Mystery Crankcase

[ajsph]

I have more G 12 Crankcases, but one is different from the others, the different ones has 3 dots on the surface where the chaincase fits, I have never seen a chaincase with 3 holes where the dots will fit, could anyone please help to identify the crankcase
Regards
Poul

DSC00622_1.jpg

[Rob Harknett]

Has it not got an engine number to ID it?

[ajsph]

G12/ x7920
Poul

[TrevorCSR]

You say they are 'dots'. They look very much like short studs. Might be translation, I know. The angle of the picture is not very good. But whatever, in the 65 years or so anything could have been done to your cases. How big is the centre hole? Looks like it could have been bored out for some reason, maybe to fit an oilseal.

[ajsph]

Yes it is studs dia. 1/4", the hole is 2 5/8", I think it is standard size, because I have one more crankcase without studs but the hole has the same size.
Poul

[saltbox alf]

Are the holes threaded, if so it might have had a different chaincase in the past. Tin one?

[TrevorCSR]

The centre hole in my cases measures 2 1/32" 51.63mm. I know as I intend to fit an oil seal here. Can be bored to 52mm and use off the shelf oil seals to fit

[ajsph]

yes the holes are threaded and is in the right place for the alu chaincase.
I have a crankcase for dynamo it has the smaller centerhole, and I have an alternator crankcase it has the bigger centerhole.
Poul