cooper s cylinder head

[james nash]

replacing cylinder head gasket on my 64 cooper s and note that the valve spring caps have a 'W' engraved on each one, and by the thermostat housing there is the number '12g 1805' with a capital 'R' below it and the casting number within the rocker area is the '12g 940'.

Does anyone know what these numbers refer to? I didn't know if the 'W' possibly referred to 'Westlake'.

Any replies greatly appreciated.

[Cooperman]

The original head for a 1964 car would have been an AEG163. That casting was later changed for the 12G940 as the 163 tended to crack between valves seats.
No idea what the other letters/numbers are.
If anyone wants an AEG163 fully gas-flowed and complete with new valves & guides I might sell one of mine! My '64 'S' also has a 12G940 casting to gain reliability.

[guru_1071]

the 1805 shows its a mk3 s head, the 'w' shows that they are the s steel caps.