|Facts and Figures | Engines|
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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 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
|Capacity||Bore||Stroke||Max. Power||Max. Torque||Applications|
|803cc||58.0mm||76.2mm||28bhp @ 4400rpm||40lb ft @ 2200rpm||1952-56: Austin A30|
|30bhp @ 4800rpm||40lb ft @ 2400rpm||1952-56: Morris Minor Series II|
|848cc||62.9mm||68.26mm||33bhp @ 5300rpm||44lb ft @ 2900rpm||1969-80: Mini 850 / Mini City|
|34bhp @ 5500rpm||44lb ft @ 2900rpm||1959-69: Austin Seven / Austin/Morris Mini|
1961-62: Riley Elf / Wolseley Hornet
1964-68: Austin Mini-Moke
|948cc||62.9mm||76.2mm||34bhp @ 4750rpm||50lb ft @ 2000rpm||1956-62: Austin A35|
1958-61: Austin A40 Farina
|37bhp @ 4750rpm||50lb ft @ 2500rpm||1956-62: Morris Minor 1000|
|37bhp @ 5000rpm||50lb ft @ 2500rpm||1961-62: Austin A40 Farina MkII|
|43bhp @ 5200rpm||52lb ft @ 3300rpm||1958-61: Austin-Healey Sprite|
|46bhp @ 5500rpm||53lb ft @ 3000rpm||1961-64: Austin-Healey Sprite MkII|
1961-64: MG Midget
|970cc||70.6mm||61.91mm||65bhp @ 6500rpm||55lb ft @ 3500rpm||1964-67: Austin/Morris Mini Cooper S|
|997cc||62.43mm||81.28mm||55bhp @ 6000rpm||54lb ft @ 3600rpm||1961-64: Austin/Morris Mini Cooper|
|998cc||64.58mm||76.2mm||38bhp @ 5250rpm||52lb ft @ 2700rpm||1962-69: Riley Elf / Wolseley Hornet|
1967-80: (Austin/Morris) Mini
1969-75: Mini Clubman
|41bhp @ 4850rpm||52lb ft @ 2750rpm||1969-80: Mini Clubman (auto)|
|55bhp @ 5800rpm||57lb ft @ 3000rpm||1964-69: Austin/Morris Mini Cooper|
|A+ specification||39bhp @ 4750rpm||52lb ft @ 2000rpm||1980-82: Mini 1000 / City / HL|
|40bhp @ 5000rpm||50lb ft @ 2500rpm||1982-88: Mini HLE / City E / Mayfair|
|41bhp @ 5400rpm||51lb ft @ 2700rpm||1980-90: Austin Metro|
|42bhp @ 5250rpm||58lb ft @ 2600rpm||1988-92: Mini City / Mayfair|
|44bhp @ 5250rpm||52lb ft @ 3000rpm||1980-82: Austin Allegro|
|1071cc||70.6mm||68.26mm||70bhp @ 6000rpm||62lb ft @ 4500rpm||1963-64: Austin/Morris Mini Cooper S|
|1098cc||64.58mm||83.72mm||45bhp @ 5250rpm||55lb ft @ 2900rpm||1975-80: Austin Allegro|
|45bhp @ 5250rpm||56lb ft @ 2700rpm||1975-80: Mini Clubman|
1979-80: Mini 1100 Special
|48bhp @ 5100rpm||60lb ft @ 2500rpm||1962-71: Morris 1100 / Morris Minor 1000|
1963-74: Austin 1100
|49bhp @ 5250rpm||60lb ft @ 2450rpm||1973-75: Austin Allegro|
|55bhp @ 5500rpm||61lb ft @ 2500rpm||1962-68: MG 1100|
1963-67: Vanden Plas Princess 1100
1965-68: Riley Kestrel / Wolseley 1100
|56bhp @ 5500rpm||62lb ft @ 3250rpm||1962-64: Austin-Healey Sprite MkII|
1962-64: MG Midget
|59bhp @ 5750rpm||65lb ft @ 3500rpm||1964-66: Austin-Healey Sprite MkIII|
1964-66: MG Midget MkII
|1275cc||70.6mm||81.28mm||54bhp @ 5300rpm||65lb ft @ 2550rpm||1974-80: Mini 1275GT|
|58bhp @ 5250rpm||69lb ft @ 3500rpm||1967: MG 1275 / Riley 1275|
1967: Wolseley 1275
1967: Vanden Plas Princess 1275
|58bhp @ 5250rpm||69lb ft @ 3000rpm||1967-74: Austin 1300|
1967-73: Morris 1300
1967-68: MG 1300 / Wolseley 1300
1967-68: Riley Kestrel 1300
1967-68: Vanden Plas Princess 1300
