Facts and Figures | Engines

A-series engine

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The A-series engine did service in a variety of cars for almost 50 years, during which time it was available in a bewildering variety of capacities and states of tune.


A hard act to follow


The 1275cc engine of the MkII Mini-Cooper S.

The A-Series engine was certainly a case of the 'British Curate's egg' - good in places. In fact, that is not quite true: the A-Series was a fine engine. Of course, by the time of the launch of the Austin Metro in 1980, great play was made by the British press about the fact that here they had a new car, which truly competitive and (in the context of the small/medium BL range of cars), as good news as it was, it was still powered by an engine that first saw service in the Austin A30 some 30 years previously. Of course, to make this criticism was to miss the point entirely.

British Leyland had expended much time and effort on the task of replacing the A-Series engine, but the trouble was that it was capable of delivering fantastic fuel consumption figures thanks in no small part to its excellent torque characteristics and thermal efficiency. Because of this, the A-Series became a victim of its own success: why produce a replacement, when there was doubt that anything new that was produced would be any better to drive?

Discounting the remarkable 9X power unit, the first serious attempt to replace the A-Series engine was the anticipated motive power for the ADO74 programme, instigated in 1972. This engine, dubbed the K-Series engine was an OHC design, which had been designed to be canted backwards some 70 degrees in order to improve the packaging of the new car. The signs were promising - and although when bench tested, the power output was significantly higher than the standard A-Series could manage, it still did not produce the same impressive torque figures. Nevertheless, the engine was cancelled, not because it would have proven to be an unworthy successor to the A-Series engine, but simply because it was part of an ambitious development programme that BLMC could ill-afford.


The experimental K-series (left) and A-series (right) OHC engines, now preserved at the Heritage Motor Centre at Gaydon.

Signs that the company were becoming keen on developing the (by-now) long in the tooth A-Series engine resurfaced in 1975, when a new OHC cylinder head was produced. The intention was for introduction in the ADO74's replacement, the ADO88, but there emerged some problems. Like the K-Series before it, this engine produced more power than the older engine, yet did not offer a big enough advantage over it to warrant the expense of a full development programme. Not only that, but following the Ryder Report of 1975, the finances of the company were now controlled by the Government, and as a result, all non-essential spending was placed under minute scrutiny. The decision to call a halt to the A-OHC programme, therefore, was an easy one to make.

From the ashes of A-OHC did emerge the A-Plus programme, which involved a modest upgrading of the engine, which facilitated a small rise in maximum power output (without affecting its torque characteristics) and a lengthening of main service intervals.

As a result, the A-Series engine enjoyed something of an Indian Summer being, as it was, the power unit for the Austin Metro during the whole of the 1980s. It also saw service in the Austin Maestro/Montego and without the disadvantage of the somewhat flawed transmission-in-sump layout; it would prove to be a reliable and strong performer in these cars. Eventually, an engine called K-Series did replace the A-Plus, but it was not the same engine as that from 1972 - and it took a radical change in thinking to produce something significantly better - and this would not arrive until 1989. Had the A-Series not been so eminently suitable for the task in hand - reasonably powerful, economical and compact, the Mini would probably not been the success it was and the Metro would probably never have come into being in the form it did.

The Mini remained A-Series powered all through its life, starting out with just 34bhp in 1959, and ending its days with the 63bhp, twin-point injection unit developed in 1997 by Rover engineer Mike Theaker.


