help me understand difference between open/close chamber heads

[71dustar]

since i have a magnum motor, i know my heads are a closed chamber just from reading up and listening from everyone hear but i don't fully understand what makes a head a CC vs an OC.

 

[C130 Chief]

The domed area of an "Open" chamber will extend to the diameter of the cylinder bore. A "Closed" chamber has a diameter which is smaller than the bore, typically a lot smaller. The deck surface will extend into the chamber creating a "Quench" area between the head and the flat portion of the piston. The advantage is fuel efficiency, detonation resistance, and emissions. However, valve shrouding can become an issue if the chamber is closed too much. Pop the head off a Chevy stovebolt 6 for a good example of a true "closed" chamber.

 

[toolmanmike]

This photo is of Mopar big block heads but it illustrates the difference. The head on the left is a closed chamber design where the one on the right is an open chamber. The other photos show differences. toolmanmike