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 thirty 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.
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 (Austin Design Office) 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 DIESEL: 1965-1968: BMC MINI-Tractor 9/16 diesel
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
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
...more BMC A-Series engine
Austin Motor Company's small straight-4 automobile engine, the A-Series, is one of the most common in the world. Launched in 1951 with the Austin A30, production lasted into the 1990s in the Mini.
The A-Series design was licensed by Nissan of Japan, along with other Austin designs. That company quickly began modifying the A-Series, and it became the basis for many of the following Nissan engines.
* 1 A versions
* 1.1 803
* 1.2 948
* 1.3 848
* 1.4 997
* 1.5 998
* 1.6 1098
* 1.7 1071
* 1.8 970
* 1.9 1275
* 2 A-Plus versions
* 2.1 998 Plus
* 2.2 1275 Plus
* 2.3 1275 Turbo
* 2.4 1275 TPi
* 3 References
The original A-Series engine displaced just 803 cm and was used in the A30 and Morris Minor. It had an undersquare 58 mm bore and 76.2 mm stroke. This engine was produced from 1952 through 1956.
* 19521956 Austin A30, 28 hp (21 kW) at 4400 rpm and 40 ft·lbf (54 N·m) at 2200 rpm
* 19521956 Morris Minor Series II, 30 hp (22 kW) at 4800 rpm and 40 ft·lbf (54 N·m) at 2400 rpm
1956 saw a displacement increase, to 948 cm. This was accomplished by boring the block out to 62.9 mm while retaining the original 76.2 mm stroke. It was produced through 1964.
* 19561962 Austin A35, 34 hp (25 kW) at 4750 rpm and 50 ft·lbf (68 N·m) at 2000 rpm
* 19561962 Morris Minor 1000, 37 hp (28 kW) at 4750 rpm and 50 ft·lbf (68 N·m) at 2500 rpm
* 19581961 Austin A40 Farina, 34 hp (25 kW) at 4750 rpm and 50 ft·lbf (68 N·m) at 2000 rpm
* 19581961 Austin-Healey Sprite, 43 hp (32 kW) at 5200 rpm and 52 ft·lbf (71 N·m) at 3300 rpm
* 19611962 Austin A40 Farina MkII, 37 hp (28 kW) at 5000 rpm and 50 ft·lbf (68 N·m) at 2500 rpm
* 19611964 Austin-Healey Sprite MkII, 46 hp (34 kW) at 5500 rpm and 53 ft·lbf (72 N·m) at 3000 rpm
* 19611964 MG Midget, 46 hp (34 kW) at 5500 rpm and 53 ft·lbf (72 N·m) at 3000 rpm
The 62.9 mm bore was retained for 1959's 848 cm Mini version. This displacement was reached by dropping the stroke to 68.26 mm. This engine was produced through 1980 for the Mini, when the A+ version supplanted it.
* 19591969 Austin Seven/Austin Mini/Morris Mini, 34 hp (25 kW) at 5500 rpm and 44 ft·lbf (60 N·m) at 2900 rpm
* 19611962 Riley Elf/Wolseley Hornet, 34 hp (25 kW) at 5500 rpm and 44 ft·lbf (60 N·m) at 2900 rpm
* 19641968 Austin Mini-Moke, 34 hp (25 kW) at 5500 rpm and 44 ft·lbf (60 N·m) at 2900 rpm
* 19691980 Mini 850/City, 33 hp (25 kW) at 5300 rpm and 44 ft·lbf (60 N·m) at 2900 rpm
The one-off 997 cm version for the Mini Cooper used a smaller 62.43 mm bore and longer 81.28 mm stroke. It was produced from 1961 through 1964.
* 19611964 Austin/Morris Mini Cooper, 55 hp (41 kW) at 6000 rpm and 54 ft·lbf (73 N·m) at 3600 rpm
The Mini also got a 998 cm version. This was similar to the 948 in that it had the same 76.2 mm stroke but was bored out slightly to 64.58 mm. It was produced from 1962 through 1980.