Specifications & applications

CapacityBoreStrokeMax. PowerMax. Torque Applications
803cc58.0mm76.2mm28bhp @ 4400rpm40lb ft @ 2200rpm1952-56: Austin A30
30bhp @ 4800rpm40lb ft @ 2400rpm1952-56: Morris Minor Series II
848cc62.9mm68.26mm33bhp @ 5300rpm44lb ft @ 2900rpm1969-80: Mini 850 / Mini City
34bhp @ 5500rpm44lb ft @ 2900rpm1959-69: Austin Seven / Austin/Morris Mini
1961-62: Riley Elf / Wolseley Hornet
1964-68: Austin Mini-Moke
948cc62.9mm76.2mm34bhp @ 4750rpm50lb ft @ 2000rpm1956-62: Austin A35
1958-61: Austin A40 Farina
37bhp @ 4750rpm50lb ft @ 2500rpm1956-62: Morris Minor 1000
37bhp @ 5000rpm50lb ft @ 2500rpm1961-62: Austin A40 Farina MkII
43bhp @ 5200rpm52lb ft @ 3300rpm1958-61: Austin-Healey Sprite
46bhp @ 5500rpm53lb ft @ 3000rpm1961-64: Austin-Healey Sprite MkII
1961-64: MG Midget
970cc70.6mm61.91mm65bhp @ 6500rpm55lb ft @ 3500rpm1964-67: Austin/Morris Mini Cooper S
997cc62.43mm81.28mm55bhp @ 6000rpm54lb ft @ 3600rpm1961-64: Austin/Morris Mini Cooper
998cc64.58mm76.2mm38bhp @ 5250rpm52lb ft @ 2700rpm1962-69: Riley Elf / Wolseley Hornet
1967-80: (Austin/Morris) Mini
1969-75: Mini Clubman
41bhp @ 4850rpm52lb ft @ 2750rpm1969-80: Mini Clubman (auto)
55bhp @ 5800rpm57lb ft @ 3000rpm1964-69: Austin/Morris Mini Cooper
A+ specification39bhp @ 4750rpm52lb ft @ 2000rpm1980-82: Mini 1000 / City / HL
40bhp @ 5000rpm50lb ft @ 2500rpm1982-88: Mini HLE / City E / Mayfair
41bhp @ 5400rpm51lb ft @ 2700rpm1980-90: Austin Metro
42bhp @ 5250rpm58lb ft @ 2600rpm1988-92: Mini City / Mayfair
44bhp @ 5250rpm52lb ft @ 3000rpm1980-82: Austin Allegro
1071cc70.6mm68.26mm70bhp @ 6000rpm62lb ft @ 4500rpm1963-64: Austin/Morris Mini Cooper S
1098cc64.58mm83.72mm45bhp @ 5250rpm55lb ft @ 2900rpm1975-80: Austin Allegro
45bhp @ 5250rpm56lb ft @ 2700rpm1975-80: Mini Clubman
1979-80: Mini 1100 Special
48bhp @ 5100rpm60lb ft @ 2500rpm1962-71: Morris 1100 / Morris Minor 1000
1963-74: Austin 1100
49bhp @ 5250rpm60lb ft @ 2450rpm1973-75: Austin Allegro
55bhp @ 5500rpm61lb ft @ 2500rpm1962-68: MG 1100
1963-67: Vanden Plas Princess 1100
1965-68: Riley Kestrel / Wolseley 1100
56bhp @ 5500rpm62lb ft @ 3250rpm1962-64: Austin-Healey Sprite MkII
1962-64: MG Midget
59bhp @ 5750rpm65lb ft @ 3500rpm1964-66: Austin-Healey Sprite MkIII
1964-66: MG Midget MkII
1275cc70.6mm81.28mm54bhp @ 5300rpm65lb ft @ 2550rpm1974-80: Mini 1275GT
58bhp @ 5250rpm69lb ft @ 3500rpm1967:      MG 1275 / Riley 1275
1967:      Wolseley 1275
1967:      Vanden Plas Princess 1275
58bhp @ 5250rpm69lb ft @ 3000rpm1967-74: Austin 1300
1967-73: Morris 1300
1967-68: MG 1300 / Wolseley 1300
1967-68: Riley Kestrel 1300
1967-68: Vanden Plas Princess 1300
59bhp @ 5300rpm65lb ft @ 2550rpm1969-74: Mini 1275GT
59bhp @ 5300rpm69lb ft @ 3000rpm1973-80: Austin Allegro
60bhp @ 5250rpm69lb ft @ 2500rpm1968-71: Austin America (auto)
1971-80: Morris Marina
65bhp @ 5750rpm71lb ft @ 3000rpm1968:      MG 1300 / Riley Kestrel 1300
1968-73: Wolseley 1300*
1968-74: Vanden Plas Princess 1300*
* Automatic models retained 58bhp unit (see above)
65bhp @ 6000rpm72lb ft @ 3000rpm1966-74: MG Midget MkIII
1966-70: Austin-Healey Sprite MkIV
1971:      Austin Sprite
70bhp @ 6000rpm74lb ft @ 3250rpm1969-74: Austin 1300GT
1969-71: Morris 1300GT
70bhp @ 6000rpm77lb ft @ 3000rpm1968-73: MG 1300 MkII
1968-69: Riley Kestrel 1300 / Riley 1300
76bhp @ 5800rpm79lb ft @ 3000rpm1964-71: (Austin/Morris) Mini Cooper S
A+ specification50bhp @ 5000rpm66lb ft @ 2600rpm1992-2000: Mini Sprite / Mayfair
61bhp @ 5550rpm61lb ft @ 3000rpm1990-91: Mini Cooper
61bhp @ 5300rpm69lb ft @ 2950rpm1980-84: Morris Ital
62bhp @ 5600rpm72lb ft @ 3200rpm1980-82: Austin Allegro
63bhp @ 5700rpm70lb ft @ 3900rpm1991-1996: Mini Cooper 1.3i / Cabriolet
63bhp @ 5500rpm70lb ft @ 3000rpm1997-2000: Mini Cooper 1.3i (TPi)
63bhp @ 5650rpm72lb ft @ 3100rpm1980-90: Austin Metro
64bhp @ 5500rpm73lb ft @ 3500rpm1983-85: Austin Maestro HLE
68bhp @ 5800rpm75lb ft @ 3500rpm1983-93: Austin Maestro
68bhp @ 5600rpm75lb ft @ 3500rpm1984-89: Austin Montego
72bhp @ 6000rpm73lb ft @ 4000rpm1982-89: MG Metro
73bhp @ 6000rpm73lb ft @ 4000rpm1989-90: Metro GTa
77bhp @ 5800rpm80lb ft @ 3000rpm1991-2000: Mini Cooper S 1.3i
78bhp @ 6000rpm78lb ft @ 3250rpm1990-91: Mini Cooper S
93bhp @ 6130rpm85lb ft @ 2650rpm1983-89: MG Metro Turbo
96bhp @ 6130rpm1989-90: Mini ERA Turbo

John Cooper Garages

During the 1990s Mini Cooper revival, John Cooper Garages offered a number of factory-approved "Cooper S" and "Cooper Si" upgrades to the standard Coopers. The conversions came with a full Rover warranty, and could initially be fitted by any franchised Rover dealer.

TypeMax. Power TypeMax. Power
S pack (carb.)77bhp 3rd Si pack (SPi)86bhp
1st Si pack (SPi)77bhp 1997 Si pack (TPi)85bhp @ 5500rpm
2nd Si pack (SPi)82bhp 1999 Si pack (TPi)90bhp @ 6000rpm


Gallery

A-OHC Picture supplied by Ian Nicholls - car owned by Jerry Evans


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Thanks to David Jacobs for his assistance in checking and contributing to the data section on this page, and to Ian Nicholls for the John Cooper Garages information.


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Related pages:

·B series engine
·K series engine
·Rover V8 engine

Facts and Figures | Engines