open chamber vs. closed chamber

[73-charger-383]

I've been trying to find out what the difference is between the two.  A gear-head i work with tried to explain it to me, but i'm not really following.  From what i gather, it's the angle of the exhaust valve in relation to the chamber, but that really doesn't make sense to me.  Can anyone explain it to me (in a way that a pollack can understand)?

thanx,
mike

[Runner]

this is an open chamber head.  notice how the hole chamber is larger (dished in )



this is a closed chamber notice how the chamber is smaller and flat across the deck,  not as open as the other

[Chryco Psycho]

 open has a full round chamber
the closed chamber is D shaped with the area across from the spark plug filled in as per the pix

[73-charger-383]

cool.......now i understand

thanx for taking the time to explain it

[BigBlockSam]

thanks man, now i get it too