines grafted onto a Mini gearbox also fascinated me at the time. Not to mention 'Landcrab 1800' and Maxi 1750 units with similar gearbox in sump transplants into Minis back then. A modern Vauxhall or Honda Vtec transplant with end on gearbox just does not have the same appeal or enough 'classic Mini' DNA for me.....

Edited by mab01uk, 25 July 2019 - 11:42 AM.

[mab01uk]

How much was it that the Min got wider between prototype and production? Along with losing some cc's to finish at 848?

 

Sitting the engine on the gearbox was a fundamental decision for the compact design. Maybe it isn't essential, but if you were to have an end on transmission it would be infinitely easier with a different engine, like a modern 3 cylinder. 

 

It was originally 948cc but looks about the same body width in these photos:-

http://www.theminifo...k-daniels-1993/