Below is a list of crankshaft identification data by forging or stamped numbers - yes, contrary to what many say/express, all cranks are forged. None are cast. They wouldn't last 2 minutes in an engine if they were cast - they'd be way too brittle. The differences are in the material used, finish machining detail and any heat treatments applied. It is by no means complete and utterly correct/infallible since Austin/Morris, British Leyland, Leyland cars, Austin Rover, rover, et al were seriously prone to not adhering to specifications and applications lists. But it is better than nothing at all!

 

22A62      850cc - Early type with oil feed for primary gear, 1.375" dia. tail

22A63      850cc - Early type with oil feed for primary gear, 1.375" dia. tail

22A298    850cc - Early type thin-nose crank, 1.375" dia. tail

12A670    850cc - Later type with 1.5" dia. tail

12A298    997cc - Original Cooper crank

12A375    997cc - Cooper crank with oil feed hole for primary gear

12A595    998cc - Early EN16T spec

12A1451   998cc - Later, pre-A+ EN16T spec

BHM1436 998cc - A+ spec, 1985 onwards (12A1451 forging)

12G82      1100cc - Standard across the board transverse A-series EN16T spec

AEG330    970cc - EN40B forged, non-cross drilled

AEG171    1071cc - EN40B forged, non-cross drilled

AEG315     1275cc - Cooper S, EN40B forging, Nitrided, 1.625" dia. big ends, non-cross drilled

AEG316     1275cc - Cooper S, EN40B forging, Nitrided, 1.625" dia. big ends, non-cross drilled

AEG479     1275cc - Cooper S, EN40B forging, Nitrided, 1.625" dia. big ends, cross drilled

AEG480     1275cc - Cooper S, EN40B forging, Nitrided, 1.625" dia. big ends, cross drilled

AEG623     1275cc - Cooper S, EN16T forging, Tuftrided, 1.625" dia. big ends

12G1287   1275cc - Non-S, EN16T with 1.625" dia. big ends

12G1288   1275cc - Non-S, EN16T with 1.625" dia. big ends

12G1505   1275cc - Non-S, EN16T with 1.75" dia. big ends

12G1683   1275cc - 12G1505 forging, non-S, EN16T with 1.75" dia. big ends, Tuftrided

CAM6232* 1275cc - Rolled-fillet radius on bearing journals, A+ with 1.75" dia. big ends

 

*Note: This crankshaft was used in all 1275cc, A+, transverse engines including the MG Metro Turbo. There are various un-confirmed opinions on the subject of whether the material was any different, or whether it was heat treated differently. It would appear that early Turbos had just the standard spec, EN16T, non-heat treated type fitted. Later examples certainly appear to have been heat-treated, probably an up-to-date, emissions-friendly version of 'Tuftriding' (a recognised ICI registered process) - possibly a forerunner to Nitro-Carburising. These crankshafts have a distinctly charcoal-grey/black finish - mostly detectable on the webs, water pump/alternator pulley end and in the rolled fillet radii. The later being fairly 'deep' and very even.