cylinder head casting numbers

[smithskids]

Hello folks, been looking through my spares and found 2 cylinder heads look similar. Both small bore but the casting numbers are a mystery to me. one is 12A1456 and has a standard looking combustion chamber, the other is CAM4810 same shaped combustion chamber but is only 69mm deep as the other is the standard 70mm.both have the small valves but the CAM4810 has double valve springs. Any ideas?

[panky]

The 456 was used on the 850, 998 Mini & 948 Sprite, the 810 on 998 Mini - A+ (1980-on) and could be lead free. The combustion chamber on the 810 should actually be slightly larger than the 456 - I guess it must have been skimmed and the double springs added in an attempt to warm it up a bit.

[smithskids]

Thanks for the info.

[tim_jnv]

The 456 was used on the 850, 998 Mini & 948 Sprite, the 810 on 998 Mini - A+ (1980-on) and could be lead free. The combustion chamber on the 810 should actually be slightly larger than the 456 - I guess it must have been skimmed and the double springs added in an attempt to warm it up a bit.

seems like you have good knowledge would you be able to list what heads where fitted to what a-series engine and what can be interchanged with what and how? in a simple format? no doubt someone will be along to assist!

[silloyd]

You may find this list helpful.

[bmcecosse]

Good old Calver He 'forgets' to mention the 202 head was fitted a goodly number of Minor 1098 engines........

[smithskids]

Thanks, a very useful list indeed. Happy 2015 to all when it comes. We are off to sample a wee dram now after half a day on the church clock, it was much easier to maintain when it was just wound up.
Cheers Iain.

[panky]

Yep that's the list I use