* 19621969 Riley Elf/Wolseley Hornet, 38 hp (28 kW) at 5250 rpm and 52 ft·lbf (71 N·m) at 2700 rpm
* 19641969 Austin/Morris Mini Cooper, 55 hp (41 kW) at 5800 rpm and 57 ft·lbf (77 N·m) at 3000 rpm
* 19671980 Austin/Morris Mini, 38 hp (28 kW) at 5250 rpm and 52 ft·lbf (71 N·m) at 2700 rpm
* 19691975 Mini Clubman, 38 hp (28 kW) at 5250 rpm and 52 ft·lbf (71 N·m) at 2700 rpm
* 19691980 Mini Clubman (automatic), 41 hp (31 kW) at 4850 rpm and 52 ft·lbf (71 N·m) at 2750 rpm
The 1.1 L (1098 cm) version was produced for the larger BMC saloons. It was a stroked (to 83.72 mm) version of the 998 previously used in the Riley Elf and Wolseley Hornet. It was produced from 1962 through 1980.
* 19621967 Austin A40 Farina, 48 hp (36 kW) at 5100 rpm and 60 ft·lbf (81 N·m) at 2500 rpm
* 19621971 Morris 1100/Morris Minor 1000, 48 hp (36 kW) at 5100 rpm and 60 ft·lbf (81 N·m) at 2500 rpm
* 19621968 MG 1100, 55 hp (41 kW) at 5500 rpm and 61 ft·lbf (83 N·m) at 2500 rpm
* 19621964 Austin-Healey Sprite MkII, 56 hp (42 kW) at 5500 rpm and 62 ft·lbf (84 N·m) at 3250 rpm
* 19621964 MG Midget, 56 hp (42 kW) at 5500 rpm and 62 ft·lbf (84 N·m) at 3250 rpm
* 19631974 Austin 1100, 48 hp (36 kW) at 5100 rpm and 60 ft·lbf (81 N·m) at 2500 rpm
* 19631967 Vanden Plas Princess 1100, 55 hp (41 kW) at 5500 rpm and 61 ft·lbf (83 N·m) at 2500 rpm
* 19641966 Austin-Healey Sprite MkIII, 59 hp (44 kW) at 5750 rpm and 65 ft·lbf (88 N·m) at 3500 rpm
* 19641966 MG Midget MkII, 59 hp (44 kW) at 5750 rpm and 65 ft·lbf (88 N·m) at 3500 rpm
* 19651968 Riley Kestrel/Wolseley 1100, 55 hp (41 kW) at 5500 rpm and 61 ft·lbf (83 N·m) at 2500 rpm
* 19731975 Austin Allegro, 49 hp (37 kW) at 5250 rpm and 60 ft·lbf (81 N·m) at 2450 rpm
* 19751980 Austin Allegro, 45 hp (34 kW) at 5250 rpm and 55 ft·lbf (75 N·m) at 2900 rpm
* 19751980 Mini Clubman, 45 hp (34 kW) at 5250 rpm and 56 ft·lbf (76 N·m) at 2700 rpm
* 19791980 Mini 1100 Special, 45 hp (34 kW) at 5250 rpm and 56 ft·lbf (76 N·m) at 2700 rpm
The 1071 cm version was another one-off, this time for the Mini Cooper S. It used a new 70.6 mm bore size and the 68.26 mm stroke from the 848. It was only produced in 1963 and 1964.
* 19631964 Austin/Morris Mini Cooper S, 70 hp (52 kW) at 6000 rpm and 62 ft·lbf (84 N·m) at 4500 rpm
The Mini Cooper S next moved on to a 970 cm version. It had the same 70.6 mm bore as the 1071 cm Cooper S but used a shorter 61.91 mm stroke. It was produced from 1964 through 1967.
* 19641967 Austin/Morris Mini Cooper S, 65 hp (48 kW) at 6500 rpm and 55 ft·lbf (75 N·m) at 3500 rpm
The largest A-Series engine displaced 1.3 L (1275 cm). It used the 70.6 mm bore from the Mini Cooper S versions but the 81.28 mm stroke from the plain Mini Cooper. It was produced from 1964 through 1980 when it was replaced by an A+ version.
