|1936 to 1956
Consists of four letters, followed by the engines number.
(1) MODEL (2) Valves (3) Bore & H.P. (4) Make
U Morris 8 S Sidevalve H 57mm 8HP M Morris
M Morris 10/4 P OHV J 63.5mm 10HP G M.G.
X late Morris 10/4 C OHC A 66.5mm 11HP W Wolseley
T Morris 12/4 B 69.5mm 12HP C Commercial
Q 2ltr 6 cyl E 72mm 13HP
O 3 1/2 ltr 6cyl D 75mm 14HP
A Austin A30 D 61.5mm 6cyl
H 69mm 6cyl
ie; XPAG 1250cc MG TB OHV engine 11HP
XPJM 1140cc Morris 10/4 OHV engine 10HP
XPJW 1140cc Wolseley 10/40 OHV engine 10HP
USHM 918cc Morris Minor MM SV engine 8HP
XPEG 1488cc MG TF OHV engine 13HP
MPJG 1292cc MG TA OHV engine 12HP
MPJM 1292cc Morris 12/4 OHV engine 10HP
MPJW 1292cc Wolseley 12/48 OHV engine 10HP
APHM 803cc Morris Minor MM OHV engine 8HP (first 'A' series)
APJM 948cc Morris Minor 1000 OHV engine 10HP
TPBG 1549cc MG VA OHV engine 12HP
TPDG 1705cc MG 'Cream Cracker' TA engine
QPJG 2322cc MG WA OHV engine 18HP
QPHW 2561cc Wolseley 18/80 OHV engine 18HP
BMC 'B' Series, 1947 to 1981.( First real 'B' series was in 1953.)
With the arrival of Austin based 'A' & 'B' series amongst those used, a system of engine 'cc' was added. It basically followed the post 1956 system, but put 'BP' infront to denote 'B' series, 'P'ush rod ohv.The first car to use the 'B' series was the M.G. Magnette ZA, in 1489cc form, in 1953. The earlier Austin A40 Devon 1200cc unit was that developed into this later 1489cc and 1200cc 'B'.
ie. BP15M was a 1489cc Morris Oxford.
BP15GA was the ZA Magnette of 1489cc.
BP15GC an improved ZA Magnette, with full flow oil filter.
BP15GB was the first MGA 1489cc engine,
BP15GD followed it.
BC16GB was the MGA Twin Cam, 'B' series, 'C' camshaft.
1956 to 1970 'A', 'B', and 'C' Series engine Prefix
The 'BP' prefix was dropped once BMC had its three engine types, A, B, and C. Again, there is a prefix, consisting of a number, then letter/letter/letter, then the engine number.
Cubic capacity Make Type Ancillaries Compression
8 = 803cc A = Austin A to Z A = automatic H = high comp
9 = 948cc B = BMC Industrial ,, M = manumatic clutch L = low comp
10 = 1098cc G = M.G. ,, P = police spec.
12 = 1200cc H = miscellaneous ,, U = central gear change
12 = 1275cc J = Commercial ,, N = column change
15 = 1498cc K = IH Metro Mite ,, O = overdrive
16 = 1588cc M = Morris ,,
16 = 1622cc R = Riley ,,
18 = 1798cc V = Van den Plas ,,
22 = 2200cc W = Wolseley ,,
25 = 2500cc AC, AD, AE, HLC, J, K, ML, Y, Z = Comercial
26 = 2600cc AMW = Austin-Morris-Woseley
29 = 2912cc C = Farina with alternator
C or F = Metropolitan
ie, 15W / U / H 1234 1489cc Wolseley 15/50, central gear change, high comp.
15GE / U / H 1234 1489cc M.G. Magnette Mk3, central gear change, high comp.
15F / N / H 1234 1489cc Metropolitan column change, high comp.
16AMW / U / H 1234 1622cc Austin, Morris & Wolseley Farina, central gear, high c.
16GA / U / H 1234 1588cc MGA 1600,central gear change, high comp.
15AC / N / L 1234 1489cc Austin 15cwt van, column change, low comp.
