mini0998 wrote:
I understand there is a 15AC alternator with external regulator (all metal back), and the 15ACR with internal regulator (has black plastic cover on the back), but the one that I have looks exactly like the 15AC external regulated one (all metal back), but has an internal regulator.
I think you'll find it's the other way round. The 15AC has a black plastic
half cover and requires an external 4TR or 8TR regulator (see photo below). The 15ACR has a flat metal back and no plastic cover.
Be aware that the alternators fitted to the Australian Mini range from 1969 were manufactured by Lucas Australia and have this marking clearly shown on the outside case. The UK had their own version of 15AC and 15ACR so don't get them confused.
There are several versions of the Australian 15AC alternator, identified by the Lucas eight digit part number embossed on the case. They all start with 629212xx but the last two digits will indicate the vehicle application. There is no internal difference between these 15AC's, just the front and rear alloy housing dimensions that will vary as they will be for different vehicle mounting brackets. For example, the part number on the 15AC in the picture is 62921215A, which the Lucas catalogue says is for a Datsun 1600. If I was fitting this to a Mini I would need to check the mounting dimensions to see if it needed alteration to the bracket.
The Lucas part number for an Australian Mini 15AC is 62921207, and for the later 15ACR-2D with inbuilt regulator is 62921219. If you are wanting originality they are the ones to look for.
Attachment:
Lucas 15AC 1.jpg
Attachment:
Lucas 15AC 2.jpg
Attachment:
Lucas 8TR Regulator.jpg