What Engine is This

Hi all
i have a 1967 Riley Elf i have had it a couple of years waiting till i have time to start its rebuild as it is a bit of a Chicken Coupe.
It needs a new floor as it was stood with no back window in it so rain has taken its toll on the interior especially the floor and rear seat pan.
It wont be a Factry Restoration as i like to do my own thing.
But hopefully it will eventually be another Elf saved.

Can you Tell me what Engine i have in My Elf my plan was to fit a 1275 engine
I got the engine up and running last week i presumed it was an 850 but as im looking into it a bit i now wonder if its a 1100.
the engine number starts with 8G156ER and the head is a 12G202  which leads me to think its a 1100

8G156E       1100cc - Clubman, Special and Austin 1100  [ pasted from a engine identifacation web site]
David Vizard book points to 997 cooper or 1098 for this head casting number
Can you help identify this engine for me please..

Calver's engine guide says that's a factory replacement/reconditioned 1100 motor. I would think you could make it plenty peppy without having to replace it with a 1275.
I'm fairly certain the original motor would have been a 998, not an 850. The engine number should have started with 99H.
Like this one:

Hi Red
Thanks for that .
The log book still says 998 with a 9ADTAH code i presume possibly the original engine i have not looked that one up yet.
The engine fitted has removable tappet covers and no drillings in the block for a fuel pump. [Electric pump fitted]
it has the Riley Elf badgeing on the rocker cover also.  [that could of maybe been swapped over from the original engine]

I have been around minis and mini vans most of my adult life bit the Riley Elf is a bit of a learning curve for me as its older than any minis ive had but it has some of the stuff my older minis did not .
so i think now we have identified it as an 1100 i wont rush into selling it i will remove it and put it to one side and see what happens during the rebuild .
So Thats good news i can remove the engine now as i was going to leave it in till i sold it.
then the car can go on Dollies so i can start doing a bit when i have time.

Cheers Jacko..

Looked it up     Yes 9AD is a  MK11 Riley Elf engine