* 19641971 Austin/Morris Mini Cooper S, 76 hp (57 kW) at 5800 rpm and 79 ft·lbf (107 N·m) at 3000 rpm
* 19661970 Austin-Healey Sprite MkIV, 65 hp (48 kW) at 6000 rpm and 72 ft·lbf (98 N·m) at 3000 rpm
* 19661974 MG Midget MkIII, 65 hp (48 kW) at 6000 rpm and 72 ft·lbf (98 N·m) at 3000 rpm
* 19671968 MG 1300/Wolseley 1300, 58 hp (43 kW) at 5250 rpm and 69 ft·lbf (94 N·m) at 3000 rpm
* 19671968 Riley Kestrel 1300, 58 hp (43 kW) at 5250 rpm and 69 ft·lbf (94 N·m) at 3000 rpm
* 19671968 Vanden Plas Princess 1300, 58 hp (43 kW) at 5250 rpm and 69 ft·lbf (94 N·m) at 3000 rpm
* 19671973 Morris 1300, 58 hp (43 kW) at 5250 rpm and 69 ft·lbf (94 N·m) at 3000 rpm
* 19671974 Austin 1300, 58 hp (43 kW) at 5250 rpm and 69 ft·lbf (94 N·m) at 3000 rpm
* 1967 MG 1275/Riley 1275, 58 hp (43 kW) at 5250 rpm and 69 ft·lbf (94 N·m) at 3500 rpm
* 1967 Wolseley 1275, 58 hp (43 kW) at 5250 rpm and 69 ft·lbf (94 N·m) at 3500 rpm
* 1967 Vanden Plas Princess 1275, 58 hp (43 kW) at 5250 rpm and 69 ft·lbf (94 N·m) at 3500 rpm
* 19681969 Riley Kestrel 1300/Riley 1300, 70 hp (52 kW) at 6000 rpm and 77 ft·lbf (104 N·m) at 3000 rpm
* 19681971 Austin America (automatic), 60 hp (45 kW) at 5250 rpm and 69 ft·lbf (94 N·m) at 2500 rpm
* 19681973 Wolseley 1300 (manual), 65 hp (48 kW) at 5750 rpm and 71 ft·lbf (96 N·m) at 3000 rpm
* 19681973 MG 1300 MkII, 70 hp (52 kW) at 6000 rpm and 77 ft·lbf (104 N·m) at 3000 rpm
* 19681974 Vanden Plas Princess 1300 (manual), 65 hp (48 kW) at 5750 rpm and 71 ft·lbf (96 N·m) at 3000 rpm
* 1968 MG 1300/Riley Kestrel 1300, 65 hp (48 kW) at 5750 rpm and 71 ft·lbf (96 N·m) at 3000 rpm
* 19691971 Morris 1300GT, 70 hp (52 kW) at 6000 rpm and 74 ft·lbf (100 N·m) at 3250 rpm
* 19691974 Mini 1275GT, 59 hp (44 kW) at 5300 rpm and 65 ft·lbf (88 N·m) at 2550 rpm
* 19691974 Austin 1300GT, 70 hp (52 kW) at 6000 rpm and 74 ft·lbf (100 N·m) at 3250 rpm
* 19711980 Morris Marina, 60 hp (45 kW) at 5250 rpm and 69 ft·lbf (94 N·m) at 2500 rpm
* 1971 Austin Sprite, 65 hp (48 kW) at 6000 rpm and 72 ft·lbf (98 N·m) at 3000 rpm
* 19731980 Austin Allegro, 59 hp (44 kW) at 5300 rpm and 69 ft·lbf (94 N·m) at 3000 rpm
* 19741980 Mini 1275GT, 54 hp (40 kW) at 5300 rpm and 65 ft·lbf (88 N·m) at 2550 rpm
British Leyland was keen to update the old A-Series design in the 1970s. However, attempts at replacement, including an aborted early-70s K-Series and an OHC version of the A-Series, ended in failure. The little A-Series just worked too well. So the "A-Plus" was born. By tweaking the engine, BL engineers were able to extract more power without affecting torque. Some engine components were also replaced with more-reliable designs.
