MGA engine number for Grantura

[Granny Fan]

Just as a matter of interest if anyone can shed some light on this.I have an engine with the following number in my Grantura. Original engine.

12.H.22.RS.18803

Looking on internet the prefix '12' means its a 1200cc, but has 1600 stamped on block so would have thought it would start '16'
Cant find out what 'RS' stands for.
Any ideas?

[Grantura2a]

It looks like you are quoting part numbers, not the engine number. The engine number is on the tag pinned to the head. I'm not sure if it is attached to the block anywhere. See http://mgaguru.com/mgtech/engine/be102.htm

MGA 1622, March 1961 through May 1962 (and 3 main MGB)
Part Number Cyl 1&3: 12H426 On the rod: 12H427
Part Number Cyl 2&4: 12H424 On the rod: 12H425

The 12H91/92/93/94 parts may be rods from the MGB 3 main motor,
as their part numbers were 12H997 and 12H998.

Mike T
Grantura Mk 2a
Griffith 200

[Granny Fan]

The number is situated on a Alu plate between 2nd and 3rd spark plug. Is also quoted on original RF60 log book, it seems to be the engine number?

[Grantura2a]

Odd. I know that MG used a different numbering scheme for the Unipart silver and Gold seal service engines. Maybe engines supplied to other manufacturers had a different scheme as well. The 12H number is in line with the 1622 part numbers.

[Granny Fan]

Bit of a strange one, thanks or your input.