18GA / O / H 1234 1798cc MGB 3 main B. with overdrive, high comp.
29WA / O / H 1234 2912cc Wolseley 6/110, overdrive, high comp.
29GA / A / H 1234 2912cc MGC GT, automatic, high comp.
After 1970 the system was again changed, and simple types were just numbered.
85 848cc 99 998cc 10 1098cc 12 1275cc
16 1622cc 18 1798cc 22 2200cc
with either a 'V' or an 'H' after it. 16V meant vertical, (in-line), as in the Sherpa van, or 18V as in both the later Sherpa and MGB, and Morris Marina 1800. 12V would be in an Ital, and 12H in Metro, H meaning horizontal, (FWD.) It was the group of numbers/letters after that denoted the fitment, ie, 18V-584F for a UK specification engine on the MGB. 18H was in the FWD 1800.
As an aside, the big BMC 6 cylinder 'C' series was a Morris Engines design, where as
the 'A' & 'B' were Austin designed.
BMC 'B' SERIES ENGINES USE (1953 to 1981)
Model cc Prefix BHP/RPM Torque
Austin A40 pre-1953 1200 1H *
Austin A40 Devon 1200 BP12A 40/4500 58lb/ft
Austin A40 Somerset 1200 BP12A 42/4500 58
Austin A40 Sports 1200 BP12A 42/4500 58
Austin A40 Sports 1200 BP12A 46/4500 58
Austin A40 Cambridge 1200 BP12A 42/4500 58
Morris Cowley series 1 1200 BP12M 40/4500 58
Austin Metropolitan 1200 1200 BP12A 42/4500 58
Austin Metropolitan 1500 1489 BP15M 52/4500 70
Nash Metrpolitan 1500 1489 15F (USA only) 52/4500 70
Massey Harris combine
harvester 1200 1HLC 40/4500 50
Morris Oxford series 2 1489 BP15MH 50/4500 70
Morris Oxford series 2 1489 BP15ML 45/4500 65 (LC)
Morris Cowely series 2 1489 BP15M 50/4500 70
Morris Oxford series 3 1489 15M 55/4500 72
Morris Oxford series 4 1489 15M 55/4500 72
Wolseley 15/50 1489 BP15W 50/4500 70
Wolseley 15/50 1489 15AMW 55/4500 72
Wolseley 1500 Mk1 1489 BP15LAW 50/4500 70
Wolseley 1500 Mk2 1489 15W, 15WA 55/4500 72
Riley 1.5 Mk1 1489 15R, 15RA 60/4800 77
Riley 1.5 Mk2 1489 15RB 66/5200 82
M.G. Magnette ZA 1489 BP15GA 60/4800 77
M.G. Magnette ZA & ZB 1489 BP15GC, 15GC 68/5200 82
M.G. Magnette ZB 1489 BP15HGC, 15HGC 68/5200 82
M.G. MGA 1489 BP15GB, 15GB 68/5200 82
M.G. MGA 1489 15GD 72/5500 85
M.G. MGA 1600 1588 16GA 80/5600 87
MGA Twin Cam 1588 BC16GB 108/6700
Austin/Morris 1/2ton, 1489 BP15ML,
van,pick up 15AC, VS15C 50/4200 74 (LC)
Diesel Engine 1489 BP15J,15Y,15J,15Z 40/4200 90
Austin A50 Cambridge 1489 1H 50/4500 70
Austin A55 Cambridge 1489 15 55/4500 72
Austin A55 Mk2 Camb. 1489 15AMW 55/4500 82
Morris Oxford series 5 1489 15AMW 55/4500 82
Wolseley 15/60 1489 15AMW 55/4500 82
IH Metro Mite 1489 15K ??/???? ?? (similar to Met)
Riley 4/68 1489 15RA, 15RB 68/5200 85
M.G. Magnette Mk3 1489 15GE 66/5200 85
Morris Oxford series 6 1622 16AMW, 16AA 61/4500 90
Austin A60 Cambridge 1622 16AMW, 16AA 61/4500 90
Wolseley 16/60 1622 16AMW,16AA 61/4500 90
M.G. Magnette Mk4 1622 16GE, 16GF 68/5200 89
Riley 4/72 1622 16RA,16GF 72/5500 90
M.G. MGA 1600 Mk2 1622 16GC 90/5500 97
A60 commercials 1622 16AC,16AE 61/4500 90
