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 until 2000 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.

A version of the A Series engine was used as the auxiliary power unit on the British Centurion Main Battle Tank.

pecifications

A versions

803

The original A-Series engine displaced just 803 cm³ 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 until 1956.

Applications:
* 1952–1956 Austin A30, 28 hp (21 kW) at 4400 rpm and 40 lbf·ft (54 N·m) at 2200 rpm
* 1952–1956 Morris Minor Series II, 30 hp (22 kW) at 4800 rpm and 40 lbf·ft (54 N·m) at 2400 rpm

948

1956 saw a displacement increase, to 948 cm³. This was accomplished by boring the block out to 62.9 mm while retaining the original 76.2 mm stroke. It was produced through to 1964.

Applications:
* 1956–1962 Austin A35, 34 hp (25 kW) at 4750 rpm and 50 lbf·ft (68 N·m) at 2000 rpm
* 1956–1962 Morris Minor 1000, 37 hp (28 kW) at 4750 rpm and 50 lbf·ft (68 N·m) at 2500 rpm
* 1958–1961 Austin A40 Farina, 34 hp (25 kW) at 4750 rpm and 50 lbf·ft (68 N·m) at 2000 rpm
* 1958–1961 Austin-Healey Sprite, 43 hp (32 kW) at 5200 rpm and 52 lbf·ft (71 N·m) at 3300 rpm
* 1961–1962 Austin A40 Farina MkII, 37 hp (28 kW) at 5000 rpm and 50 lbf·ft (68 N·m) at 2500 rpm
* 1961–1964 Austin-Healey Sprite MkII, 46 hp (34 kW) at 5500 rpm and 53 lbf·ft (72 N·m) at 3000 rpm
* 1961–1964 MG Midget, 46 hp (34 kW) at 5500 rpm and 53 lbf·ft (72 N·m) at 3000 rpm

A diesel version of the 948 cc A-Series engine (producing Convert|15|hp|kW|0|abbr=on @ 2,500 RPM and 38 lbf ft (51 Nm) torque @ 1,750 RPM) was produced for the BMC Mini Tractor. It was developed with the help of Ricardo Consulting Engineers.

848

The 62.9 mm bore was retained for 1959s 848 cm³ Mini version. This displacement was reached by dropping the stroke to 68.26 mm. This engine was produced through to 1980 for the Mini, when the A+ version supplanted it.

Applications:
* 1959–1969 Austin Seven/Austin Mini/Morris Mini, 34 hp (25 kW) at 5500 rpm and 44 lbf·ft (60 N·m) at 2900 rpm
* 1961–1962 Riley Elf/Wolseley Hornet, 34 hp (25 kW) at 5500 rpm and 44 lbf·ft (60 N·m) at 2900 rpm
* 1964–1968 Mini Moke, 34 hp (25 kW) at 5500 rpm and 44 lbf·ft (60 N·m) at 2900 rpm
* 1969–1980 Mini 850/City, 33 hp (25 kW) at 5300 rpm and 44 lbf·ft (60 N·m) at 2900 rpm

997

The one-off 997 cm³ version for the Mini Cooper used a smaller 62.43 mm bore and longer 81.28 mm stroke. It was produced from 1961 through to 1964.

Applications:
* 1961–1964 Austin/Morris Mini Cooper, 55 hp (41 kW) at 6000 rpm and 54 lbf·ft (73 N·m) at 3600 rpm

998

The Mini also got a 998 cm³ 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 until 1980.

Applications:
* 1962–1969 Riley Elf/Wolseley Hornet, 38 hp (28 kW) at 5250 rpm and 52 lbf·ft (71 N·m) at 2700 rpm
* 1966–1982 Mini Moke, Australian Mokes.
* 1983–1993 Mini Moke, Portuguese Mokes.
* 1964–1969 Austin/Morris Mini Cooper, 55 hp (41 kW) at 5800 rpm and 57 lbf·ft (77 N·m) at 3000 rpm
* 1967–1980 Austin/Morris Mini, 38 hp (28 kW) at 5250 rpm and 52 lbf·ft (71 N·m) at 2700 rpm
* 1969–1975 Mini Clubman, 38 hp (28 kW) at 5250 rpm and 52 lbf·ft (71 N·m) at 2700 rpm
* 1969–1980 Mini Clubman (automatic), 41 hp (31 kW) at 4850 rpm and 52 lbf·ft (71 N·m) at 2750 rpm

1098

The 1.1 L (1098 cm³) 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 to 1980.