The A-Plus version of the 998 cm motor was produced from 1980 through 1992.
* 19801982 Mini 1000/City/HL, 39 hp (29 kW) at 4750 rpm and 52 ft·lbf (71 N·m) at 2000 rpm
* 19801982 Austin Allegro, 44 hp (33 kW) at 5250 rpm and 52 ft·lbf (71 N·m) at 3000 rpm
* 19801990 Austin Metro, 41 hp (31 kW) at 5400 rpm and 51 ft·lbf (69 N·m) at 2700 rpm
* 19821988 Mini HLE/City E/Mayfair, 40 hp (30 kW) at 5000 rpm and 50 ft·lbf (68 N·m) at 2500 rpm
* 19881992 Mini City/Mayfair, 42 hp (31 kW) at 5250 rpm and 58 ft·lbf (79 N·m) at 2600 rpm
The big 1.3 L (1275 cm) engine was also given the "A-Plus" treatment. This lasted from 1980 through 2000, making it the last of the A-Series line.
* 19801982 Austin Allegro, 62 hp (46 kW) at 5600 rpm and 72 ft·lbf (98 N·m) at 3200 rpm
* 19801984 Morris Ital, 61 hp (46 kW) at 5300 rpm and 69 ft·lbf (94 N·m) at 2950 rpm
* 19801990 Austin Metro, 63 hp (47 kW) at 5650 rpm and 72 ft·lbf (98 N·m) at 3100 rpm
* 19821989 MG Metro, 72 hp (54 kW) at 6000 rpm and 73 ft·lbf (99 N·m) at 4000 rpm
* 19831985 Austin Maestro HLE, 64 hp (48 kW) at 5500 rpm and 73 ft·lbf (99 N·m) at 3500 rpm
* 19831993 Austin Maestro, 68 hp (51 kW) at 5800 rpm and 75 ft·lbf (102 N·m) at 3500 rpm
* 19841989 Austin Montego, 68 hp (51 kW) at 5600 rpm and 75 ft·lbf (102 N·m) at 3500 rpm
* 19891990 MG Metro GTa, 73 hp (54 kW) at 6000 rpm and 73 ft·lbf (99 N·m) at 4000 rpm
* 19901991 Mini Cooper, 61 hp (46 kW) at 5550 rpm and 61 ft·lbf (83 N·m) at 3000 rpm
* 19901991 Mini Cooper S, 78 hp (58 kW) at 6000 rpm and 78 ft·lbf (106 N·m) at 3250 rpm
* 19911996 Mini Cooper 1.3i/Cabriolet, 63 hp (47 kW) at 5700 rpm and 70 ft·lbf (95 N·m) at 3900 rpm
* 19911996 Mini Cooper S 1.3i, 77 hp (57 kW) at 5800 rpm and 80 ft·lbf (108 N·m) at 3000 rpm
* 19921996 Mini Sprite/Mayfair, 50 hp (37 kW) at 5000 rpm and 66 ft·lbf (89 N·m) at 2600 rpm
The 1.3 L (1275 cm) engine was turbocharged, producing the highest-output A-Series variant at 96 hp (72 kW) in the 1989 Mini ERA Turbo. Turbo versions lasted from 1983 through 1990.
* 19831989 MG Metro Turbo, 93 hp (69 kW) at 6130 rpm and 85 ft·lbf (115 N·m) at 2650 rpm
* 19891990 Mini ERA Turbo, 96 hp (72 kW) at 6130 rpm
A special "twin-port injection" version of the 1.3 L (1275 cm) engine was developed by Rover engineer, Mike Theaker. It was the last A-Series variant, produced from 1997 through 2000.