Farinas with alternators 1622 16C (1971 only) 61/4500 90
BMC 1/2 ton van 1622 16AD 61/4500 90
Sherpa van 1622 16V 58/4500 82 (LC)
Sherpa van 1798 18V 80/5000 85 (LC)
Morris Marina 1800 1798 18V 85/5000 90
Morris Marina 1800TC 1798 18V 95/5400 110
Austin 1800 Mk1 1798 18C,18AMW 80/5000 90
Morris 1800 Mk1 1798 18C,18AMW 80/5000 90
Wolseley 18/85 1798 18C,18AMW 80/5000 90
all 1800 Mk2 1789 18C 86/5300 92
all 1800 Mk3 1798 18H 86/5300 95
Austin 1800S 1798 18H 96/5400 106
M.G. MGB (3 mainbearings) 1798 18G,18GA 95/5400 110
M.G. MGB* (5 mainbearings) 1798 18GB,18GD,18GG,
18GK,18V 95/5400 110
(power down to 84bhp by 1975 for USA.)
Hundustani 1489 ? 50/4200 74
Navigator Marine 1489 ? 42/4200 60
Navigator Marine 1622 ? 58/4500 85
Massy Harris Combine 1200 1HLC *
* Austin A40 cars built prior to 1953 used the earlier type 2A engine ranging from 800cc to 1200cc. This was not a B-series. Although it looked similar, the earlier engine was shorter length, lighter weight, and has a smaller (weaker) crankshaft.
Differing compresion ratios gave different BHP/Torque figures. (LC) indicates low comp, usually about 7.2 to 1, the normal, or high comp, was usually 8.3 to 1. Later cars such as the MGA & MGB ran with 9 to 1 and 9.5 to 1, as did some 1800 fwd cars. An 'H' or 'L' in the number is usually a clue to the ratio, though a simple change of pistons will change the ratio if the 'dish' differs in the crown.
48G is a 'B' series Gold Seal reconditioned unit. The 'A' series was 8G, and the 'C' series 68G. (** All pre-1956 reconditioned engines were prefixed 8G, only when the Gold Seal Exchange engine arrived, was there any difference). On a late note, BHM 1109 turns out to be a Marina 1.8-GT-Special MK 2 exchange engine (Austin Marina in the USA).
The MGB used the 1800 for a long time, so there were codes to denote the differences between the engines, peculiar to MG;-
prefix bearings model market dates if known
18G 3 Mk1 GHN3/D3 all Oct 1962/April64
18GA 3 Mk1 GHN3/D3 all April 1964/Oct64
18GB 5 Mk1 GHN3/D3 all Oct 1964/67
18GD 5 Mk2 GHN4/D4 UK/Europe Oct 1967/69
18GF 5 Mk2 GHN4/D4 USA Oct 1967/69
18GG 5 Mk2 GHN5/D5 UK/Europe Oct 1969/71
18GH* 5 Mk2 GHN5/D5 Europe Oct 1969/70
18GJ 5 Mk2 GHN5/D5 USA Oct 1969/70
18GK 5 Mk2 GHN5/D5 USA Oct 1970/71
18V** 5 Mk3 GHN5/D5 see below Oct 1971 onwards
* After 18GH there were extra letters after the prefix, 'U' still meant central gearchange; 'RU' now meant overdrive; 'We' all synchromesh gearbox; 'RWe' all synchro with overdrive; 'Rc' automatic gearbox.
** 18V was followed with a code for the market, such as if a 'Y' appears in the prefix, it is a Europe spec car; if a 'F' a UK spec car; if a 'Z' a north America spec car. An 'AE' after 1975 is a car with a catylist fitted for California. The emmission controls, timing changes, etc, require a workshop manual to identify the huge numbers of changes.
