We don't know how sophisticated their machining centers are. If they are all cnc stuff they could machine the pockets for the seats and the bores for the guides in the same machine with a change of tooling. Just thinking out loud.
Actually, this very topic was being discussed over on speedtalk.com and I'd say most likely if SM or whoever is doing the finish work is using some form of CNC machining, I'd suspect they are using a Newen Epoch or similar machine.
I doubt they are tooling up a CNC machine just to cut seats. Most likely they are using a regular seat and guide machine. If you are setting up to cut say 2.02/1.60 valves, you can do a 4 cylinder head in about 10 minutes max once you have the tooling set up. So I'd say floor to floor in 12 minutes per head. That's 4 heads an hour, 32 heads a day from just one machine. Doesn't sound like a lot, but it really is for just one machine. And if you have your crap together you could cut some time off of that.
