A saw with the bosses...
Attachment 40687
Printable View
A saw with the bosses...
Attachment 40687
It's possible those holes might have served a purpose in the production process with no design intent at all for the end consumer. Perhaps those holes are required for the casting process or they might even be used in the assembly process, such as a grab point for robots, etc.
As an example, it's not uncommon to find such details or features on automotive parts which are used only for the production process. This includes various mounting holes, slots, and sometimes even complete brackets that are never used again after the vehicle is assembled.
Those are speed holes.