I drilled my truck brake drums.
My brakes should be cleaner, quieter, and have less drag due to the lack of brake dust buildup. Don't freak out, I only drilled 64 holes in each drum.
Yes, you can buy drilled drums and yes they are safe. I am very excited to see how well it works.
Don't worry, there is a pattern to the holes, it only looks random. The vent holes are .2" and the big air inlet holes are 1/2". 64 holes, with 3 stages on each if you count drilling and chamfering. That comes out to 384 holes drilled/chamfered. 400 holes if you count chamfering both the inside and outside of the inlet holes. Yes, it took forever. Yes, I broke and had to sharpen many drill bits. Some are gone forever, in that drill bit heaven in the sky...
I will do better on the next pair.
The car drums are next.
Template in drum
Pilot holes
Reamed holes
Inside
Outside
Finished pair