Mag case R numbers
 

Hello all.

Just looking for authoruitative source for the use of the cases in each modle year..and type.

I have noticed eg all MFI 2.4T's seem to have the rare 91.5mm spigot 7r case..

And I know that 1969 S's have the 1R case..

Is there any documentation of all this please?

Kind regards
David

My books show 72 engines (2.4) to have 4R cases and 73's and later to have 7R cases. Don't know the others but what do you want to know. The 7R case has the extra webbing on the bottom of the main webs and the extra material in the flywheel area. If you are building an engine with aluminum cylinders and high revs you need the 7R or an aluminum case. Bruce Andersons 911 performance handbook has this information in it.

-Andy