* 19972000 Mini Cooper 1.3i (TPi), 63 hp (47 kW) at 5500 rpm and 70 ft·lbf (95 N·m) at 3000 rpm
The B-Series engine started out as a humble
1.2-litre unit that powered the Austin A40 Devon. Over time, it
was developed - and developed - and developed.
After the end of World War II, Austin and Morris continued to rely on pre-war engines for their mid-range family cars. Out of the two companies, it was Austin that managed to introduce an entirely new engine for its A40 Devon model. This engine displaced 1.2-litres (65.5mm x 88.9mm bore/stroke), produced 39bhp at 4300rpm and was an overhead valve design. Morris, on the other hand, continued to rely on the side-valve solution for its engine, as used in the Issigonis designed Morris-Cowley.
By the time of BMC's formation in 1952, this was still very much the engine situation, and it meant that the company had a choice between the Austin A40 engine and the 1477cc Morris unit.
Given the relative merits of the two engines, and the Austin-biased management in the new organisation, it comes as no surprise that the Austin unit was adopted as the new engine to power all of the company's cars in the mid-range.
Logically enough, it was subsequently dubbed the B-Series, and it proved to be significant in BMC's history because its features defined the style for all of BMC's later engines. Included in this list would be the location of its electrical equipment and the induction/exhaust complex on opposite sides of the engine block. Also, the pushrods passed through passages on the induction side of thecylinder head in order to avoid the use of pressed-in tubes passing across the plug cavity. The crankshaft had three main bearings and the connecting rods were split diagonally.
In 1954, the first three-box BMC saloon was launched; the Austin Cambridge, which employed the B-Series engine in 1.2-litre guise, as well as a newly-enlarged 1489cc version. The uprated B was produced by a simple process of "boring-out" to 73mm. The power output of this version of the engine was 50bhp, which was produced at 4400rpm. This engine was also used in the Morris Oxford series II and the MG ZA Magnette, although the MG was treated to a twin-carburettor set-up, which boosted power to 60bhp at 4600rpm.
It was with the engineers at MG that the B-Series went through further development in order to release more power - eventually resulting in the 68bhp version that powered the 1956 MGA.
In 1961, the B-Series had been further evolved: the B's engine block was redesigned in order to accomodate newly-siamesed bores, thus enabling the bore to be increased to 75.4mm. This increased the capacity to 1622cc and it was possible - with tuning - for it to produce 83bhp. This extra power was produced at 5600rpm, and these higher rev limits were possible thanks to the use of Vandervell VP3 in the main bearings. Among the other changes were improved valves, pistons and rings. It was not until the following year that a "cooking" version of the B found its way into the Farina saloons... they made do with a more realistic 61bhp at 4500rpm.
Further development of the B-Series led to a 1798cc version of the engine, which - in three-bearing form - first saw the light of day in the MGB. The bore centres remained the same as the original 1.2-litre A40 Devon engine, but the bore measurements grew out to 80.3mm. In time for the launch of the ADO17 in 1964, the three-bearing crankshaft was replaced by a five-bearing item in the interests of increased smoothness, and this new set-up resulted in a power output of 84bhp (gross) at 5300rpm. Development continued as far as the addition of twin-carburettors, a set-up developed with the help of Daniel Richmond, which was used in the Austin and Morris 1800S versions.
By the early 1970s, it became clear that the B-Series needed to be replaced with a new unit that would be able to meet with upcoming US emissions regulations. The B-Series was by then, well established in 1800cc capacity alone, and was used in the front wheel drive 1800 models as well as the rear wheel drive Marina and MGB. Because a development programme to replace it never got far off the ground, the engineers at Abingdon worked hard on an OHC version of the engine, which would meet and exceed the forthcoming emissions regulations. This was the nearest thing to a replacement in the pipeline, and when it became clear that the ADO17's replacement would need a de-smogged engine, the new car, which subsequently evolved into the Princess was designed to use the OHC version of the B-Series engine.
