fatjodycat

Can you run open chamber heads on a motor that has closed chamber heads on it? I notice that ads for BBC heads never state whether they are open or closed chamber. I also looked at pistons in the Doug Herbert catalog and they have open chamber, closed chamber, and then saw open/closed chamber. Would a motor with GM closed chamber heads accept lets say the GM "990" open chamber heads? Thanks in advance. Eddie

ARUSSELL

You can put a set of open chamber heads on a closed engine and have no issues other then less compression.

fatjodycat

Thanks.

oldandtired

The closed chamber heads have valve shrouding problems, effecting their flow. It's just a design thing. If you run closed chamber pistons with closed chamber heads, at least the dome assist in the breathing.
Dave

fatjodycat

Thanks Dave. That gives me more ammo for when I decide what to do for some more hp. I have a .30 427 with oval port closed chamber on it. It is a strong motor but I know there's more potential in it. Eddie