Starting Out

The first step is to scribe the basic shape of the intended chamber. The intent here is to grind a smooth angle from the scribed line over to the existing chamber top, without removing any of the chamber top and putting myself at risk of cutting another water jacket.

Basic Shape

Here is the basic shape of the chamber.

Bottom Out

I had the unleaded inserts set lower than the chamber "bottom" (really the chamber top, but in this orientation, it's the bottom). So, to make it all level, I used this stone.

Beaks

Next, I drew in the basic beaks I intended to end up with. Note how much real estate there is between the drawn-in beaks, and the edges of the real ones!

Edge Grind

Here is the tool I used to grind the edges of the chambers. It's a pretty rough stone, and does a pretty quick job of removing metal. I'll go back over it all with a smoother stone for that high-speed shine...

Shame on Me!

And here we see the chambers ground out all the way to the scribed line. I'm still leaving the chamber tops as original as possible, so as to stay clear of those water jackets! I wonder if there is a clinical term for "water jacket phobia".

Odd Shape

It really looks odd when you leave some beaks in, and widen out the chamber!

Closer

From another angle, you see the new beak. Note that I still have not changed the chamber top shape too much.