Given that the two engines were initially going to be physically very similar, the development of the newer engine would not need to be accelerated to meet the new car. And that led to the MG engine being adopted as the corporate replacement for the B-Series, which resulted in further and wider ranging changes. The result was the O-Series; an engine that started out as being related to the B-Series, but became more of a case of the Irish hammer - two new handles, three new heads, but the same hammer!
In 1978, the O-Series was launched in 1.7- and 2-litre form, and over time, that evolved into the O2-Series in 1985 (seen in the Maestro and Montego EFi); a prelude to the technically interesting M16 engine of 1986; which shared the O2's engine block. The M16 was used in the Rover 820, and in 1992, it took on it's final metamorphosis, into the T16...
...more BMC B-Series engine
The BMC B-Series was a straight-4 automobile engine family created as a larger alternative to the company's A-Series.. Displacements ranged from 1.2 L, 1.6 L, and even 2.4 L.
The engine was of conventional construction with a one piece crankcase and cylinder block in cast iron with cylinder head also usually in cast iron. The sump was made from pressed steel. Early engines used a three bearing crankshaft but later engines used five bearings. On all except the rare twin overhead camshaft variant the camshaft, which was chain driven and mounted low in the block, operated the overhead valves via pushrods and rocker arms. The two inlet ports in the non-crossflow cylinder head were shared between cylinders 1 + 2 and 3 + 4 and the three exhaust ports between cylinder 1, 2 + 3 and 4. Valve clearance was adjustable by screws on the rocker arms with access to the tappets by two side covers on the engine block, this feature being a probable hang over from side valve engine design.
* 1 Engine numbering
* 1.1 Early numbering system
* 1.2 1957-1970 numbering system
* 1.3 1970 onwards numbering system
* 2 Automobiles using the B-Series
* 3 Engine Types
* 3.1 1.2 litre engines
* 3.2 1.5 litre engines
* 3.3 Twin-Cam engines
* 3.4 1.6 litre engines
* 3.5 1.6 litre Mark II engines
* 3.6 1.8 litre engines
* 3.7 2.5 litre engines
* 4 External references
There were two series of engine numbers used as BMC changed the system at the end of 1956.
Early numbering system
Numbers were in the style BP15GB plus a serial number where:
* B = B series engine
* P = Pushrod
* 15 = capacity
* G = MG (for full list see Later numbering system below)
* The final letter is the version of the engine.
1957-1970 numbering system
Numbers were in the style 15GB-U-H plus a serial number where:
* 15 = capacity
* G = MG (other letters were: A = Austin, B = Industrial, H = Miscellaneous, J = Commercial, M = Morris, R = Riley, V = Vanden Plas and W = Wolseley )
* B = B series engine
* U = Central gear change (other letters were: A = Automatic, M = Manumatic clutch, N = Column change, O = Overdrive and P = Police)
* H = High compression (alternatively L = Low compression)
1970 onwards numbering system
Numbers were simplified to 16 V plus a serial number where 16 represents the capacity and V = vertical ie in-line engine with rear wheel drive and H = Horizontal ie transverse engine with front wheel drive. There was sometimes a country indicator after the first part of the code eg 18V-Z was use for some United States(except California) MGB engines.
Automobiles using the B-Series
Examples of cars using a version of the B series engine:
* Alexis GT
* Austin A40 Dorset, Devon and Somerset
* Austin 1800/Morris 1800
* Austin A50 Cambridge
* Austin A55 Cambridge
* Austin A60 Cambridge
* Austin Lancer (Australian model based on Riley 1.5 and Wolseley 1500)
* Elva Courier
* Gilbern GT
* Ginetta G11
* Hindustan Ambassador
* Lanchester Sprite
* Lotus Eight
* Morris Cowley/Morris Oxford
* Morris Marina
* Morris Major (Australian model based on Riley 1.5 and Wolseley 1500)
* Metropolitan 1500
* MG A
* MG B
* MG Magnette
* Ogle 1.5
* Princess 1800
* Riley 1.5
* Riley 4/68 and 4/72
* Rochdale Olympic
* TVR Grantura
* TVR Vixen
* Wolseley 15/50 and 15/60
* Wolseley 1500
* Wolseley 16/60
* Wolseley 18/85
1.2 litre engines
The 1200 cc was the first version of the engine and appeared in the 1947 Austin A40 Devon and Dorset. The bore was 65.5 mm and the stroke 89 mm. The maximum power output was 40 bhp at 4300 rpm. Later versions of the engine differed significantly from this early version.