Applications:
* 1962–1967 Austin A40 Farina, 48 hp (36 kW) at 5100 rpm and 60 lbf·ft (81 N·m) at 2500 rpm
* 1962–1971 Morris 1100/Morris Minor 1000, 48 hp (36 kW) at 5100 rpm and 60 lbf·ft (81 N·m) at 2500 rpm
* 1962–1968 MG 1100, 55 hp (41 kW) at 5500 rpm and 61 lbf·ft (83 N·m) at 2500 rpm
* 1962–1964 Austin-Healey Sprite MkII, 56 hp (42 kW) at 5500 rpm and 62 lbf·ft (84 N·m) at 3250 rpm
* 1962–1964 MG Midget, 56 hp (42 kW) at 5500 rpm and 62 lbf·ft (84 N·m) at 3250 rpm
* 1963–1974 Austin 1100, 48 hp (36 kW) at 5100 rpm and 60 lbf·ft (81 N·m) at 2500 rpm
* 1963–1967 Vanden Plas Princess 1100, 55 hp (41 kW) at 5500 rpm and 61 lbf·ft (83 N·m) at 2500 rpm
* 1964–1966 Austin-Healey Sprite MkIII, 59 hp (44 kW) at 5750 rpm and 65 lbf·ft (88 N·m) at 3500 rpm
* 1964–1966 MG Midget MkII, 59 hp (44 kW) at 5750 rpm and 65 lbf·ft (88 N·m) at 3500 rpm
* 1965–1968 Riley Kestrel/Wolseley 1100, 55 hp (41 kW) at 5500 rpm and 61 lbf·ft (83 N·m) at 2500 rpm
* 1973–1975 Austin Allegro, 49 hp (37 kW) at 5250 rpm and 60 lbf·ft (81 N·m) at 2450 rpm
* 1975–1980 Austin Allegro, 45 hp (34 kW) at 5250 rpm and 55 lbf·ft (75 N·m) at 2900 rpm
* 1968–1982 Mini Moke Australia only.
* 1975–1980 Mini Clubman, 45 hp (34 kW) at 5250 rpm and 56 lbf·ft (76 N·m) at 2700 rpm
* 1979–1980 Mini 1100 Special, 45 hp (34 kW) at 5250 rpm and 56 lbf·ft (76 N·m) at 2700 rpm

1071

The 1071 cm³ 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. Paired with the even rarer 970 cc version, below, it became that rarest of things: an oversquare A-series engine.

Applications:
* 1963–1964 Austin/Morris Mini Cooper S, 70 hp (52 kW) at 6000 rpm and 62 lbf·ft (84 N·m) at 4500 rpm

970

The Mini Cooper S next moved on to a 970 cm³ version. It had the same 70.6 mm bore as the 1071 cm³ Cooper S but used a shorter 61.91 mm stroke. It was produced from 1964 through to 1967.

Applications:
* 1964–1967 Austin/Morris Mini Cooper S, 65 hp (48 kW) at 6500 rpm and 55 lbf·ft (75 N·m) at 3500 rpm

1275

The largest A-Series engine displaced 1.3 L (1275 cm³). 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 until 1980 when it was replaced by an A+ version.

