With car cranks, if additional weight needs to be added to the heavy side, material is drilled out and "Mallory metal" is pressed into the hole. I don't have any idea what it is or where it comes from, but it is expensive, and heavy!!!

Also, when removing weight from the crank, it is usefull to do what is called "knife edging" the crank. In automotive, there are a couple of reasons:

1.) We have 40 + wt. racing oil dripping onto the crank and being whipped into a vortex.

2.) The knife edge cuts through air (and oil) better than a blunt shape.

Number 2 is the one that will yeild a lil HP for us, especially at the kind of revs that our motors turn..............next