* 1947-1952 Austin A40 Devon and Dorset
* 1952-1954 Austin A40 Somerset
* Austin A40 Cambridge 1954-1956
* 1954-1962 Nash Metropolitan 1200
* Massey-Harris Combine Harvester
1.5 litre engines
B-Series 1500 engine in a Nash Metropolitan
The 1.5 L (1489 cc) version was first used in 1953 in the MG Magnette ZA in twin carburettor version and in 1954 in the Morris Oxford and Austin Cambridge. In 1957 it was used in the original MGA. Output in twin carburettor form was 68 to 72 bhp (51 to 54 kW) and 55 bhp with a single carburettor. Bore was 73.025 mm (2.9 in) and stroke was 89 mm (3.5 in).
There was also a diesel version of this engine size. Power output was 40 bhp at 4,000 rpm and torque 64 lbf·ft at 1,900 rpm.
* 1954-1971 Morris Oxford
* 1955-1958 MGA
* 1954-1962 Nash Metropolitan 1500
* 1953-1968 MG Magnette
* 1956-1958 Austin A40 Cambridge
* 1956-1958 Wolseley 15/50
* 1957-1965 Wolseley 1500
* 1958-1961 Wolseley 15-60
* 1957-1965 Riley 1.5
* 1959-1961 Riley 4/68
* 1959-1965 Rochdale Olympic
* 1956-1961 Austin 152 & Morris J2 1/2 ton van
* 1958-1960 Morris Major Series I & II and Austin Lancer Series I & II
* Hindustan Ambassador
* Navigator 1500 Marine engine
A special Twin-Cam (DOHC) version of the 1.5 L B-Series engine was produced for the MGA. Output was 110 bhp (82 kW) in the high compression (9.9:1) version and 100 bhp (75 kW) in the normal (8.3:1) version. The engine block was cast iron but the crossflow cylinder head was of aluminium alloy. Drive to the twin camshafts was by chain using a half speed shaft running in the space that would have been occupied by the conventional camshaft. This engine gained a reputation for being unreliable in service, especially in the high compression version which needed high octane fuel, but this has now been largely overcome.
* 1958-1960 MGA Twin-Cam
1.6 litre engines
The engine was enlarged to 1.6 L (1588 cc) in 1958 by increasing the bore to 75.41 mm (3 in).
* 1958-1961 MGA 1600
* 1959-1961 Austin A55 Cambridge
* 1961-1971 Wolseley 16-60
* 1961-1969 Riley 4/72
* Navigator 1600 Marine engine
1.6 litre Mark II engines
The engine was enlarged to 1622 cc in 1961 with another bore increase, this time to 76.2 mm (3 in).
* 1961-1962 MGA Mark II
* 1961-1967 Austin 152 & Morris J2 1/2 ton van
* 1974-1978 Sherpa van
* 1959-1971 Morris Oxford
* 1961-1963 Morris Major Elite
1.8 litre engines
The engine was enlarged again to 1.8 L (1789 cc) in 1962. Bore was 80.26 mm (3.2 in) and stroke was 88.90 mm (3.5 in). The engine at first had a 3 bearing crankshaft with a 5 bearing version appearing in 1964.
There was also a diesel version of this capacity.
* 1962-1980 MGB
* 1964-1975 Austin 1800
* 1967-1972 Wolseley 18-85
* 1971-1978 Morris Marina 1.8
* 1964-1975 Morris 1800
* 1975-1978 Austin/Morris Princess 1.8
* 1964-1967 TVR Grantura
2.5 litre engines
There was a 2433 cc six cylinder unit that was used in some Australian models such as the Austin Freeway.