|59bhp @ 5300rpm||65lb ft @ 2550rpm||1969-74: Mini 1275GT|
|59bhp @ 5300rpm||69lb ft @ 3000rpm||1973-80: Austin Allegro|
|60bhp @ 5250rpm||69lb ft @ 2500rpm||1968-71: Austin America (auto)|
1971-80: Morris Marina
|65bhp @ 5750rpm||71lb ft @ 3000rpm||1968: MG 1300 / Riley Kestrel 1300|
1968-73: Wolseley 1300*
1968-74: Vanden Plas Princess 1300*
* Automatic models retained 58bhp unit (see above)
|65bhp @ 6000rpm||72lb ft @ 3000rpm||1966-74: MG Midget MkIII|
1966-70: Austin-Healey Sprite MkIV
1971: Austin Sprite
|70bhp @ 6000rpm||74lb ft @ 3250rpm||1969-74: Austin 1300GT|
1969-71: Morris 1300GT
|70bhp @ 6000rpm||77lb ft @ 3000rpm||1968-73: MG 1300 MkII|
1968-69: Riley Kestrel 1300 / Riley 1300
|76bhp @ 5800rpm||79lb ft @ 3000rpm||1964-71: (Austin/Morris) Mini Cooper S|
|A+ specification||50bhp @ 5000rpm||66lb ft @ 2600rpm||1992-2000: Mini Sprite / Mayfair|
|61bhp @ 5550rpm||61lb ft @ 3000rpm||1990-91: Mini Cooper|
|61bhp @ 5300rpm||69lb ft @ 2950rpm||1980-84: Morris Ital|
|62bhp @ 5600rpm||72lb ft @ 3200rpm||1980-82: Austin Allegro|
|63bhp @ 5700rpm||70lb ft @ 3900rpm||1991-1996: Mini Cooper 1.3i / Cabriolet|
|63bhp @ 5500rpm||70lb ft @ 3000rpm||1997-2000: Mini Cooper 1.3i (TPi)|
|63bhp @ 5650rpm||72lb ft @ 3100rpm||1980-90: Austin Metro|
|64bhp @ 5500rpm||73lb ft @ 3500rpm||1983-85: Austin Maestro HLE|
|68bhp @ 5800rpm||75lb ft @ 3500rpm||1983-93: Austin Maestro|
|68bhp @ 5600rpm||75lb ft @ 3500rpm||1984-89: Austin Montego|
|72bhp @ 6000rpm||73lb ft @ 4000rpm||1982-89: MG Metro|
|73bhp @ 6000rpm||73lb ft @ 4000rpm||1989-90: Metro GTa|
|77bhp @ 5800rpm||80lb ft @ 3000rpm||1991-2000: Mini Cooper S 1.3i|
|78bhp @ 6000rpm||78lb ft @ 3250rpm||1990-91: Mini Cooper S|
|93bhp @ 6130rpm||85lb ft @ 2650rpm||1983-89: MG Metro Turbo|
|96bhp @ 6130rpm||1989-90: 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.
|Type||Max. Power||Type||Max. 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|
Cutaway drawing of the 848cc A-series complete with transmission-in-sump, as it first appeared in the 1959 Mini.
The 998cc Mini-Cooper engine, in situ.
The A-Plus version of the A-series engine laid bare. The revised engine represented an investment of £30m, and would see service in the Mini, Allegro, Ital, Maestro and Montego, as well as the Metro for which it was originally developed.
Cutaway drawing of the A-series with end-on gearbox, as used in the Austin-Healey Sprite and MG Midget from 1961 until 1974.
The longitudinally-mounted, 948cc A-series, as fitted to the MkI MG Midget.
The OHC A-Series engine, as produced by BL Technology: The engine is one of only four OHC A-series engines built by BL Technology during the 1970s, one of the others is in Gaydon (Pictured at the top of the page). The head is aluminium with 36.5mm inlet and 30mm exhaust valves.
A-OHC Picture supplied by Ian Nicholls - car owned by Jerry Evans
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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|Facts and Figures | Engines|