BMC 'A' Series Engines ( 1952 to 1999)
Just like the 'B' series, BMC used the same system as above to denote the use of the engine.
Car Model Engine cc Prefix number
Austin A30 803cc 2A
Austin A35 948cc 9A
Austin A35 van (optional) 848cc 8G ( post 1962 all GPO.)
Austin A40 Mk1 948cc 9A or 9D
Austin A40 Mk2 948cc 9DB
Austin A40 Mk2 1100 1098cc 10D or 10DD
Austin Healey Sprite Mk1 948cc 9CG or 9CC
Sprite Mk2/ MG Midget Mk1 1098cc 10CG
Sprite Mk3/ MG Midget Mk2 1098cc 10CC ( 2" main bearings.)
Sprite Mk4/ MG Midget Mk3 1275cc 12CC or 12CE home market
.. .. .. 12CD or 12CJ N. America
.. .. .. after Oct '72, 12V/586F/H home market
.. .. .. .. 12V/671Z/L N. America
Austin Allegro 1275cc 12H/A ( same as Metro)
Austin Mini 848cc 8A
Morris Mini 848cc 8MB
Austin & Morris Mini after 1962 848cc 8AM
Austin/Morris Mini automatic 848cc 8AH
Mini Automatic closed circuit breather 848cc 8AK
Mini floor change closed circuit breather 848cc 8AJ
Mini GPO saloon & van 848cc 85H ( 1" restrictor in carb.)
Mini Clubman 1098cc 10H
Mini 1000 998cc 99H
Mini 1000 unleaded high comp 998cc 99HE20
Mini 1000 unleaded low comp 998cc 99HE22
Mini 1000 Automatic 998cc 99HB82P
Mini 1275cc 1275cc 12H
Mini Moke 848cc 8AC
1275GT & Cooper Mk3 'S' 1275cc 12H
Later Cooper models 1275cc 12A
Wolseley Hornet, Riley Elf Mk1 848cc 8WR
Wolseley Hornet, Riley Elf Mk2 998cc 9WR
Austin, Morris, Wolseley fwd 1100 1098cc 10AMW, 10H
.. .. .. .. 1098cc closed circuit breather 10AH
Austin, Morris, Wolseley 1100 Automatic 1098cc 10AG
.. .. .. .. 1098cc closed circuit breather 10AJ
MG 1100 Mk1 & Mk2, Riley 1100 1098cc 10GR
MG & Riley 1100 closed circuit breathing 1098cc 1965 on 10GRB
Vanden Plas 1100 1098cc 10GR, 10V
MG 1300 Mk1 1275cc 12G (single SU.)
MG 1300 Mk2 , Riley 1300 1275cc after April '68 12GR
All fwd 1300 Automatic 1275cc 12A
Vanden Plas 1300 1275cc 12GR, 12V
Austin 1300 'S' Mk1, Mk2 1275cc 12FA
Austin 1300 'S' Mk3 1275cc 12H
Austin Maestro/Montego 1.3 1275cc 12HA ( 'A' Plus)
(Uses Marina 1.3 type block.)
Austin Metro 1 ltr 998cc 99HA ( all 'A' Plus)
Metro 1 ltr1985 on 998cc 99HA, 99HB, 99HC, 99HD,
Metro 1300 HLE 1275cc 12HA08AA
.. .. 1275cc 12HB, 12HC, 12HD, 12HE,
MG Metro 1300 leaded fuel pre 1989 1275cc 12H996AA, 12HD24
MG Metro 1300 unleaded post mid-1989 1275cc 12HF01
MG Metro Turbo leaded fuel pre 1989 1275cc 12HD26
MG Metro Turbo unleaded 1275cc 12HF01
Austin Metro Sport .. 1275cc 12HF02
Austin Metro GTa .. 1275cc 12HF02
Austin Metro's with unleaded engines, 1275cc 12HE24, 35, 39, 40, 41,
42, 67 up to 75.
