Head talk

[poppa]

What are the differences in an open chamber and closed chamber head?

[justcruisin]

the alloy head is closed chamber - eddy. The cast head is open - 346.

[justcruisin]

Closed chamber

[poppa]

What makes it open-closed? The valves look like they are in different spots. They must have a slightly different purpose,operation??

[Cooter]

Open Chamber= IE: Combustion chamber extends all the way out to the outher edge of the cylinder...


Closed Chamber= IE: Combustion Chamber only extends HALF way across cylinder , and is shaped like a "D"...


Smaller chamber, more compression, IE; more power..Valves in same place on production head..

[justcruisin]

If you have a look at the edelbrock heads on thier site you will see they offer both open and closed chamber heads. The open version is the same as the closed with the addition of a .100" cut into the chamber which opens up the chamber to an open design, same head, same valve positions. The closed version offers a smaller chamber for greater compression but its biggest advantage in a street pump gas engine is it offers a flat area level with the head surface above the piston so that a tight squeeze can be obtained to help deter detonation.

[Budnicks]

That was a good explanation... 

[poppa]

That was a good explanation... 

Agreed,thank you all.