Applications:
* 1964–1971 Austin/Morris Mini Cooper S, 76 hp (57 kW) at 5800 rpm and 79 lbf·ft (107 N·m) at 3000 rpm
* 1966–1970 Austin-Healey Sprite MkIV, 65 hp (48 kW) at 6000 rpm and 72 lbf·ft (98 N·m) at 3000 rpm
* 1966–1974 MG Midget MkIII, 65 hp (48 kW) at 6000 rpm and 72 lbf·ft (98 N·m) at 3000 rpm
* 1967–1968 MG 1300/Wolseley 1300, 58 hp (43 kW) at 5250 rpm and 69 lbf·ft (94 N·m) at 3000 rpm
* 1967–1968 Riley Kestrel 1300, 58 hp (43 kW) at 5250 rpm and 69 lbf·ft (94 N·m) at 3000 rpm
* 1967–1968 Vanden Plas Princess 1300, 58 hp (43 kW) at 5250 rpm and 69 lbf·ft (94 N·m) at 3000 rpm
* 1967–1973 Morris 1300, 58 hp (43 kW) at 5250 rpm and 69 lbf·ft (94 N·m) at 3000 rpm
* 1967–1974 Austin 1300, 58 hp (43 kW) at 5250 rpm and 69 lbf·ft (94 N·m) at 3000 rpm
* 1967 MG 1275/Riley 1275, 58 hp (43 kW) at 5250 rpm and 69 lbf·ft (94 N·m) at 3500 rpm
* 1967 Wolseley 1275, 58 hp (43 kW) at 5250 rpm and 69 lbf·ft (94 N·m) at 3500 rpm
* 1967 Vanden Plas Princess 1275, 58 hp (43 kW) at 5250 rpm and 69 lbf·ft (94 N·m) at 3500 rpm
* 1968–1969 Riley Kestrel 1300/Riley 1300, 70 hp (52 kW) at 6000 rpm and 77 lbf·ft (104 N·m) at 3000 rpm
* 1968–1971 Austin America (automatic), 60 hp (45 kW) at 5250 rpm and 69 lbf·ft (94 N·m) at 2500 rpm
* 1968–1973 Wolseley 1300 (manual), 65 hp (48 kW) at 5750 rpm and 71 lbf·ft (96 N·m) at 3000 rpm
* 1968–1973 MG 1300 MkII, 70 hp (52 kW) at 6000 rpm and 77 lbf·ft (104 N·m) at 3000 rpm
* 1968–1974 Vanden Plas Princess 1300 (manual), 65 hp (48 kW) at 5750 rpm and 71 lbf·ft (96 N·m) at 3000 rpm
* 1968 MG 1300/Riley Kestrel 1300, 65 hp (48 kW) at 5750 rpm and 71 lbf·ft (96 N·m) at 3000 rpm
* 1969–1971 Morris 1300GT, 70 hp (52 kW) at 6000 rpm and 74 lbf·ft (100 N·m) at 3250 rpm
* 1971–1982 Mini Moke Californian Australian only.
* 1969–1974 Mini 1275GT, 59 hp (44 kW) at 5300 rpm and 65 lbf·ft (88 N·m) at 2550 rpm
* 1969–1974 Austin 1300GT, 70 hp (52 kW) at 6000 rpm and 74 lbf·ft (100 N·m) at 3250 rpm
* 1971–1980 Morris Marina, 60 hp (45 kW) at 5250 rpm and 69 lbf·ft (94 N·m) at 2500 rpm
* 1971 Austin Sprite, 65 hp (48 kW) at 6000 rpm and 72 lbf·ft (98 N·m) at 3000 rpm
* 1973–1980 Austin Allegro, 59 hp (44 kW) at 5300 rpm and 69 lbf·ft (94 N·m) at 3000 rpm
* 1974–1980 Mini 1275GT, 54 hp (40 kW) at 5300 rpm and 65 lbf·ft (88 N·m) at 2550 rpm

A-Plus versions

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.

998 Plus

The A-Plus version of the 998 cm³ motor was produced from 1980 until 1992.