Morris Minor Series 2 803cc APHM
Morris Minor 1000 series 3 948cc APJM
Morris Minor 1000 series 4 after 1956 948cc 9M
Morris Minor 1000 series 5 1098cc 10MA
Morris Minor series 5, close circuit breather 1098cc 10ME
Morris 1000 GPO van 948cc 8AG after 1962
Morris 1000 van, low compression 1098cc 10AB
Morris 1000 van closed circuit breather 1098cc 10V
Morris Marina 1300 1275cc 12V639-EHZnnnnnn
Mini Cooper 997cc & 1070cc 'S' 9F/SA/H comp 9.1
Mini Cooper 997cc 9F/SA/L 8.3
Mini Cooper 970cc 'S' 9F/SA/X 10
Mini Cooper 1275cc 'S' 9F/SA/Y 9.75
Mini Cooper 998cc 9FA/SA/H 9.1
Mini Cooper 998cc 9FA/SA/L 8.3
Mini Cooper 970cc 'S' 9FC/SA/H 9.1
Mini Cooper 998cc 9FD/SA/H 9.1
Mini Cooper 1070cc 'S' 9FD/SA/H 9.1
(engine 33661 to 33948)
Mini Cooper 998cc 9FD/SA/L 8.3
Mini Cooper 970cc 'S' 9FD/SA/X 10
Mini Cooper 1275cc 'S' 9FD/SA/Y 9.75
Mini Cooper 970cc 'S' 9FE/SA/X 10
Mini Cooper 1275cc 'S' 9FE/SA/Y 9.75
Mini Cooper 1070cc 'S' 10F 8.3
Still being fitted to the 1275cc Mini as 12HE...................( 1999)
Neil Cairns, MG Engine Information Service <email@example.com>
BMC 'C' SERIES Engines
(Not a complete list)
1954 Morris Isis 2639cc C26M 85 bhp
1954 Wolseley 6/90 2639cc 26W 95
1954 Austin A90 Zenith carb 2639cc 26A 83
1956 Riley 2.6 2639cc 26R 95
1956 Austin A105 2639cc 26A 102
1956 Austin Vanden Plas A105 2639cc 26A 102
1956 Austin A95 Westminster 2639cc 26A 92
1956 Austin Healey 100/6 2639cc 26A 102
1959 Austin Healey 3000 Mk1 2912cc 29A 124
1961 Austin Healey 3000 Mk2 2912cc 29A 132
1963 Austin Healey 3000 Mk3 2912cc 29A 150
1959 Austin Westminister A99 2912cc 29A 103
1959 Wolseley 6/99 2912cc 29WA 103
1959 Vanden Plas Princess Mk1 2912cc 29VA 103
1961 Austin Westminister A110 Mk1 & Mk2 2912cc 29A 120
1961 Wolseley 6/110 Mk1 & Mk2 2912cc 29WB 120
1961 Vanden Plas Princess Mk2 2912cc 29VB 120
1967 Austin 3 Litre ( 7 main bearings,) 2912cc 29AA 124
1967 MG MGC ( ,, ,, ) 2912cc 29GA 145
The Austin models used Zenith carbs up to the farina Westminster in 1959, then they had SU's as all the others used all along. Healeys had different cylinderheads, separate manifolding, and camshafts.
GOLD SEAL EXCHANGE ENGINES
BMC like many firms did an exchange scheme for worn engines, one was the Gold Seal engine, a complete engine ready to fit and painted gold in colour. The other was the Silver Seal exchange engine, basically a short-block for the owner/garage to fit the old head,sump, and ancillories onto.
Both used a similar system of engine numbering, the original number being struck off.
Initially all engines in the scheme were prefixed 8G, soon a better system followed:
'A' series engines were prefixed 8G,- 803cc, 848cc, 948cc, 1098cc, 1275cc.
'B' series were prefixed 48G,- 1200cc, 1489cc, 1588cc, 1622cc, 1798cc.
'C' series were prefixed 68G,- 2639cc, 2912cc.
The code after was to do with rebore/regrind sizes and a job number.