The C-Series engine was the shortest lived
out of the triumvirate of BMC engines, and has since gained infamy
for being the motive power behind of the MGC and Austin 3-Litre.
Unloved, but not unworthy
The C-Series engine first made an appearance
in 1954 in the Austin A90 Westminster, and unlike the A and B-Series
units, it was designed at the Morris engines drawing office in
Coventry. As it was devised by a different set of engineers, it
is unsurprising to learn that it shares little in common with
the two smaller units.
One important difference, is that the camshaft and and pushrods are located on the plug side of the engine. The advatage of this is that it allows the designer to separate inlet ports. This advantage was negated somewhat by the fact that the main inlet gallery was cast in one with the head. This was fed through two ports via a "Y-shaped" branch manifold, from a single carburettor. A twin-carb set-up was effected by the use of a twin-port inlet manifold (as seen in the Wolseley 6/90).
The bottom-end employed a counter-balanced crankshaft with four main bearings; vibration was absorbed by a rubber damper. Like the B-Series, this engine employed Vandervell copper-lead bearings - but due to its newer design, this was used from the beginning. Bore and stroke were 79.4 x 89mm, the engine capacity was 2639cc and maximum power was 85bhp by 4000rpm (in the SU-carburetted Morris Isis) or 83bhp (in Zenith carburetted Austin version).
By 1957, this specification had improved (thanks to a raised compression ratio) to 92bhp at 4500rpm in the A95 Westminster and in twin-carburettor form, 102bhp at 4600rpm in the A105. This was the first BMC engine to produce in excess of 100bhp, when it was announced in the Austin-Healey 100/6 type BN4 in 1956. The following year, the 'Healey's output was upped significantly to 117bhp at 4750rpm, thanks to the introduction of a new cylinder head incorporating separate manifolds - it was in this form that the 'Healey achieved its first rallying victory.
When the Farina-styled A99 came along in 1959, the C-Series was expanded to meet the task. The expansion to 3-litres was effected by increasing the bore to 83.3mm, which resulted in an new engine capacity of 2912cc. Power was also up to 112bhp (gross) at 4750rpm; the Austin-Healey version developed a healthier 124bhp (net) at 4500rpm. Following this, the 'Healey was then a recipient of a triple-SU HS4 carburettor set-up, boosting the power still further to 132bhp.
For the 1968 launch of the Austin 3-Litre, a seven-bearing crankshaft was introduced, and it was in this form that the C-Series saw out its final days in this and the MGC. Production lasted until 1971.
...more BMC C-Series engine
Austin C-Series engine in an Austin-Healey 3000 Mark II
The BMC C-Series was a straight-6 automobile engine produced from 1956 to 1971. Unlike the Austin designed A and B-series engines, it came from the Morris engines drawing office in Coventry. Displacement was 2.6 to 2.9 L (2912 cc) with an 83.3 mm bore and 88.9 mm stroke.
* 2.6 L (2639 cc) 77x89 mm
* 1954-1959 Wolseley 6/90
* 1954-1959 Austin Westminster A90/A95/A105
* 1955-1958 Morris Isis
* 1958-1959 Riley Two-Point-Six
* 1956-1959 Austin-Healey 100-6
* 2.9 L (2912 cc) 83.36x88.9 mm. Four bearing crankshaft.
* 1959-1968 Austin Westminster A99/A110
* 1959-1968 Wolseley 6/99 and 6/110
* 1959-1964 Vanden Plas Princess 3-Litre
* 1959-1967 Austin-Healey 3000
* 2.9 L (2912 cc) 83.36x88.9 mm. Seven bearing crankshaft.
* 1967-1971 Austin 3-Litre
* 1968-1970 MGC
An enthusiastic and active worldwide owners club called the Cambridge-Oxford Owners Club caters for the 'C-Series'-powered Farina and pre-Farina cars and their 'Cambridge' derived four cylinder 'B-Series' sisters. The club aims to keep the cars on the road, provides advice, spares and a social forum for enjoying the cars.