215cc heads Vs 205cc heads, where is the cc measured?
When a head is call as 215cc or 205 intake runner, at what points is that measured?

 

That is the volume of the intake port itself. Meaning you can fill it with 215cc of liquid. The smaller the port and the better the flow the more power throughout the RPM range. Usually attributed to port velocity.

 

OK, I got that, but from what piont in the intake piont to what piont.

 

I guess its when you flip the head on its side the "fill" the intake port with liquid, with the valve closed, and you see how much it holds, same as the combustion chamber.

 

OK, but that will include the size of the bowl and the runner.

 

Yup, that's the way it's done: bowl plus runner. To most builders, it's actually the smallest area or the 'throat' of the port that is critical, but on a given engine with no weird, one-off machining, the volume is a good indicator of same. (e.g. a 240 cc BBF port could not be considered equivalent in any way to a 240 cc. SBC.) You set the head up with the manifold gasket surface horizontal, and you fill the port from a burette until it is level full to the gasket surface, then read off how much it held.