Applications:
* 1980–1982 Mini 1000/City/HL, 39 hp (29 kW) at 4750 rpm and 52 lbf·ft (71 N·m) at 2000 rpm
* 1980–1982 Austin Allegro, 44 hp (33 kW) at 5250 rpm and 52 lbf·ft (71 N·m) at 3000 rpm
* 1980–1990 Austin Metro, 41 hp (31 kW) at 5400 rpm and 51 lbf·ft (69 N·m) at 2700 rpm
* 1982–1988 Mini HLE/City E/Mayfair, 40 hp (30 kW) at 5000 rpm and 50 lbf·ft (68 N·m) at 2500 rpm
* 1981-1986 Austin Metro HLE Auto bhp|46|0 and Auto ft.lbf|52|0
* 1988–1992 Mini City/Mayfair, 42 hp (31 kW) at 5250 rpm and 58 lbf·ft (79 N·m) at 2600 rpm

1275 Plus

The big 1.3 L (1275 cm³) engine was also given the "A-Plus" treatment. This lasted from 1980 until 2000, making it the last of the A-Series line.

Applications:
* 1980–1982 Austin Allegro, 62 hp (46 kW) at 5600 rpm and 72 lbf·ft (98 N·m) at 3200 rpm
* 1980–1984 Morris Ital, 61 hp (46 kW) at 5300 rpm and 69 lbf·ft (94 N·m) at 2950 rpm
* 1980–1990 Austin Metro, 63 hp (47 kW) at 5650 rpm and 72 lbf·ft (98 N·m) at 3100 rpm
* 1982–1989 MG Metro, 72 hp (54 kW) at 6000 rpm and 73 lbf·ft (99 N·m) at 4000 rpm
* 1983–1985 Austin Maestro HLE, 64 hp (48 kW) at 5500 rpm and 73 lbf·ft (99 N·m) at 3500 rpm
* 1983–1993 Austin Maestro, 68 hp (51 kW) at 5800 rpm and 75 lbf·ft (102 N·m) at 3500 rpm
* 1984–1989 Austin Montego, 68 hp (51 kW) at 5600 rpm and 75 lbf·ft (102 N·m) at 3500 rpm
* 1989–1990 MG Metro GTa, 73 hp (54 kW) at 6000 rpm and 73 lbf·ft (99 N·m) at 4000 rpm
* 1990–1991 Mini Cooper, 61 hp (46 kW) at 5550 rpm and 61 lbf·ft (83 N·m) at 3000 rpm
* 1990–1991 Mini Cooper S, 78 hp (58 kW) at 6000 rpm and 78 lbf·ft (106 N·m) at 3250 rpm
* 1991–1996 Mini Cooper 1.3i/Cabriolet, 63 hp (47 kW) at 5700 rpm and 70 lbf·ft (95 N·m) at 3900 rpm
* 1991–1996 Mini Cooper S 1.3i, 77 hp (57 kW) at 5800 rpm and 80 lbf·ft (108 N·m) at 3000 rpm
* 1992–1996 Mini Sprite/Mayfair, 50 hp (37 kW) at 5000 rpm and 66 lbf·ft (89 N·m) at 2600 rpm

1275 Turbo

Turbo versions lasted from 1983 until 1990.

Applications:
* 1983–1989 MG Metro Turbo, 94 hp (69 kW) at 6130 rpm and 85 lbf·ft (115 N·m) at 2650 rpm
* 1989–1990 Mini ERA Turbo, 94 hp (69 kW) at 6130 rpm and 85 lbf.ft at 3600 rpm

The later ERA version had a revised setting in the ECU to give less low down torque to stop premature gearbox wear.

1275 TPi

A special "twin-port injection" version of the 1.3 L (1275 cm³) engine was developed by Rover engineer, Mike Theaker. It was the last A-Series variant, produced from 1997 through to 2000.

Applications
* 1997–2000 Mini Cooper 1.3i (TPi), 63 hp (47 kW) at 5500 rpm and 70 lbf·ft (95 N·m) at 3000 rpm

References

Northey, Tom, editor in chief. "World of Automobiles" (London: Orbis Publishing, 1974), Volume 9, p.1054, "Mini", and Volume 2, p.121, "Austin Allegro."
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