I use a slitter saw to cut piston ring grooves, but it should work equally well cutting fins on IC engine cylinders.
There is a variety of reasons I did it the hard way this time. Next time will definately have more thought put into it. I am thinking perhaps 5 saw blades spaced and ganged together.
Do you cut them in reverse on your mill, or is this a set up shot?
I think cutting in reverse is better since the chuck can't unscrew from the table spindle. I've never tried that yet.
No worries over it Pat, I was just curious, and what Rich says is a very good point.
You might have done it by mistake Pat, but it turned out OK and if you take into account what Rich has said, it was correct as well.